V1.10.1: a phone-friendly layout, easier navigation, paged encounters

- The main destinations are always on screen: Campaigns, Campaign and
  Party (for the campaign last visited, from any page) and Account. They
  are links along the top bar on a wide screen, and a bar along the
  bottom on a phone or small tablet (900px or less).
- Nothing floats over the page on a phone: the dice roller is the last
  button of the bottom bar, and quick stats sits in the top bar.
- The campaign page and the character sheet start with a row of links to
  their sections.
- On a small screen every table is a stack of labelled cards, rows of
  controls wrap, fields shrink to fit, and things to tap are bigger.
- The encounter list is paged, ten to a page, as is the archived list.
  Moving an encounter still works across pages.
- Text boxes with no type given, and native checkboxes and dropdowns, now
  match the dark theme. Long monster notes and item descriptions wrap
  inside their table cell.
- All packages at version 1.10.1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -14,10 +14,10 @@ monsters, and a real-time encounter/combat tracker.
 | `docs/CHARACTERS.md` | Building a character, every number on the sheet, levels, money, permissions |
 | `docs/WEAPONS.md` | The weapon pool, weapon levels and how damage grows |
 | `docs/SPELLS.md` | The spell list, who can use which spells, the spell library |
-| `docs/ITEMS.md` | The item pool and character inventory |
-| `docs/ENCOUNTERS.md` | Battles and NPC quests, turns, rewards, what players see |
+| `docs/ITEMS.md` | The item pool, character inventory, items for sale |
+| `docs/ENCOUNTERS.md` | Battles and NPC quests, turns, rewards, trade, what players see |
 | `docs/MONSTERS.md` | The monster list and built-in bestiary |
-| `docs/NPCS.md` | Non-player characters |
+| `docs/NPCS.md` | Non-player characters, what they sell and the rates they change money at |
 
 `CLAUDE_BUILD_PROMPT.md`, `docs/GAME_RULES_REFERENCE.md` and
 `docs/ROLL_YOUR_CHARACTER.md` are the original specifications the first
@@ -25,6 +25,25 @@ version was built from. The app has since moved on in places (gear levels,
 the builder's story steps, picking a motivation); the documents above are the
 current behaviour.
 
+## Getting around
+
+The same four destinations are always on screen: **Campaigns** (the list),
+**Campaign** and **Party** (for the campaign you were last in, from any page,
+including a character sheet or an encounter) and **Account**.
+
+- On a wide screen they are links along the top bar, and the dice roller
+  floats at the bottom left.
+- On a phone or small tablet (900px wide or less) they are a bar along the
+  bottom of the screen, with the **dice roller** as its last button. Nothing
+  floats over the page: on a character sheet the ⚡ quick stats button sits in
+  the top bar.
+- The campaign page and the character sheet are long, so each starts with a
+  row of **section links** (Characters, Encounters, NPCs, Monsters...) that
+  jump straight to that part of the page.
+- On a small screen every table (weapons, items, spells, monsters, the party
+  overview) is shown as a stack of cards, one per row, with each figure
+  labelled, and rows of controls wrap rather than run off the side.
+
 ## Stack
 
 - **Backend:** Node.js + Express, JavaScript, Prisma ORM, PostgreSQL, Socket.io, JWT auth (bcrypt + jsonwebtoken), zod validation.
@@ -80,8 +99,12 @@ cd backend
 npm run seed:hollowcrown
 ```
 
-On a server, apply new migrations with `npx prisma migrate deploy`. Change
-your password from the account page (click your name in the top bar).
+On a server, after pulling a new version, run `npm run deploy` in `backend`
+and then restart the backend. It applies new migrations **and** regenerates
+the Prisma client; without the second half the server keeps running with the
+old data model and pages that use anything new fail to load (for example
+"Could not load this encounter"). Change your password from the account page
+("Account" in the navigation).
 
 ## Tests
 

backend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "backend",
-  "version": "1.3.0",
+  "version": "1.10.1",
   "private": true,
   "type": "commonjs",
   "main": "src/index.js",
@@ -10,11 +10,12 @@
   "scripts": {
     "dev": "node --watch src/index.js",
     "start": "node src/index.js",
-    "test": "node --experimental-vm-modules node_modules/.bin/jest",
+    "test": "jest",
     "docs:lists": "node scripts/generate-doc-lists.js",
     "prisma:migrate": "prisma migrate dev",
     "prisma:generate": "prisma generate",
     "prisma:seed": "prisma db seed",
+    "deploy": "prisma migrate deploy && prisma generate",
     "seed:hollowcrown": "node prisma/seed-hollowcrown.js",
     "prisma:studio": "prisma studio"
   },

backend/prisma/migrations/20261007090000_silver_and_copper/migration.sql

@@ -0,0 +1,10 @@
+-- CreateEnum: the three coins. Silver is worth 0.1 gold, copper 0.01 gold.
+CREATE TYPE "Currency" AS ENUM ('GOLD', 'SILVER', 'COPPER');
+
+-- AlterTable: a character's purse holds each coin separately
+ALTER TABLE "characters" ADD COLUMN "silver" INTEGER NOT NULL DEFAULT 0;
+ALTER TABLE "characters" ADD COLUMN "copper" INTEGER NOT NULL DEFAULT 0;
+
+-- AlterTable: every ledger entry and coin reward is in one coin; all existing ones are gold
+ALTER TABLE "gold_transactions" ADD COLUMN "currency" "Currency" NOT NULL DEFAULT 'GOLD';
+ALTER TABLE "encounter_rewards" ADD COLUMN "currency" "Currency" NOT NULL DEFAULT 'GOLD';

backend/prisma/migrations/20261007120000_death_saves/migration.sql

@@ -0,0 +1,4 @@
+-- AlterTable: death saves, counted while a character is at 0 HP
+ALTER TABLE "characters" ADD COLUMN "deathSaveSuccesses" INTEGER NOT NULL DEFAULT 0,
+ADD COLUMN "deathSaveFailures" INTEGER NOT NULL DEFAULT 0,
+ADD COLUMN "stable" BOOLEAN NOT NULL DEFAULT false;

backend/prisma/migrations/20261007150000_encounter_target/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable: the combatant currently marked as the target
+ALTER TABLE "encounters" ADD COLUMN "targetParticipantId" TEXT;

backend/prisma/migrations/20261007170000_encounter_targets/migration.sql

@@ -0,0 +1,9 @@
+-- AlterTable: several combatants can be marked as targets at once (an area attack)
+ALTER TABLE "encounters" ADD COLUMN "targetParticipantIds" TEXT[] DEFAULT ARRAY[]::TEXT[];
+
+-- Carry over a single target marked before this.
+UPDATE "encounters"
+SET "targetParticipantIds" = ARRAY["targetParticipantId"]
+WHERE "targetParticipantId" IS NOT NULL;
+
+ALTER TABLE "encounters" DROP COLUMN "targetParticipantId";

backend/prisma/migrations/20261007190000_area_attack_ac_penalty/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable: how much an area attack adds to each AC per extra target
+ALTER TABLE "campaigns" ADD COLUMN "areaAttackAcPenalty" INTEGER NOT NULL DEFAULT 2;

backend/prisma/migrations/20261007210000_spell_revives/migration.sql

@@ -0,0 +1,5 @@
+-- AlterTable: spells that bring back the dead
+ALTER TABLE "spells" ADD COLUMN "revives" BOOLEAN NOT NULL DEFAULT false;
+
+-- The library's two revival spells, wherever a campaign already has them.
+UPDATE "spells" SET "revives" = true WHERE "name" IN ('Revivify', 'Raise Dead');

backend/prisma/migrations/20261007230000_cash_currency/migration.sql

@@ -0,0 +1,6 @@
+-- AlterEnum: cash ($), a modern currency for crossover worlds. It has no fixed
+-- worth in gold, so it is never exchanged or used to make change.
+ALTER TYPE "Currency" ADD VALUE 'CASH';
+
+-- AlterTable: cash is counted on its own, like each coin
+ALTER TABLE "characters" ADD COLUMN "cash" INTEGER NOT NULL DEFAULT 0;

backend/prisma/migrations/20261008100000_trade/migration.sql

@@ -0,0 +1,28 @@
+-- AlterTable: an NPC who changes money does it at their own rate, this many
+-- gold for that much cash. Both are null for an NPC who does not.
+ALTER TABLE "npcs" ADD COLUMN "exchangeGold" INTEGER;
+ALTER TABLE "npcs" ADD COLUMN "exchangeCash" INTEGER;
+
+-- CreateTable: something for sale, by an NPC or at an encounter itself
+CREATE TABLE "sale_offers" (
+    "id" TEXT NOT NULL,
+    "campaignId" TEXT NOT NULL,
+    "npcId" TEXT,
+    "encounterId" TEXT,
+    "weaponId" TEXT,
+    "itemId" TEXT,
+    "price" INTEGER NOT NULL,
+    "currency" "Currency" NOT NULL DEFAULT 'GOLD',
+    "level" INTEGER NOT NULL DEFAULT 1,
+    "stock" INTEGER,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "sale_offers_pkey" PRIMARY KEY ("id")
+);
+
+-- AddForeignKey
+ALTER TABLE "sale_offers" ADD CONSTRAINT "sale_offers_campaignId_fkey" FOREIGN KEY ("campaignId") REFERENCES "campaigns"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "sale_offers" ADD CONSTRAINT "sale_offers_npcId_fkey" FOREIGN KEY ("npcId") REFERENCES "npcs"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "sale_offers" ADD CONSTRAINT "sale_offers_encounterId_fkey" FOREIGN KEY ("encounterId") REFERENCES "encounters"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "sale_offers" ADD CONSTRAINT "sale_offers_weaponId_fkey" FOREIGN KEY ("weaponId") REFERENCES "weapons"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "sale_offers" ADD CONSTRAINT "sale_offers_itemId_fkey" FOREIGN KEY ("itemId") REFERENCES "items"("id") ON DELETE CASCADE ON UPDATE CASCADE;

backend/prisma/schema.prisma

@@ -118,6 +118,16 @@ enum RewardType {
   ITEM
 }
 
+// The money a character carries. The coins' worth is fixed in utils/grants.js:
+// 1 gold = 10 silver = 100 copper. Cash ($) is modern money for crossover
+// worlds; it has no worth in coins and is never exchanged for them.
+enum Currency {
+  GOLD
+  SILVER
+  COPPER
+  CASH
+}
+
 enum NoteVisibility {
   DM_ONLY
   SHARED
@@ -160,6 +170,9 @@ model Campaign {
   skipMotivationRoll Boolean  @default(false)
   // Off: players see only a health bar for monsters and NPCs, not the numbers.
   showMonsterHp      Boolean  @default(true)
+  // An attack on several targets is harder to land: each target's AC counts
+  // as this much higher for every target beyond the first. 0 turns it off.
+  areaAttackAcPenalty Int     @default(2)
   ownerId            String
   // Set while the campaign is archived: kept in full, but moved off the main
   // list and closed to new members until the DM restores it.
@@ -175,6 +188,7 @@ model Campaign {
   monsters   Monster[]
   npcs       Npc[]
   encounters Encounter[]
+  saleOffers SaleOffer[]
   notes      Note[]
   locations  Location[]
 
@@ -256,13 +270,23 @@ model Character {
 
   currentHp     Int     @default(0)
   tempHp        Int     @default(0)
+  // Death saves, counted while the character is at 0 HP (utils/hp.js). Three
+  // failures is dead; three successes sets `stable` and clears the tallies.
+  deathSaveSuccesses Int     @default(0)
+  deathSaveFailures  Int     @default(0)
+  stable             Boolean @default(false) // at 0 HP but no longer rolling
   armorBonus    Int     @default(0) // flat AC bonus from equipped armor/shield
   speedOverride Int?
 
   // The next three are composed by the builder from the player's picks
   // (game/data/characterOptions.js). After that only the DM can edit them.
   specialAbilities String? // shown in the quick-stats panel
+  // The purse: each coin (and cash) is counted on its own and only changes through the
+  // money ledger (GoldTransaction).
   gold             Int     @default(0)
+  silver           Int     @default(0)
+  copper           Int     @default(0)
+  cash             Int     @default(0) // whole dollars
 
   background   String?
   appearance   String?
@@ -349,6 +373,7 @@ model Weapon {
   campaign Campaign          @relation(fields: [campaignId], references: [id], onDelete: Cascade)
   assigned CharacterWeapon[]
   rewards  EncounterReward[]
+  offers   SaleOffer[]
 
   @@map("weapons")
 }
@@ -383,6 +408,7 @@ model Item {
   campaign Campaign        @relation(fields: [campaignId], references: [id], onDelete: Cascade)
   held     InventoryItem[]
   rewards  EncounterReward[]
+  offers   SaleOffer[]
 
   @@map("items")
 }
@@ -403,12 +429,14 @@ model InventoryItem {
   @@map("inventory_items")
 }
 
-// Ledger behind Character.gold: every change to the balance is one row here.
+// Ledger behind a character's purse: every change to a coin balance is one
+// row here. (The name predates silver and copper.)
 model GoldTransaction {
   id           String   @id @default(cuid())
   characterId  String
+  currency     Currency @default(GOLD) // which coin this entry is in
   amount       Int // signed: positive = gained, negative = spent
-  balanceAfter Int
+  balanceAfter Int // that coin's balance afterwards
   reason       String?
   createdById  String?
   createdAt    DateTime @default(now())
@@ -436,6 +464,9 @@ model Spell {
   duration    String?
   description String?
   isStartingOption Boolean @default(false)
+  // Brings back the dead: a character who can cast it may revive a dead ally
+  // on their turn in a battle (encounters.routes.js).
+  revives     Boolean @default(false)
 
   campaign Campaign         @relation(fields: [campaignId], references: [id], onDelete: Cascade)
   known    CharacterSpell[]
@@ -499,10 +530,15 @@ model Npc {
   maxHp       Int?
   attackBonus Int?
   damageDice  String?
+  // A money changer swaps gold and cash at their own rate: exchangeGold gold
+  // for exchangeCash cash, either way. Both null: this NPC does not exchange.
+  exchangeGold Int?
+  exchangeCash Int?
   createdAt   DateTime       @default(now())
 
   campaign             Campaign               @relation(fields: [campaignId], references: [id], onDelete: Cascade)
   encounterAppearances EncounterParticipant[]
+  wares                SaleOffer[]
 
   @@map("npcs")
 }
@@ -516,6 +552,10 @@ model Encounter {
   currentRound Int             @default(1)
   // Whose turn it is in a battle; null until the fight starts.
   activeParticipantId String?
+  // Who is being attacked (or healed) right now, shown to everyone, in the
+  // order they were picked. More than one makes it an area attack. Picked by
+  // the DM or by the player on turn, and cleared when the turn passes.
+  targetParticipantIds String[] @default([])
   description  String? // the scene / objective, shown to everyone
   dmNotes      String? // never sent to players
   // Where the scene takes place. While the encounter is in progress, the
@@ -533,6 +573,7 @@ model Encounter {
   location     Location?              @relation(fields: [locationId], references: [id], onDelete: SetNull)
   participants EncounterParticipant[]
   rewards      EncounterReward[]
+  wares        SaleOffer[]
 
   @@map("encounters")
 }
@@ -544,7 +585,8 @@ model EncounterReward {
   id          String     @id @default(cuid())
   encounterId String
   type        RewardType
-  gold        Int? // GOLD
+  gold        Int? // GOLD: how many coins
+  currency    Currency   @default(GOLD) // GOLD: which coin they are
   weaponId    String? // WEAPON
   itemId      String? // ITEM
   quantity    Int        @default(1)
@@ -561,6 +603,33 @@ model EncounterReward {
   @@map("encounter_rewards")
 }
 
+// Something for sale: a weapon or item from the campaign pools, at a price.
+// It belongs to an NPC (and is on offer wherever that NPC is met) or to an
+// encounter itself (a stall, a vending machine). Only the DM sets these up;
+// players see them, and buy, in a quest encounter in progress
+// (encounters.routes.js).
+model SaleOffer {
+  id          String   @id @default(cuid())
+  campaignId  String
+  npcId       String? // exactly one of npcId / encounterId is set
+  encounterId String?
+  weaponId    String? // exactly one of weaponId / itemId is set
+  itemId      String?
+  price       Int // for one, in `currency`
+  currency    Currency @default(GOLD)
+  level       Int      @default(1) // gear level it is handed over at
+  stock       Int? // how many are left; null = no limit
+  createdAt   DateTime @default(now())
+
+  campaign  Campaign   @relation(fields: [campaignId], references: [id], onDelete: Cascade)
+  npc       Npc?       @relation(fields: [npcId], references: [id], onDelete: Cascade)
+  encounter Encounter? @relation(fields: [encounterId], references: [id], onDelete: Cascade)
+  weapon    Weapon?    @relation(fields: [weaponId], references: [id], onDelete: Cascade)
+  item      Item?      @relation(fields: [itemId], references: [id], onDelete: Cascade)
+
+  @@map("sale_offers")
+}
+
 // A row per combatant in an encounter — a character, a monster or an NPC.
 // A monster's currentHp/maxHp live here, per instance. A character's HP has
 // one source of truth, the Character row: encounters read and write that, and

backend/src/game/data/spellsLibrary.js

@@ -115,7 +115,7 @@ const SPELL_LIBRARY = [
   { key: 'nondetection', name: 'Nondetection', level: 3, school: 'Abjuration', castingTime: '1 action', range: 'Touch', duration: '8 hours', description: 'Hide a target from divination magic.', classes: ['BARD', 'RANGER', 'WIZARD'] },
   { key: 'protection-from-energy', name: 'Protection from Energy', level: 3, school: 'Abjuration', castingTime: '1 action', range: 'Touch', duration: 'Concentration, up to 1 hour', description: 'Resistance to one damage type of your choice.', classes: ['CLERIC', 'DRUID', 'RANGER', 'SORCERER', 'WIZARD'] },
   { key: 'remove-curse', name: 'Remove Curse', level: 3, school: 'Abjuration', castingTime: '1 action', range: 'Touch', duration: 'Instantaneous', description: 'Lift a curse from a creature or object.', classes: ['CLERIC', 'PALADIN', 'WARLOCK', 'WIZARD'] },
-  { key: 'revivify', name: 'Revivify', level: 3, school: 'Necromancy', castingTime: '1 action', range: 'Touch', duration: 'Instantaneous', description: 'A creature that died within the last minute returns to life with 1 hit point.', classes: ['CLERIC', 'PALADIN'] },
+  { key: 'revivify', name: 'Revivify', level: 3, school: 'Necromancy', castingTime: '1 action', range: 'Touch', duration: 'Instantaneous', description: 'A creature that died within the last minute returns to life with 1 hit point.', revives: true, classes: ['CLERIC', 'PALADIN'] },
   { key: 'sleet-storm', name: 'Sleet Storm', level: 3, school: 'Conjuration', castingTime: '1 action', range: '150 feet', duration: 'Concentration, up to 1 minute', description: 'Freezing rain falls in a 40-foot-radius cylinder, icing the ground.', classes: ['DRUID', 'SORCERER', 'WIZARD'] },
   { key: 'slow', name: 'Slow', level: 3, school: 'Transmutation', castingTime: '1 action', range: '120 feet', duration: 'Concentration, up to 1 minute', description: 'Up to six creatures are hindered, halving their speed and worse.', classes: ['SORCERER', 'WIZARD'] },
   { key: 'spirit-guardians', name: 'Spirit Guardians', level: 3, school: 'Conjuration', castingTime: '1 action', range: 'Self (15-foot radius)', duration: 'Concentration, up to 10 minutes', description: 'Protective spirits swirl around you, damaging enemies that enter.', damageDice: '3d8', classes: ['CLERIC'] },
@@ -150,7 +150,7 @@ const SPELL_LIBRARY = [
   { key: 'insect-plague', name: 'Insect Plague', level: 5, school: 'Conjuration', castingTime: '1 action', range: '300 feet', duration: 'Concentration, up to 10 minutes', description: 'A swarm of biting, stinging insects fills a 20-foot-radius sphere.', damageDice: '4d10', classes: ['CLERIC', 'DRUID', 'SORCERER'] },
   { key: 'legend-lore', name: 'Legend Lore', level: 5, school: 'Divination', castingTime: '10 minutes', range: 'Self', duration: 'Instantaneous', description: 'Learn what you know, or have heard, about a name, place, or object.', classes: ['BARD', 'CLERIC', 'WIZARD'] },
   { key: 'mass-cure-wounds', name: 'Mass Cure Wounds', level: 5, school: 'Evocation', castingTime: '1 action', range: '60 feet', duration: 'Instantaneous', description: 'Up to six creatures in a 30-foot-radius sphere regain hit points.', classes: ['BARD', 'CLERIC', 'DRUID'] },
-  { key: 'raise-dead', name: 'Raise Dead', level: 5, school: 'Necromancy', castingTime: '1 hour', range: 'Touch', duration: 'Instantaneous', description: 'Return a dead creature to life, as long as its body is mostly intact.', classes: ['BARD', 'CLERIC', 'PALADIN'] },
+  { key: 'raise-dead', name: 'Raise Dead', level: 5, school: 'Necromancy', castingTime: '1 hour', range: 'Touch', duration: 'Instantaneous', description: 'Return a dead creature to life, as long as its body is mostly intact.', revives: true, classes: ['BARD', 'CLERIC', 'PALADIN'] },
   { key: 'wall-of-force', name: 'Wall of Force', level: 5, school: 'Evocation', castingTime: '1 action', range: '120 feet', duration: 'Concentration, up to 10 minutes', description: 'An invisible wall of force springs into existence, impenetrable to physical force.', classes: ['WIZARD'] },
   { key: 'wall-of-stone', name: 'Wall of Stone', level: 5, school: 'Evocation', castingTime: '1 action', range: '120 feet', duration: 'Concentration, up to 10 minutes', description: 'A nonmagical wall of solid stone springs into existence.', classes: ['DRUID', 'SORCERER', 'WIZARD'] },
 ];

backend/src/routes/api.integration.test.js

@@ -584,7 +584,7 @@ describe('hit points', () => {
     const full = (await patch(playerAuth, { currentHp: 9999 })).body.character;
     expect(full.currentHp).toBe(level5.sheet.hp.max);
 
-    expect((await patch(playerAuth, { currentHp: -50 })).body.character.currentHp).toBe(0);
+    expect((await patch(playerAuth, { currentHp: -1 })).body.character.currentHp).toBe(0);
 
     await patch(playerAuth, { currentHp: 9999 });
     const level1 = (await patch(dmAuth, { level: 1 })).body.character;
@@ -613,7 +613,7 @@ describe('hit points', () => {
     expect((await combatant()).currentHp).toBe(maxHp - 1);
 
     // The tracker is clamped like the sheet, and can't give a character a different max.
-    await request(app).patch(`/encounters/${encounterId}/participants/${participantId}`).set(dmAuth).send({ currentHp: -20, maxHp: 500 });
+    await request(app).patch(`/encounters/${encounterId}/participants/${participantId}`).set(dmAuth).send({ currentHp: -1, maxHp: 500 });
     expect(await sheetHp()).toBe(0);
     expect((await combatant()).maxHp).toBe(maxHp);
 
@@ -674,6 +674,39 @@ describe('money tracker', () => {
       [15, 15, 'Starting gold', 'Player'],
     ]);
   });
+
+  itIfDb('keeps cash apart from the coins', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('cash');
+    const create = (name) => request(app).post(`/campaigns/${campaign.id}/characters`).set(playerAuth).send({ name });
+    const characterId = (await create('Drifter')).body.character.id;
+    const money = (body) => request(app).post(`/characters/${characterId}/gold`).set(playerAuth).send(body);
+
+    await money({ amount: 5 });
+    const paid = await money({ amount: 40, currency: 'CASH', reason: 'Odd job' });
+    expect(paid.status).toBe(201);
+    expect(paid.body).toMatchObject({ gold: 5, cash: 40 });
+    expect(paid.body.transaction).toMatchObject({ currency: 'CASH', amount: 40, balanceAfter: 40 });
+
+    // Cash is paid in cash alone: gold doesn't cover it, and it doesn't cover gold.
+    const overspend = await money({ amount: -41, currency: 'CASH' });
+    expect(overspend.status).toBe(400);
+    expect(overspend.body.error).toContain('$40');
+    expect((await money({ amount: -6 })).status).toBe(400);
+    const spent = await money({ amount: -15, currency: 'CASH', reason: 'Diner' });
+    expect(spent.body).toMatchObject({ gold: 5, silver: 0, copper: 0, cash: 25 });
+    expect(spent.body.transactions).toHaveLength(1);
+
+    // It has no worth in coins, so it can't be exchanged, and it only moves through the ledger.
+    const exchange = (body) => request(app).post(`/characters/${characterId}/gold/exchange`).set(playerAuth).send(body);
+    expect((await exchange({ from: 'CASH', to: 'GOLD', amount: 10 })).status).toBe(400);
+    expect((await exchange({ from: 'GOLD', to: 'CASH', amount: 1 })).status).toBe(400);
+    expect((await request(app).patch(`/characters/${characterId}`).set(dmAuth).send({ cash: 999 })).status).toBe(400);
+
+    const sheet = (await request(app).get(`/characters/${characterId}`).set(playerAuth)).body.character;
+    expect(sheet.cash).toBe(25);
+    const listed = (await request(app).get(`/campaigns/${campaign.id}/characters`).set(dmAuth)).body.characters;
+    expect(listed.find((c) => c.id === characterId).cash).toBe(25);
+  });
 });
 
 describe('starting options', () => {
@@ -956,7 +989,11 @@ describe('encounters', () => {
 
     await request(app).post(`${e}/participants`).set(dmAuth).send({ characterId: heroId });
     const playerView = byName((await request(app).get(e).set(playerAuth)).body.encounter);
-    expect(playerView['Mayor Orla'].npc).toEqual({ id: mayor.id, name: 'Mayor Orla', role: 'Mayor', disposition: 'HOSTILE', description: 'Tired but kind.' });
+    // What a player gets is exactly this: the public face, plus what the NPC trades (nothing, here).
+    expect(playerView['Mayor Orla'].npc).toEqual({
+      id: mayor.id, name: 'Mayor Orla', role: 'Mayor', disposition: 'HOSTILE', description: 'Tired but kind.',
+      exchangeGold: null, exchangeCash: null, wares: [],
+    });
 
     // Deleting an NPC takes it out of the scenes it was in.
     expect((await request(app).delete(`${c}/npcs/${hermit.id}`).set(dmAuth)).status).toBe(204);
@@ -1418,6 +1455,35 @@ describe('default content library', () => {
     expect((await request(app).get(`/campaigns/${campaign.id}/monsters`).set(dmAuth)).body.monsters).toHaveLength(1);
     expect((await request(app).get(`/campaigns/${campaign.id}/monsters`).set(playerAuth)).status).toBe(403);
 
+    // Every library monster carries the whole stat block.
+    for (const m of listRes.body.monsters) {
+      expect(m).toMatchObject({
+        challengeRating: expect.any(String),
+        ac: expect.any(Number),
+        maxHp: expect.any(Number),
+        speed: expect.any(Number),
+        attackBonus: expect.any(Number),
+        damageDice: expect.any(String),
+        notes: expect.any(String),
+      });
+      for (const a of ['str', 'dex', 'con', 'int', 'wis', 'cha']) expect(m[`${a}Score`]).toEqual(expect.any(Number));
+    }
+
+    // A hand-made monster takes the whole stat block, and every field can be changed afterwards.
+    const block = {
+      name: 'Gloamling', challengeRating: '1/2', ac: 13, maxHp: 18, speed: 40, attackBonus: 4, damageDice: '1d6+2 necrotic',
+      strScore: 8, dexScore: 16, conScore: 12, intScore: 6, wisScore: 11, chaScore: 5,
+      specialTrait: 'Shadow Step', notes: 'Fly 30. Resists necrotic.',
+    };
+    const made = await request(app).post(`/campaigns/${campaign.id}/monsters`).set(dmAuth).send(block);
+    expect(made.status).toBe(201);
+    expect(made.body.monster).toMatchObject(block);
+    const patchMonster = (auth, body) => request(app).patch(`/campaigns/${campaign.id}/monsters/${made.body.monster.id}`).set(auth).send(body);
+    const edited = await patchMonster(dmAuth, { speed: 20, wisScore: 14, challengeRating: '1', specialTrait: null });
+    expect(edited.status).toBe(200);
+    expect(edited.body.monster).toMatchObject({ ...block, speed: 20, wisScore: 14, challengeRating: '1', specialTrait: null });
+    expect((await patchMonster(playerAuth, { ac: 1 })).status).toBe(403);
+
     const playerAddRes = await request(app)
       .post(`/campaigns/${campaign.id}/monsters/from-library`)
       .set(playerAuth)
@@ -1839,7 +1905,9 @@ describe('what a player may see', () => {
     expect(dm.Ogre.hpPercent).toBeUndefined();
 
     await request(app).patch(`${e}/participants/${ogreRow.id}`).set(dmAuth).send({ currentHp: 0 });
-    expect((await view(playerAuth)).Ogre.hpPercent).toBe(0);
+    // At 0 HP it is out of the fight, and out of the players' sight.
+    expect((await view(playerAuth)).Ogre).toBeUndefined();
+    expect((await view(dmAuth)).Ogre).toMatchObject({ currentHp: 0, hidden: true });
   });
 });
 
@@ -1896,6 +1964,15 @@ describe('initiative', () => {
     expect(playerView.Goblin.initiative).toBe(12);
     expect(playerView.Quick.character.userId).toBeTruthy();
 
+    // Only the die stops at 20: a natural 20 plus a bonus goes past it.
+    expect((await patch(goblinRow, dmAuth, { initiativeRoll: 20 })).body.participant).toMatchObject({ initiativeRoll: 20, initiative: 22 });
+
+    // Quests take initiative exactly as battles do.
+    await request(app).patch(e).set(dmAuth).send({ mode: 'QUEST' });
+    expect((await patch(heroRow, playerAuth, { initiativeRoll: 19 })).body.participant.initiative).toBe(19 + heroBonus);
+    await request(app).patch(e).set(dmAuth).send({ mode: 'BATTLE' });
+    await patch(heroRow, playerAuth, { initiativeRoll: 20 });
+
     // The DM can re-roll anyone, or clear a roll.
     expect((await patch(goblinRow, dmAuth, { initiativeRoll: 1 })).body.participant.initiative).toBe(3);
     expect((await patch(heroRow, dmAuth, { initiativeRoll: null })).body.participant).toMatchObject({ initiativeRoll: null, initiative: 0 });
@@ -1903,6 +1980,68 @@ describe('initiative', () => {
   });
 });
 
+describe('targets', () => {
+  itIfDb('are picked by the DM or the player on turn, shown to all, and go when the turn does', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('target');
+    const c = `/campaigns/${campaign.id}`;
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Archer');
+    const goblin = (await request(app).post(`${c}/monsters/from-library`).set(dmAuth).send({ key: 'goblin' })).body.monster;
+    const e = `/encounters/${(await request(app).post(`${c}/encounters`).set(dmAuth).send({ name: 'Ambush' })).body.encounter.id}`;
+    const add = async (body) => (await request(app).post(`${e}/participants`).set(dmAuth).send(body)).body.participant;
+    const hero = await add({ characterId: heroId, initiativeRoll: 20 });
+    const first = await add({ monsterId: goblin.id, initiativeRoll: 10 });
+    const second = await add({ monsterId: goblin.id, initiativeRoll: 1 });
+    const target = (auth, ...participantIds) => request(app).put(`${e}/targets`).set(auth).send({ participantIds });
+    const seen = async (auth) => (await request(app).get(e).set(auth)).body.encounter.targetParticipantIds;
+
+    // Before the battle only the DM can mark anyone.
+    expect((await target(playerAuth, first.id)).status).toBe(403);
+    expect((await target(dmAuth, first.id)).body.encounter.targetParticipantIds).toEqual([first.id]);
+    expect(await seen(playerAuth)).toEqual([first.id]);
+    expect((await target(dmAuth, first.id, 'nobody')).status).toBe(400);
+
+    // Beginning the battle clears them and puts the hero on turn: now the
+    // player can, and several at once is an area attack, kept in the order picked.
+    await request(app).patch(e).set(dmAuth).send({ status: 'ACTIVE' });
+    expect(await seen(dmAuth)).toEqual([]);
+    expect((await target(playerAuth, second.id, first.id, second.id)).status).toBe(200);
+    expect(await seen(dmAuth)).toEqual([second.id, first.id]);
+
+    // Removing a target unmarks it and leaves the rest.
+    await request(app).delete(`${e}/participants/${second.id}`).set(dmAuth);
+    expect(await seen(dmAuth)).toEqual([first.id]);
+
+    // The turn passing clears them, and the player is no longer on turn.
+    await request(app).post(`${e}/next-turn`).set(dmAuth);
+    expect(await seen(dmAuth)).toEqual([]);
+    expect((await target(playerAuth, first.id)).status).toBe(403);
+
+    // Whoever is on turn can't be a target, their own or as part of a group.
+    expect((await target(dmAuth, first.id)).status).toBe(400);
+    expect((await target(dmAuth, hero.id, first.id)).status).toBe(400);
+
+    // The goblin's turn: the DM marks the hero, and can clear it again.
+    expect((await target(dmAuth, hero.id)).body.encounter.targetParticipantIds).toEqual([hero.id]);
+    expect((await target(dmAuth)).body.encounter.targetParticipantIds).toEqual([]);
+  });
+});
+
+describe('area attack AC penalty', () => {
+  itIfDb('is a campaign setting the DM changes, 2 unless told otherwise', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('areapenalty');
+    const c = `/campaigns/${campaign.id}`;
+    expect(campaign.areaAttackAcPenalty).toBe(2);
+
+    expect((await request(app).patch(c).set(playerAuth).send({ areaAttackAcPenalty: 0 })).status).toBe(403);
+    expect((await request(app).patch(c).set(dmAuth).send({ areaAttackAcPenalty: 11 })).status).toBe(400);
+    expect((await request(app).patch(c).set(dmAuth).send({ areaAttackAcPenalty: -1 })).status).toBe(400);
+    expect((await request(app).patch(c).set(dmAuth).send({ areaAttackAcPenalty: 0 })).body.campaign.areaAttackAcPenalty).toBe(0);
+
+    // Players are told it too: their cards show the penalty on a marked target.
+    expect((await request(app).get(c).set(playerAuth)).body.campaign.areaAttackAcPenalty).toBe(0);
+  });
+});
+
 describe('number limits', () => {
   itIfDb('are enforced by the server, whatever a form sends', async () => {
     const { dmAuth, playerAuth, campaign } = await setupCampaign('limits');
@@ -1963,3 +2102,431 @@ describe('temporary hit points', () => {
     expect([now.currentHp, now.tempHp]).toEqual([0, 0]);
   });
 });
+
+describe('death saves', () => {
+  itIfDb('start at 0 HP, are settled by three of a kind, and end with healing', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('deathsaves');
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Fallen');
+    const ch = `/characters/${heroId}`;
+    const sheet = async () => (await request(app).get(ch).set(playerAuth)).body.character;
+    const hp = (auth, currentHp) => request(app).patch(ch).set(auth).send({ currentHp });
+    const save = (auth, body) => request(app).post(`${ch}/death-saves`).set(auth).send(body);
+    const max = (await sheet()).sheet.hp.max;
+    expect((await sheet()).deathSaves).toEqual({ state: 'UP', successes: 0, failures: 0 });
+
+    // No saves while standing, and a save is a d20.
+    expect((await save(playerAuth, { action: 'roll', roll: 12 })).status).toBe(400);
+    await hp(playerAuth, 0);
+    expect((await sheet()).deathSaves).toEqual({ state: 'DYING', successes: 0, failures: 0 });
+    expect((await save(playerAuth, { action: 'roll', roll: 21 })).status).toBe(400);
+
+    // 10 and up succeeds, below fails, and a 1 fails twice.
+    expect((await save(playerAuth, { action: 'roll', roll: 10 })).body.character.deathSaves).toEqual({ state: 'DYING', successes: 1, failures: 0 });
+    expect((await save(playerAuth, { action: 'roll', roll: 9 })).body.character.deathSaves).toEqual({ state: 'DYING', successes: 1, failures: 1 });
+
+    // Being hit while down is a failed save; healing clears the lot.
+    expect((await hp(dmAuth, -1)).body.character.deathSaves).toEqual({ state: 'DYING', successes: 1, failures: 2 });
+    expect((await hp(playerAuth, 3)).body.character.deathSaves).toEqual({ state: 'UP', successes: 0, failures: 0 });
+
+    // Three successes: stable, at 0 HP, with nothing left to roll.
+    await hp(playerAuth, 0);
+    for (const roll of [15, 11, 19]) await save(playerAuth, { action: 'roll', roll });
+    let now = await sheet();
+    expect([now.currentHp, now.deathSaves]).toEqual([0, { state: 'STABLE', successes: 0, failures: 0 }]);
+    expect((await save(playerAuth, { action: 'roll', roll: 12 })).status).toBe(400);
+
+    // Damage ends that; a 20 puts them back up with 1 HP.
+    expect((await hp(dmAuth, -1)).body.character.deathSaves).toEqual({ state: 'DYING', successes: 0, failures: 1 });
+    now = (await save(playerAuth, { action: 'roll', roll: 20 })).body.character;
+    expect([now.currentHp, now.deathSaves]).toEqual([1, { state: 'UP', successes: 0, failures: 0 }]);
+
+    // Someone else can steady them without a roll.
+    await hp(playerAuth, 0);
+    expect((await save(playerAuth, { action: 'stabilize' })).body.character.deathSaves.state).toBe('STABLE');
+
+    // The tallies are the DM's to set by hand; a 1 on top of two failures kills.
+    expect((await save(playerAuth, { action: 'set', successes: 0, failures: 0 })).status).toBe(403);
+    expect((await save(dmAuth, { action: 'set', successes: 2, failures: 2 })).body.character.deathSaves).toEqual({ state: 'DYING', successes: 2, failures: 2 });
+    expect((await save(playerAuth, { action: 'roll', roll: 1 })).body.character.deathSaves.state).toBe('DEAD');
+
+    // The dead can't be healed or roll; only the DM brings them back.
+    expect((await hp(playerAuth, max)).status).toBe(400);
+    expect((await save(playerAuth, { action: 'roll', roll: 20 })).status).toBe(400);
+    expect((await save(playerAuth, { action: 'revive' })).status).toBe(403);
+    now = (await save(dmAuth, { action: 'revive' })).body.character;
+    expect([now.currentHp, now.deathSaves]).toEqual([1, { state: 'UP', successes: 0, failures: 0 }]);
+  });
+
+  itIfDb('follow the character into an encounter, where one huge blow kills outright', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('deathsaves-enc');
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Doomed');
+    const ch = `/characters/${heroId}`;
+    const max = (await request(app).get(ch).set(playerAuth)).body.character.sheet.hp.max;
+    const e = `/encounters/${(await request(app).post(`/campaigns/${campaign.id}/encounters`).set(dmAuth).send({ name: 'Last Stand' })).body.encounter.id}`;
+    const row = (await request(app).post(`${e}/participants`).set(dmAuth).send({ characterId: heroId })).body.participant;
+    const strike = (currentHp) => request(app).patch(`${e}/participants/${row.id}`).set(dmAuth).send({ currentHp });
+    const combatant = async () => (await request(app).get(e).set(playerAuth)).body.encounter.participants[0];
+
+    // Temp HP that soaks the whole blow keeps them on their feet.
+    await request(app).patch(ch).set(playerAuth).send({ tempHp: 2 });
+    await strike(max - 2);
+    expect((await combatant()).characterCombatInfo.deathSaves.state).toBe('UP');
+
+    // Dropped by the DM in the tracker; the player's own save shows there.
+    await strike(1 - max); // max - 1 past zero: one short of killing outright
+    expect((await combatant()).characterCombatInfo.deathSaves).toEqual({ state: 'DYING', successes: 0, failures: 0 });
+    await request(app).post(`${ch}/death-saves`).set(playerAuth).send({ action: 'roll', roll: 4 });
+    expect((await combatant()).characterCombatInfo.deathSaves).toEqual({ state: 'DYING', successes: 0, failures: 1 });
+
+    // The party list carries it too.
+    const listed = (await request(app).get(`/campaigns/${campaign.id}/characters`).set(dmAuth)).body.characters.find((c) => c.id === heroId);
+    expect(listed.deathSaves.state).toBe('DYING');
+
+    // Healed, then hit for max HP more than they have left.
+    await strike(max);
+    await strike(-max);
+    const dmView = (await request(app).get(e).set(dmAuth)).body.encounter.participants[0];
+    expect([dmView.hidden, dmView.characterCombatInfo.deathSaves.state]).toEqual([true, 'DEAD']);
+    expect((await strike(5)).status).toBe(400);
+  });
+
+  itIfDb('hide the fallen from players, skip their turns, and let an ally with a reviving spell bring a character back', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('fallen');
+    const c = `/campaigns/${campaign.id}`;
+    const healerId = await buildCharacter(campaign.id, playerAuth, 'Healer');
+    const doomedId = await buildCharacter(campaign.id, playerAuth, 'Doomed');
+    const goblin = (await request(app).post(`${c}/monsters/from-library`).set(dmAuth).send({ key: 'goblin' })).body.monster;
+    const e = `/encounters/${(await request(app).post(`${c}/encounters`).set(dmAuth).send({ name: 'Crypt' })).body.encounter.id}`;
+    const add = async (body) => (await request(app).post(`${e}/participants`).set(dmAuth).send(body)).body.participant.id;
+    const healer = await add({ characterId: healerId, initiativeRoll: 20 });
+    const doomed = await add({ characterId: doomedId, initiativeRoll: 10 });
+    const gob = await add({ monsterId: goblin.id, initiativeRoll: 1 });
+    const setHp = (id, currentHp) => request(app).patch(`${e}/participants/${id}`).set(dmAuth).send({ currentHp });
+    const view = async (auth) => (await request(app).get(e).set(auth)).body.encounter;
+    const ids = (encounter) => encounter.participants.map((p) => p.id);
+    const revive = (auth, id) => request(app).post(`${e}/participants/${id}/revive`).set(auth);
+    const nextTurn = async () => (await request(app).post(`${e}/next-turn`).set(dmAuth)).body.encounter;
+
+    await request(app).patch(e).set(dmAuth).send({ status: 'ACTIVE' }); // the healer is on turn
+    await request(app).put(`${e}/targets`).set(dmAuth).send({ participantIds: [gob] });
+
+    // A monster at 0 HP is gone from the player's list, target mark and all; the DM keeps it.
+    await setHp(gob, 0);
+    let seen = await view(playerAuth);
+    expect([ids(seen), seen.targetParticipantIds, seen.fallen]).toEqual([[healer, doomed], [], []]);
+    seen = await view(dmAuth);
+    expect([ids(seen), seen.targetParticipantIds]).toEqual([[healer, doomed, gob], [gob]]);
+    expect(seen.participants.map((p) => p.hidden)).toEqual([false, false, true]);
+    expect((await request(app).put(`${e}/targets`).set(playerAuth).send({ participantIds: [gob] })).status).toBe(400);
+
+    // A dying character stays in view; a dead one is hidden, and named among the fallen.
+    await setHp(doomed, 0);
+    expect(ids(await view(playerAuth))).toEqual([healer, doomed]);
+    await request(app).post(`/characters/${doomedId}/death-saves`).set(dmAuth).send({ action: 'set', successes: 0, failures: 3 });
+    seen = await view(playerAuth);
+    expect([ids(seen), seen.fallen]).toEqual([[healer], [{ participantId: doomed, characterId: doomedId, name: 'Doomed' }]]);
+
+    // The dead join no other scene until they are revived.
+    const elsewhere = `/encounters/${(await request(app).post(`${c}/encounters`).set(dmAuth).send({ name: 'Elsewhere' })).body.encounter.id}`;
+    const join = () => request(app).post(`${elsewhere}/participants`).set(dmAuth).send({ characterId: doomedId });
+    expect((await join()).status).toBe(400);
+
+    // The fallen have no turn: with only the healer standing, the round rolls straight over.
+    seen = await nextTurn();
+    expect([seen.activeParticipantId, seen.currentRound]).toEqual([healer, 2]);
+
+    // Reviving takes a spell that brings back the dead, at a level the caster can use.
+    expect(seen.participants[0].characterCombatInfo.canRevive).toBe(false);
+    expect((await revive(playerAuth, doomed)).status).toBe(400);
+    const revivify = (await request(app).post(`${c}/spells/from-library`).set(dmAuth).send({ key: 'revivify' })).body.spell;
+    expect(revivify.revives).toBe(true);
+    await request(app).post(`/characters/${healerId}/spells`).set(dmAuth).send({ spellId: revivify.id });
+    expect((await revive(playerAuth, doomed)).status).toBe(400); // level 1 can't cast a level 3 spell
+    await request(app).patch(`/characters/${healerId}`).set(dmAuth).send({ level: 3 });
+    expect((await view(playerAuth)).participants[0].characterCombatInfo.canRevive).toBe(true);
+    expect((await revive(playerAuth, gob)).status).toBe(400); // monsters are healed, not revived
+
+    const revived = await revive(playerAuth, doomed);
+    expect([revived.status, revived.body.revivedWith]).toEqual([200, 'Revivify']);
+    expect([ids(revived.body.encounter), revived.body.encounter.fallen]).toEqual([[healer, doomed], []]);
+    const back = (await request(app).get(`/characters/${doomedId}`).set(playerAuth)).body.character;
+    expect([back.currentHp, back.deathSaves]).toEqual([1, { state: 'UP', successes: 0, failures: 0 }]);
+    expect((await revive(playerAuth, doomed)).status).toBe(400); // not dead any more
+    expect((await join()).status).toBe(201);
+
+    // Only on the reviver's own turn, and healing a monster brings it back into view.
+    expect((await nextTurn()).activeParticipantId).toBe(doomed);
+    await setHp(gob, 3);
+    expect(ids(await view(playerAuth))).toEqual([healer, doomed, gob]);
+    expect((await nextTurn()).activeParticipantId).toBe(gob);
+    expect((await revive(playerAuth, doomed)).status).toBe(403);
+  });
+});
+
+describe('silver and copper', () => {
+  itIfDb('are kept as separate coins, exchanged at fixed worth, given and rewarded', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('coins');
+    const c = `/campaigns/${campaign.id}`;
+    await request(app).patch(c).set(dmAuth).send({ startingGold: 5 });
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Purse');
+    const friendId = await buildCharacter(campaign.id, dmAuth, 'Friend');
+    const ch = `/characters/${heroId}`;
+    const purse = async (id = heroId, auth = playerAuth) => {
+      const { gold, silver, copper } = (await request(app).get(`/characters/${id}`).set(auth)).body.character;
+      return [gold, silver, copper];
+    };
+    const money = (body) => request(app).post(`${ch}/gold`).set(playerAuth).send(body);
+    const exchange = (body) => request(app).post(`${ch}/gold/exchange`).set(playerAuth).send(body);
+
+    expect(await purse()).toEqual([5, 0, 0]);
+
+    // Each coin has its own balance; an amount with no coin named is gold.
+    expect((await money({ amount: 7, currency: 'SILVER', reason: 'Sold a pelt' })).status).toBe(201);
+    expect((await money({ amount: 3, currency: 'COPPER' })).body.copper).toBe(3);
+    expect((await money({ amount: 1 })).body.gold).toBe(6);
+    expect(await purse()).toEqual([6, 7, 3]);
+    expect((await money({ amount: 1, currency: 'PLATINUM' })).status).toBe(400);
+
+    // A spend the whole purse can't cover is refused and moves nothing.
+    const short = await money({ amount: -1000, currency: 'SILVER' });
+    expect(short.status).toBe(400);
+    expect(short.body.error).toMatch(/Not enough money/);
+    expect(await purse()).toEqual([6, 7, 3]);
+    expect((await request(app).patch(ch).set(dmAuth).send({ silver: 99 })).status).toBe(400);
+
+    // 1 gold = 10 silver = 100 copper.
+    expect((await exchange({ from: 'GOLD', to: 'SILVER', amount: 1 })).body.received).toBe(10);
+    expect(await purse()).toEqual([5, 17, 3]);
+    expect((await exchange({ from: 'GOLD', to: 'COPPER', amount: 1 })).body.received).toBe(100);
+    expect((await exchange({ from: 'SILVER', to: 'COPPER', amount: 1 })).body.received).toBe(10);
+    expect(await purse()).toEqual([4, 16, 113]);
+    expect((await exchange({ from: 'COPPER', to: 'SILVER', amount: 20 })).body.received).toBe(2);
+    expect((await exchange({ from: 'SILVER', to: 'GOLD', amount: 10 })).body.received).toBe(1);
+    expect((await exchange({ from: 'COPPER', to: 'SILVER', amount: 90 })).body.received).toBe(9);
+    expect(await purse()).toEqual([5, 17, 3]);
+
+    // It has to come to whole coins, be affordable, and be between two different coins.
+    const uneven = await exchange({ from: 'SILVER', to: 'GOLD', amount: 5 });
+    expect(uneven.status).toBe(400);
+    expect(uneven.body.error).toMatch(/multiples of 10/);
+    expect((await exchange({ from: 'COPPER', to: 'SILVER', amount: 1 })).status).toBe(400);
+    expect((await exchange({ from: 'COPPER', to: 'GOLD', amount: 50 })).body.error).toMatch(/multiples of 100/);
+    expect((await exchange({ from: 'SILVER', to: 'COPPER', amount: 18 })).status).toBe(400);
+    expect((await exchange({ from: 'GOLD', to: 'GOLD', amount: 1 })).status).toBe(400);
+    expect((await request(app).post(`/characters/${friendId}/gold/exchange`).set(playerAuth).send({ from: 'GOLD', to: 'SILVER', amount: 1 })).status).toBe(403);
+    expect(await purse()).toEqual([5, 17, 3]);
+
+    // The ledger says which coin every entry is in.
+    const ledger = (await request(app).get(`${ch}/gold`).set(playerAuth)).body;
+    expect([ledger.gold, ledger.silver, ledger.copper]).toEqual([5, 17, 3]);
+    expect(ledger.transactions[0]).toMatchObject({ currency: 'SILVER', amount: 9, balanceAfter: 17, reason: 'Exchanged from 90 copper' });
+    expect(ledger.transactions.find((t) => t.reason === 'Sold a pelt')).toMatchObject({ currency: 'SILVER', amount: 7, balanceAfter: 7 });
+
+    // Giving and rewards work per coin.
+    expect((await request(app).post(`${ch}/give`).set(playerAuth).send({ kind: 'gold', currency: 'SILVER', amount: 3, toCharacterId: friendId })).status).toBe(200);
+    expect((await request(app).post(`${ch}/give`).set(playerAuth).send({ kind: 'gold', currency: 'COPPER', amount: 5000, toCharacterId: friendId })).status).toBe(400);
+    expect(await purse()).toEqual([5, 14, 3]);
+    expect(await purse(friendId, dmAuth)).toEqual([5, 3, 0]);
+
+    const e = `/encounters/${(await request(app).post(`${c}/encounters`).set(dmAuth).send({ name: 'Loose change' })).body.encounter.id}`;
+    await request(app).post(`${e}/participants`).set(dmAuth).send({ characterId: heroId });
+    await request(app).post(`${e}/participants`).set(dmAuth).send({ characterId: friendId });
+    const reward = (await request(app).post(`${e}/rewards`).set(dmAuth).send({ type: 'GOLD', gold: 9, currency: 'COPPER' })).body.reward;
+    expect(reward).toMatchObject({ gold: 9, currency: 'COPPER' });
+    await request(app).post(`${e}/rewards/${reward.id}/award`).set(dmAuth).send({ split: true });
+    const split = [(await purse())[2] - 3, (await purse(friendId, dmAuth))[2]].sort();
+    expect(split).toEqual([4, 5]); // 9 copper between two
+
+    // Another player still sees none of it.
+    const outsiderView = (await request(app).get(`/characters/${friendId}`).set(playerAuth)).body.character;
+    expect([outsiderView.gold, outsiderView.silver, outsiderView.copper]).toEqual([null, null, null]);
+  });
+});
+
+describe('paying with change', () => {
+  itIfDb('a spend or a gift is paid from the whole purse: bigger coins are broken, smaller ones counted out', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('change');
+    await request(app).patch(`/campaigns/${campaign.id}`).set(dmAuth).send({ startingGold: 5 });
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Spender');
+    const friendId = await buildCharacter(campaign.id, dmAuth, 'Friend');
+    const ch = `/characters/${heroId}`;
+    const purse = async (id = heroId, auth = playerAuth) => {
+      const { gold, silver, copper } = (await request(app).get(`/characters/${id}`).set(auth)).body.character;
+      return [gold, silver, copper];
+    };
+    const money = (body) => request(app).post(`${ch}/gold`).set(playerAuth).send(body);
+    const newest = async (count) =>
+      (await request(app).get(`${ch}/gold`).set(playerAuth)).body.transactions.slice(0, count).map((t) => [t.currency, t.amount, t.balanceAfter, t.reason]);
+
+    // 3 silver from a purse of 5 gold: one gold is broken, 7 silver comes back.
+    const boots = await money({ amount: -3, currency: 'SILVER', reason: 'New boots' });
+    expect(boots.status).toBe(201);
+    expect([boots.body.gold, boots.body.silver, boots.body.copper]).toEqual([4, 7, 0]);
+    expect(await purse()).toEqual([4, 7, 0]);
+    expect((await newest(2)).sort()).toEqual([
+      ['GOLD', -1, 4, 'New boots (paid 3 silver, with change)'],
+      ['SILVER', 7, 7, 'New boots (paid 3 silver, with change)'],
+    ]);
+
+    // 5 copper: the nearest bigger coin is a silver, so that is what breaks.
+    expect((await money({ amount: -5, currency: 'COPPER' })).status).toBe(201);
+    expect(await purse()).toEqual([4, 6, 5]);
+
+    // Enough of the coin named: nothing else moves, and the entry reads as usual.
+    await money({ amount: -2, reason: 'Horse feed' });
+    expect(await purse()).toEqual([2, 6, 5]);
+    expect((await newest(1))[0]).toEqual(['GOLD', -2, 2, 'Horse feed']);
+
+    // More than the whole purse is worth (2.65 gold): refused, nothing moves.
+    const tooMuch = await money({ amount: -3 });
+    expect(tooMuch.status).toBe(400);
+    expect(tooMuch.body.error).toMatch(/Not enough money/);
+    expect(tooMuch.body.error).toMatch(/2\.65 gold/);
+    expect(await purse()).toEqual([2, 6, 5]);
+
+    // No bigger coin to break: smaller ones are counted out, biggest first.
+    await money({ amount: -2 });
+    await money({ amount: 40, currency: 'COPPER' });
+    expect(await purse()).toEqual([0, 6, 45]);
+    expect((await money({ amount: -1, reason: 'Toll' })).status).toBe(201);
+    expect(await purse()).toEqual([0, 0, 5]);
+
+    // Giving works the same way for the giver; the recipient gets the coins named.
+    await money({ amount: 1 });
+    expect((await request(app).post(`${ch}/give`).set(playerAuth).send({ kind: 'gold', currency: 'SILVER', amount: 4, toCharacterId: friendId })).status).toBe(200);
+    expect(await purse()).toEqual([0, 6, 5]);
+    expect(await purse(friendId, dmAuth)).toEqual([5, 4, 0]);
+    const beyond = await request(app).post(`${ch}/give`).set(playerAuth).send({ kind: 'gold', amount: 1, toCharacterId: friendId });
+    expect(beyond.status).toBe(400);
+    expect(beyond.body.error).toMatch(/Not enough money/);
+
+    // Exchanging is the exception: it moves exactly the coins named.
+    expect((await request(app).post(`${ch}/gold/exchange`).set(playerAuth).send({ from: 'SILVER', to: 'COPPER', amount: 7 })).status).toBe(400);
+    expect(await purse()).toEqual([0, 6, 5]);
+  });
+});
+
+describe('trade', () => {
+  itIfDb('changes gold and cash with an NPC and sells wares, in a quest in progress only', async () => {
+    const { dmAuth, playerAuth, campaign } = await setupCampaign('trade');
+    const c = `/campaigns/${campaign.id}`;
+    const heroId = await buildCharacter(campaign.id, playerAuth, 'Aria');
+    const post = (path, body, auth = dmAuth) => request(app).post(path).set(auth).send(body);
+
+    // An NPC's rate has two sides, and only the DM sets it.
+    expect((await post(`${c}/npcs`, { name: 'Half', exchangeGold: 2 })).status).toBe(400);
+    const changer = (await post(`${c}/npcs`, { name: 'Vex', exchangeGold: 2, exchangeCash: 15 })).body.npc;
+    expect(changer).toMatchObject({ exchangeGold: 2, exchangeCash: 15 });
+    const baker = (await post(`${c}/npcs`, { name: 'Baker' })).body.npc;
+    const elsewhere = (await post(`${c}/npcs`, { name: 'Hermit' })).body.npc;
+    const patchNpc = (id, body) => request(app).patch(`${c}/npcs/${id}`).set(dmAuth).send(body);
+    expect((await patchNpc(baker.id, { exchangeCash: 3 })).status).toBe(400);
+
+    // Wares come from the campaign pools and belong to one seller.
+    const bread = (await post(`${c}/items`, { name: 'Bread' })).body.item;
+    const sword = (await post(`${c}/weapons/from-library`, { key: 'longsword' })).body.weapon;
+    const quest = (await post(`${c}/encounters`, { name: 'Market Day', mode: 'QUEST' })).body.encounter;
+    const e = `/encounters/${quest.id}`;
+    expect((await post(`${c}/wares`, { npcId: baker.id, itemId: bread.id, price: 3, currency: 'SILVER' }, playerAuth)).status).toBe(403);
+    expect((await post(`${c}/wares`, { itemId: bread.id, price: 3 })).status).toBe(400); // no seller
+    expect((await post(`${c}/wares`, { npcId: baker.id, encounterId: quest.id, itemId: bread.id, price: 3 })).status).toBe(400); // two sellers
+    expect((await post(`${c}/wares`, { npcId: baker.id, itemId: bread.id, weaponId: sword.id, price: 3 })).status).toBe(400); // two things
+    expect((await post(`${c}/wares`, { npcId: baker.id, itemId: 'nope', price: 3 })).status).toBe(400);
+    const loaf = (await post(`${c}/wares`, { npcId: baker.id, itemId: bread.id, price: 3, currency: 'SILVER', stock: 2 })).body.ware;
+    const blade = (await post(`${c}/wares`, { encounterId: quest.id, weaponId: sword.id, price: 40, currency: 'CASH' })).body.ware;
+    const relic = (await post(`${c}/wares`, { npcId: elsewhere.id, itemId: bread.id, price: 1 })).body.ware;
+    expect(loaf).toMatchObject({ stock: 2, level: 1, item: { name: 'Bread' } });
+    expect(blade.stock).toBeNull();
+    const npcList = (await request(app).get(`${c}/npcs`).set(dmAuth)).body.npcs;
+    expect(npcList.find((n) => n.id === baker.id).wares).toHaveLength(1);
+
+    await post(`${e}/participants`, { characterId: heroId });
+    await post(`${e}/participants`, { npcId: changer.id });
+    const bakerRow = (await post(`${e}/participants`, { npcId: baker.id })).body.participant;
+    await post(`/characters/${heroId}/gold`, { amount: 10 });
+
+    // Players see the rate and everything for sale in the scene.
+    const seen = (await request(app).get(e).set(playerAuth)).body.encounter;
+    const seenNpc = (name) => seen.participants.find((p) => p.npc?.name === name).npc;
+    expect(seenNpc('Vex')).toMatchObject({ exchangeGold: 2, exchangeCash: 15 });
+    expect(seenNpc('Baker').wares.map((w) => [w.item.name, w.price, w.currency, w.stock])).toEqual([['Bread', 3, 'SILVER', 2]]);
+    expect(seen.wares.map((w) => w.weapon.name)).toEqual(['Longsword']);
+    expect(seenNpc('Baker').dmNotes).toBeUndefined();
+
+    const exchange = (body, auth = playerAuth) => post(`${e}/exchange`, { characterId: heroId, npcId: changer.id, ...body }, auth);
+    const buy = (wareId, body = {}, auth = playerAuth) => post(`${e}/wares/${wareId}/buy`, { characterId: heroId, ...body }, auth);
+    const purse = async () => {
+      const { gold, silver, copper, cash } = (await request(app).get(`/characters/${heroId}`).set(playerAuth)).body.character;
+      return { gold, silver, copper, cash };
+    };
+
+    // Nothing is traded before the quest begins, and never in a battle.
+    expect((await exchange({ from: 'GOLD', amount: 2 })).status).toBe(400);
+    expect((await buy(loaf.id)).status).toBe(400);
+    await request(app).patch(e).set(dmAuth).send({ status: 'ACTIVE', mode: 'BATTLE' });
+    expect((await exchange({ from: 'GOLD', amount: 2 })).status).toBe(400);
+    expect((await buy(loaf.id)).status).toBe(400);
+    await request(app).patch(e).set(dmAuth).send({ mode: 'QUEST' });
+
+    // Gold and cash only, in whole multiples of the rate, either way.
+    expect((await exchange({ from: 'SILVER', amount: 10 })).status).toBe(400);
+    expect((await exchange({ from: 'GOLD', amount: 3 })).status).toBe(400);
+    expect((await exchange({ from: 'GOLD', amount: 12 })).status).toBe(400); // only has 10
+    expect((await exchange({ from: 'GOLD', amount: 2, npcId: baker.id })).status).toBe(400); // not a money changer
+    const changed = await exchange({ from: 'GOLD', amount: 6 });
+    expect(changed.status).toBe(201);
+    expect(changed.body).toMatchObject({ received: 45, currency: 'CASH' });
+    expect(await purse()).toEqual({ gold: 4, silver: 0, copper: 0, cash: 45 });
+    expect((await exchange({ from: 'CASH', amount: 20 })).status).toBe(400);
+    expect((await exchange({ from: 'CASH', amount: 15 })).body.received).toBe(2);
+    expect(await purse()).toEqual({ gold: 6, silver: 0, copper: 0, cash: 30 });
+    const ledger = (await request(app).get(`/characters/${heroId}/gold`).set(playerAuth)).body.transactions;
+    expect(ledger.slice(0, 2).map((t) => [t.currency, t.amount, t.reason]).sort()).toEqual([
+      ['CASH', -15, 'Changed with Vex for 2 gold'],
+      ['GOLD', 2, 'Changed with Vex from $15'],
+    ]);
+
+    // Buying pays the price (coins make change), hands the thing over and uses up stock.
+    expect((await buy(relic.id)).status).toBe(400); // that NPC is not here
+    expect((await buy(blade.id)).status).toBe(400); // $40, has $30
+    expect((await buy(loaf.id, { quantity: 3 })).status).toBe(400); // only 2 left
+    const bought = await buy(loaf.id, { quantity: 2 });
+    expect(bought.status).toBe(201);
+    expect(await purse()).toEqual({ gold: 5, silver: 4, copper: 0, cash: 30 });
+    expect((await buy(loaf.id)).body.error).toContain('sold out');
+    await exchange({ from: 'GOLD', amount: 2 });
+    expect((await buy(blade.id)).status).toBe(201);
+    expect(await purse()).toEqual({ gold: 3, silver: 4, copper: 0, cash: 5 });
+    const sheet = (await request(app).get(`/characters/${heroId}`).set(playerAuth)).body.character;
+    expect(sheet.inventoryItems.map((i) => [i.item.name, i.quantity])).toEqual([['Bread', 2]]);
+    expect(sheet.weapons.map((w) => w.weapon.name)).toContain('Longsword');
+
+    // A player trades for their own character only; an NPC who is down sells nothing.
+    const other = await request(app).post('/auth/register').send({ email: uniqueEmail('trade-other'), password: 'password123', displayName: 'Other' });
+    cleanupUserIds.push(other.body.user.id);
+    const otherAuth = { Authorization: `Bearer ${other.body.token}` };
+    await request(app).post(`/campaigns/join/${campaign.inviteCode}`).set(otherAuth);
+    const otherId = await buildCharacter(campaign.id, otherAuth, 'Bo');
+    await post(`${e}/participants`, { characterId: otherId });
+    expect((await buy(blade.id, {}, otherAuth)).status).toBe(403);
+    expect((await exchange({ from: 'GOLD', amount: 2 }, dmAuth)).status).toBe(201); // the DM can, for anyone
+
+    // The DM can reprice and restock a ware; nobody else can.
+    const patchWare = (auth, body) => request(app).patch(`${c}/wares/${loaf.id}`).set(auth).send(body);
+    expect((await patchWare(playerAuth, { price: 1 })).status).toBe(403);
+    expect((await patchWare(dmAuth, { price: 0 })).status).toBe(400);
+    expect((await patchWare(dmAuth, { stock: 5, price: 1, currency: 'COPPER' })).body.ware).toMatchObject({ stock: 5, price: 1, currency: 'COPPER', item: { name: 'Bread' } });
+    expect((await patchWare(dmAuth, { stock: null })).body.ware).toMatchObject({ stock: null, price: 1 });
+    expect((await buy(loaf.id)).status).toBe(201);
+    expect(await purse()).toEqual({ gold: 1, silver: 3, copper: 9, cash: 20 });
+    await patchNpc(baker.id, { maxHp: 5 });
+    await request(app).delete(`${e}/participants/${bakerRow.id}`).set(dmAuth);
+    const downRow = (await post(`${e}/participants`, { npcId: baker.id })).body.participant;
+    await request(app).patch(`${e}/participants/${downRow.id}`).set(dmAuth).send({ currentHp: 0 });
+    expect((await buy(loaf.id)).status).toBe(400);
+
+    expect((await request(app).delete(`${c}/wares/${blade.id}`).set(playerAuth)).status).toBe(403);
+    expect((await request(app).delete(`${c}/wares/${blade.id}`).set(dmAuth)).status).toBe(204);
+    expect((await request(app).get(e).set(playerAuth)).body.encounter.wares).toEqual([]);
+  });
+});

backend/src/routes/campaigns.routes.js

@@ -7,6 +7,8 @@ const { generateInviteCode } = require('../utils/inviteCode');
 const { computeCharacterSheet, MAX_DAMAGE_SCALING, MAX_GEAR_LEVEL } = require('../game/calculations');
 const { WEAPON_LIBRARY, SPELL_LIBRARY, MONSTER_LIBRARY } = require('../game/data/library');
 const { visitedLocationIds } = require('../utils/locations');
+const { deathSaveInfo } = require('../utils/hp');
+const { CURRENCIES } = require('../utils/grants');
 
 const router = express.Router();
 
@@ -24,6 +26,7 @@ function campaignSummary(campaign, role) {
     startingSpellCount: campaign.startingSpellCount,
     skipMotivationRoll: campaign.skipMotivationRoll,
     showMonsterHp: campaign.showMonsterHp,
+    areaAttackAcPenalty: campaign.areaAttackAcPenalty,
     ownerId: campaign.ownerId,
     archivedAt: campaign.archivedAt,
     role,
@@ -53,6 +56,7 @@ const createCampaignSchema = z.object({
   startingSpellCount: z.number().int().min(0).max(50).optional(),
   skipMotivationRoll: z.boolean().optional(),
   showMonsterHp: z.boolean().optional(),
+  areaAttackAcPenalty: z.number().int().min(0).max(10).optional(),
 });
 
 // POST /campaigns — create, creator becomes DM/owner
@@ -194,7 +198,11 @@ function characterSummary(character) {
     buildStage: character.buildStage,
     currentHp: character.currentHp,
     tempHp: character.tempHp,
+    deathSaves: deathSaveInfo(character),
     gold: character.gold,
+    silver: character.silver,
+    copper: character.copper,
+    cash: character.cash,
     maxHp: character.buildStage === 'COMPLETE' ? sheet.hp.max : null,
     armorClass: character.buildStage === 'COMPLETE' ? sheet.armorClass : null,
     currentLocationId: character.currentLocationId,
@@ -219,7 +227,7 @@ router.get('/:id/characters', requireCampaignMember(), async (req, res, next) =>
       characters: summaries.map((c) => {
         if (c.userId === req.user.id) return c;
         const knowsPlace = c.currentLocationId && visited.has(c.currentLocationId);
-        return { ...c, gold: null, ...(knowsPlace ? {} : { currentLocationId: null, currentLocationName: null }) };
+        return { ...c, gold: null, silver: null, copper: null, cash: null, ...(knowsPlace ? {} : { currentLocationId: null, currentLocationName: null }) };
       }),
     });
   } catch (err) {
@@ -399,6 +407,7 @@ const spellSchema = z.object({
   description: z.string().max(4000).optional().nullable(),
   damageDice: z.string().max(20).optional().nullable(),
   isStartingOption: z.boolean().optional(),
+  revives: z.boolean().optional(), // brings back the dead
 });
 
 router.post('/:id/spells', requireCampaignMember(), requireDM(), async (req, res, next) => {
@@ -518,7 +527,7 @@ const monsterSchema = z.object({
   wisScore: z.number().int().min(1).max(30).optional(),
   chaScore: z.number().int().min(1).max(30).optional(),
   attackBonus: z.number().int().min(-20).max(50).optional(),
-  damageDice: z.string().max(20).optional().nullable(),
+  damageDice: z.string().max(60).optional().nullable(), // may name its type: "1d6+2 necrotic"
   challengeRating: z.string().max(10).optional().nullable(),
   specialTrait: z.string().max(500).optional().nullable(),
   notes: z.string().max(2000).optional().nullable(),
@@ -637,7 +646,11 @@ router.put('/:id/encounters/order', requireCampaignMember(), requireDM(), async
 
 router.get('/:id/npcs', requireCampaignMember(), requireDM(), async (req, res, next) => {
   try {
-    const npcs = await prisma.npc.findMany({ where: { campaignId: req.campaign.id }, orderBy: { name: 'asc' } });
+    const npcs = await prisma.npc.findMany({
+      where: { campaignId: req.campaign.id },
+      include: { wares: { include: WARE_INCLUDE, orderBy: { createdAt: 'asc' } } },
+      orderBy: { name: 'asc' },
+    });
     res.json({ npcs });
   } catch (err) {
     next(err);
@@ -654,12 +667,31 @@ const npcSchema = z.object({
   maxHp: z.number().int().min(1).max(100000).optional().nullable(),
   attackBonus: z.number().int().min(-20).max(50).optional().nullable(),
   damageDice: z.string().max(20).optional().nullable(),
+  // The money changer's rate: exchangeGold gold for exchangeCash cash. Both
+  // null for an NPC who does not change money.
+  exchangeGold: z.number().int().min(1).max(1000000).optional().nullable(),
+  exchangeCash: z.number().int().min(1).max(1000000).optional().nullable(),
 });
 
+// A rate has two sides: both are given, or both are cleared.
+function halfARate(data) {
+  const sides = [data.exchangeGold, data.exchangeCash];
+  return sides.some((side) => side === undefined) !== sides.every((side) => side === undefined) || (sides[0] === null) !== (sides[1] === null);
+}
+const HALF_A_RATE = 'An exchange rate needs both sides: so much gold for so much cash.';
+
+const WARE_INCLUDE = { weapon: true, item: true };
+
+// Open encounter pages refetch: what is for sale in a scene just changed.
+function emitTradeChanged(req) {
+  req.app.get('io').to(`campaign:${req.campaign.id}`).emit('encounter:participant-updated', {});
+}
+
 router.post('/:id/npcs', requireCampaignMember(), requireDM(), async (req, res, next) => {
   try {
     const parsed = npcSchema.safeParse(req.body);
     if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    if (halfARate(parsed.data)) return res.status(400).json({ error: HALF_A_RATE });
     const npc = await prisma.npc.create({ data: { ...parsed.data, campaignId: req.campaign.id } });
     res.status(201).json({ npc });
   } catch (err) {
@@ -671,8 +703,10 @@ router.patch('/:id/npcs/:npcId', requireCampaignMember(), requireDM(), async (re
   try {
     const parsed = npcSchema.partial().safeParse(req.body);
     if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    if (halfARate(parsed.data)) return res.status(400).json({ error: HALF_A_RATE });
     const npc = await updatePoolEntry('npc', req.params.npcId, req.campaign.id, parsed.data);
     if (!npc) return res.status(404).json({ error: 'NPC not found in this campaign' });
+    emitTradeChanged(req);
     res.json({ npc });
   } catch (err) {
     next(err);
@@ -772,6 +806,83 @@ router.delete('/:id/locations/:locationId', requireCampaignMember(), requireDM()
   }
 });
 
+// ---------------------------------------------------------------------------
+// Wares — weapons and items for sale, by an NPC or at an encounter itself.
+// Only the DM sets them up. Players see them, and buy, on the encounter page
+// (encounters.routes.js); an NPC's wares go wherever the NPC does.
+// ---------------------------------------------------------------------------
+
+const wareSchema = z
+  .object({
+    npcId: z.string().optional(),
+    encounterId: z.string().optional(),
+    weaponId: z.string().optional(),
+    itemId: z.string().optional(),
+    price: z.number().int().min(1).max(1000000),
+    currency: z.enum(CURRENCIES).default('GOLD'),
+    level: z.number().int().min(1).max(MAX_GEAR_LEVEL).optional(),
+    stock: z.number().int().min(0).max(9999).optional().nullable(), // null: no limit
+  })
+  .refine((data) => Boolean(data.npcId) !== Boolean(data.encounterId), { message: 'Say who sells it: an NPC or an encounter, not both' })
+  .refine((data) => Boolean(data.weaponId) !== Boolean(data.itemId), { message: 'Pick one weapon or one item to sell' });
+
+router.post('/:id/wares', requireCampaignMember(), requireDM(), async (req, res, next) => {
+  try {
+    const parsed = wareSchema.safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const data = parsed.data;
+    const inCampaign = async (model, id) => (id ? prisma[model].findFirst({ where: { id, campaignId: req.campaign.id } }) : null);
+
+    const seller = (await inCampaign('npc', data.npcId)) || (await inCampaign('encounter', data.encounterId));
+    if (!seller) return res.status(400).json({ error: 'That seller is not part of this campaign.' });
+    const entry = (await inCampaign('weapon', data.weaponId)) || (await inCampaign('item', data.itemId));
+    if (!entry) return res.status(400).json({ error: `That ${data.weaponId ? 'weapon' : 'item'} is not part of this campaign.` });
+    const level = data.level ?? entry.minLevel;
+    if (level < entry.minLevel) {
+      return res.status(400).json({ error: `${entry.name} starts at level ${entry.minLevel} and can't go below it.` });
+    }
+
+    const ware = await prisma.saleOffer.create({ data: { ...data, level, campaignId: req.campaign.id }, include: WARE_INCLUDE });
+    emitTradeChanged(req);
+    res.status(201).json({ ware });
+  } catch (err) {
+    next(err);
+  }
+});
+
+// The price and what is left can change; what is sold, and by whom, cannot.
+const patchWareSchema = z.object({
+  price: z.number().int().min(1).max(1000000).optional(),
+  currency: z.enum(CURRENCIES).optional(),
+  stock: z.number().int().min(0).max(9999).nullable().optional(),
+});
+
+router.patch('/:id/wares/:wareId', requireCampaignMember(), requireDM(), async (req, res, next) => {
+  try {
+    const parsed = patchWareSchema.safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    if (!(await updatePoolEntry('saleOffer', req.params.wareId, req.campaign.id, parsed.data))) {
+      return res.status(404).json({ error: 'Nothing like that is for sale in this campaign' });
+    }
+    emitTradeChanged(req);
+    res.json({ ware: await prisma.saleOffer.findUnique({ where: { id: req.params.wareId }, include: WARE_INCLUDE }) });
+  } catch (err) {
+    next(err);
+  }
+});
+
+router.delete('/:id/wares/:wareId', requireCampaignMember(), requireDM(), async (req, res, next) => {
+  try {
+    if (!(await deletePoolEntry('saleOffer', req.params.wareId, req.campaign.id))) {
+      return res.status(404).json({ error: 'Nothing like that is for sale in this campaign' });
+    }
+    emitTradeChanged(req);
+    res.status(204).end();
+  } catch (err) {
+    next(err);
+  }
+});
+
 // ---------------------------------------------------------------------------
 // Default content library — static SRD-style weapons/spells/monsters any
 // campaign can pull from, instead of the DM hand-typing everything. See

backend/src/routes/characters.routes.js

@@ -29,9 +29,9 @@ const {
 } = require('../game/buildFlow');
 const characterOptions = require('../game/data/characterOptions');
 const { SKILLS } = require('../game/data/skills');
-const { InsufficientGoldError, adjustGold, giveGear } = require('../utils/grants');
+const { CURRENCIES, COINS, COIN_VALUE, COIN_COLUMN, InsufficientGoldError, adjustGold, spendCoins, worthInGold, giveGear } = require('../utils/grants');
 const { recordVisits } = require('../utils/locations');
-const { absorbDamage } = require('../utils/hp');
+const { absorbDamage, NO_DEATH_SAVES, lifeState, deathSaveInfo, settleDeathSaves, changeHp, rollDeathSave } = require('../utils/hp');
 
 const router = express.Router();
 
@@ -85,6 +85,7 @@ function serializeCharacter(character, isOwner, isDM = true) {
     },
     currentHp: character.currentHp,
     tempHp: character.tempHp,
+    deathSaves: deathSaveInfo(character),
     armorBonus: character.armorBonus,
     specialAbilities: character.specialAbilities,
     background: character.background,
@@ -94,6 +95,9 @@ function serializeCharacter(character, isOwner, isDM = true) {
     currentLocationId: restricted ? null : character.currentLocationId,
     currentLocation: restricted ? null : character.currentLocation || null,
     gold: restricted ? null : character.gold,
+    silver: restricted ? null : character.silver,
+    copper: restricted ? null : character.copper,
+    cash: restricted ? null : character.cash,
     restricted,
     buildStage: character.buildStage,
     buildState: character.buildStage === 'COMPLETE' ? null : character.buildState,
@@ -170,8 +174,8 @@ function clamp(value, min, max) {
 
 router.patch('/:id', requireCharacterAccess({ write: true }), async (req, res, next) => {
   try {
-    if (req.body && req.body.gold !== undefined) {
-      return res.status(400).json({ error: 'Gold changes go through the money tracker.' });
+    if (req.body && Object.values(COIN_COLUMN).some((coin) => req.body[coin] !== undefined)) {
+      return res.status(400).json({ error: 'Gold, silver, copper and cash changes go through the money tracker.' });
     }
     const parsed = patchCharacterSchema.safeParse(req.body);
     if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
@@ -182,18 +186,28 @@ router.patch('/:id', requireCharacterAccess({ write: true }), async (req, res, n
 
     // Damage is soaked by temp HP before it reaches real HP — unless this
     // same request sets temp HP outright.
-    if (parsed.data.currentHp !== undefined && parsed.data.tempHp === undefined) {
+    const settingHp = parsed.data.currentHp !== undefined;
+    const settingTempHp = parsed.data.tempHp !== undefined;
+    if (req.character.buildStage === 'COMPLETE' && (settingHp || parsed.data.level !== undefined)) {
+      // Current HP stays within 0..max, including when a level change moves max.
+      const maxHp = computeCharacterSheet({ ...req.character, ...parsed.data }).hp.max;
+      if (!settingHp) {
+        parsed.data.currentHp = clamp(req.character.currentHp, 0, maxHp);
+      } else {
+        if (lifeState(req.character) === 'DEAD' && parsed.data.currentHp > 0) {
+          return res.status(400).json({ error: `${req.character.name} is dead. The DM has to revive them before they can be healed.` });
+        }
+        // Reaching 0, being hit while there, and being healed back up all
+        // move the death saves along with the HP.
+        const { tempHp, ...after } = changeHp(settingTempHp ? { ...req.character, tempHp: 0 } : req.character, parsed.data.currentHp, maxHp);
+        Object.assign(parsed.data, after, settingTempHp ? {} : { tempHp });
+      }
+    } else if (settingHp && !settingTempHp) {
       const after = absorbDamage(req.character.currentHp, req.character.tempHp, parsed.data.currentHp);
       parsed.data.currentHp = after.currentHp;
       if (after.tempHp !== req.character.tempHp) parsed.data.tempHp = after.tempHp;
     }
 
-    // Current HP stays within 0..max, including when a level change moves max.
-    if (req.character.buildStage === 'COMPLETE' && (parsed.data.currentHp !== undefined || parsed.data.level !== undefined)) {
-      const maxHp = computeCharacterSheet({ ...req.character, ...parsed.data }).hp.max;
-      parsed.data.currentHp = clamp(parsed.data.currentHp ?? req.character.currentHp, 0, maxHp);
-    }
-
     // privateNotes is for the owning player only — a DM editing someone
     // else's character (or another player, though write access already
     // blocks that) should never be able to set it through this route.
@@ -232,6 +246,61 @@ router.patch('/:id', requireCharacterAccess({ write: true }), async (req, res, n
   }
 });
 
+// ---------------------------------------------------------------------------
+// Death saves — what happens to a character at 0 HP (utils/hp.js)
+// ---------------------------------------------------------------------------
+
+const deathSaveTally = z.number().int().min(0).max(3);
+const deathSaveRoll = z.number().int().min(1, 'A death save is a d20: 1 to 20').max(20, 'A death save is a d20: 1 to 20');
+
+const deathSaveSchema = z.discriminatedUnion('action', [
+  // What the d20 showed; the server works out what it means.
+  z.object({ action: z.literal('roll'), roll: deathSaveRoll }),
+  // Steadied by someone else: a Medicine check, a healer's kit, a spell.
+  z.object({ action: z.literal('stabilize') }),
+  // The DM setting the tallies by hand: a critical hit's second failure, or
+  // undoing a mistake.
+  z.object({ action: z.literal('set'), successes: deathSaveTally, failures: deathSaveTally }),
+  // The DM bringing back the dead, at 1 HP.
+  z.object({ action: z.literal('revive') }),
+]);
+
+// The owning player rolls their own death saves and can be steadied; setting
+// the tallies by hand and raising the dead are the DM's.
+router.post('/:id/death-saves', requireCharacterAccess({ write: true }), async (req, res, next) => {
+  try {
+    const parsed = deathSaveSchema.safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const { character } = req;
+    if (character.buildStage !== 'COMPLETE') return res.status(400).json({ error: 'Character build is not finished yet.' });
+
+    const input = parsed.data;
+    const state = lifeState(character);
+    if ((input.action === 'set' || input.action === 'revive') && !req.isDM) {
+      return res.status(403).json({ error: 'Only the DM can do that.' });
+    }
+
+    let data;
+    if (input.action === 'roll' || input.action === 'stabilize') {
+      if (state !== 'DYING') return res.status(400).json({ error: `${character.name} is not dying, so there is no death save to make.` });
+      data = input.action === 'roll' ? rollDeathSave(character, input.roll) : { ...NO_DEATH_SAVES, stable: true };
+    } else if (input.action === 'set') {
+      if (state === 'UP') return res.status(400).json({ error: `${character.name} is not at 0 HP.` });
+      data = settleDeathSaves(input.successes, input.failures);
+    } else {
+      if (state !== 'DEAD') return res.status(400).json({ error: `${character.name} is not dead.` });
+      data = { currentHp: 1, ...NO_DEATH_SAVES };
+    }
+
+    await prisma.character.update({ where: { id: character.id }, data });
+    const full = await loadFullCharacter(character.id);
+    req.app.get('io').to(`campaign:${full.campaignId}`).emit('character:updated', { characterId: full.id });
+    res.json({ character: serializeCharacter(full, req.isOwner) });
+  } catch (err) {
+    next(err);
+  }
+});
+
 router.delete('/:id', requireCharacterAccess(), async (req, res, next) => {
   try {
     if (!req.isDM) return res.status(403).json({ error: 'DM only' });
@@ -355,6 +424,9 @@ router.post('/:id/copy', requireCharacterAccess(), async (req, res, next) => {
           speedOverride: source.speedOverride,
           specialAbilities: source.specialAbilities,
           gold: source.gold,
+          silver: source.silver,
+          copper: source.copper,
+          cash: source.cash,
           background: source.background,
           appearance: source.appearance,
           // Same privacy boundary as serializeCharacter: a DM copying a
@@ -370,10 +442,13 @@ router.post('/:id/copy', requireCharacterAccess(), async (req, res, next) => {
           },
           inventoryItems: { create: [...items.values()] },
           goldTransactions: {
-            create:
-              source.gold > 0
-                ? [{ amount: source.gold, balanceAfter: source.gold, reason: 'Carried over from another campaign', createdById: req.user.id }]
-                : [],
+            create: CURRENCIES.filter((currency) => source[COIN_COLUMN[currency]] > 0).map((currency) => ({
+              currency,
+              amount: source[COIN_COLUMN[currency]],
+              balanceAfter: source[COIN_COLUMN[currency]],
+              reason: 'Carried over from another campaign',
+              createdById: req.user.id,
+            })),
           },
           weapons: { create: [...weapons.values()] },
           spells: { create: [...spells.values()] },
@@ -837,6 +912,7 @@ router.get('/:id/quick-stats', requireCharacterAccess(), async (req, res, next)
         currentHp: character.currentHp,
         maxHp: sheet.hp.max,
         tempHp: character.tempHp,
+        deathSaves: deathSaveInfo(character),
         armorClass: sheet.armorClass,
         initiative: sheet.initiative,
         speed: sheet.speed,
@@ -857,6 +933,21 @@ router.get('/:id/quick-stats', requireCharacterAccess(), async (req, res, next)
 
 const GOLD_TRANSACTION_INCLUDE = { createdBy: { select: { displayName: true } } };
 
+// Which coin an amount is in; gold when none is given.
+const currencySchema = z.enum(CURRENCIES).default('GOLD');
+
+function coinName(currency) {
+  return currency.toLowerCase();
+}
+
+const PURSE_SELECT = { gold: true, silver: true, copper: true, cash: true };
+
+// For a payment the whole purse can't cover. Cash stands apart from the coins.
+function notEnoughMoney(character, amount, currency) {
+  if (currency === 'CASH') return `Not enough cash — ${character.name} has $${character.cash}, which doesn't cover $${amount}.`;
+  return `Not enough money — ${character.name} has ${character.gold} gold, ${character.silver} silver and ${character.copper} copper (worth ${worthInGold(character)} gold), which doesn't cover ${amount} ${coinName(currency)}.`;
+}
+
 router.get('/:id/gold', requireCharacterAccess(), async (req, res, next) => {
   try {
     if (!req.isDM && !req.isOwner) return res.status(403).json({ error: "Only the character's player and the DM can see its money" });
@@ -865,7 +956,7 @@ router.get('/:id/gold', requireCharacterAccess(), async (req, res, next) => {
       include: GOLD_TRANSACTION_INCLUDE,
       orderBy: [{ createdAt: 'desc' }, { id: 'desc' }],
     });
-    res.json({ gold: req.character.gold, transactions });
+    res.json({ gold: req.character.gold, silver: req.character.silver, copper: req.character.copper, cash: req.character.cash, transactions });
   } catch (err) {
     next(err);
   }
@@ -873,30 +964,76 @@ router.get('/:id/gold', requireCharacterAccess(), async (req, res, next) => {
 
 // amount is signed: positive = gained, negative = spent. The owning player
 // and the DM can both record entries; each one is stamped with who made it.
+// A spend is paid from the whole purse: if there aren't enough of the coin
+// named, bigger coins are broken (or smaller ones counted out) to cover it.
+// Cash is only ever paid in cash.
 router.post('/:id/gold', requireCharacterAccess({ write: true }), async (req, res, next) => {
   try {
     const parsed = z
       .object({
         amount: z.number().int().min(-1000000).max(1000000).refine((n) => n !== 0, 'Amount cannot be zero'),
+        currency: currencySchema,
         reason: z.string().trim().max(200).optional().nullable(),
       })
       .safeParse(req.body);
     if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
-    const { amount, reason } = parsed.data;
+    const { amount, currency, reason } = parsed.data;
 
-    let transaction;
+    let transactions;
     try {
       // Throwing inside the transaction rolls the balance change back.
-      transaction = await prisma.$transaction((tx) =>
-        adjustGold(tx, { characterId: req.character.id, amount, reason, userId: req.user.id, include: GOLD_TRANSACTION_INCLUDE })
-      );
+      transactions = await prisma.$transaction(async (tx) => {
+        const entry = { characterId: req.character.id, currency, reason, userId: req.user.id, include: GOLD_TRANSACTION_INCLUDE };
+        return amount > 0 ? [await adjustGold(tx, { ...entry, amount })] : spendCoins(tx, { ...entry, amount: -amount });
+      });
     } catch (err) {
       if (!(err instanceof InsufficientGoldError)) throw err;
-      return res.status(400).json({ error: `Not enough gold — the balance is ${req.character.gold}.` });
+      return res.status(400).json({ error: notEnoughMoney(req.character, -amount, currency) });
     }
 
     emitCharacterUpdated(req);
-    res.status(201).json({ gold: transaction.balanceAfter, transaction });
+    const purse = await prisma.character.findUnique({ where: { id: req.character.id }, select: PURSE_SELECT });
+    res.status(201).json({ ...purse, transaction: transactions[0], transactions });
+  } catch (err) {
+    next(err);
+  }
+});
+
+// Changes coins of one kind into another at their fixed worth (1 gold = 10
+// silver = 100 copper). `amount` is how many `from` coins to hand over; it has
+// to come to a whole number of `to` coins. Both sides go on the ledger. Unlike
+// a spend, this moves exactly the coins named: no change is made. Cash has no
+// worth in coins, so it can't be exchanged.
+router.post('/:id/gold/exchange', requireCharacterAccess({ write: true }), async (req, res, next) => {
+  try {
+    const parsed = z
+      .object({ from: z.enum(COINS), to: z.enum(COINS), amount: z.number().int().min(1).max(1000000) })
+      .refine((data) => data.from !== data.to, { message: 'Pick two different coins' })
+      .safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const { from, to, amount } = parsed.data;
+
+    const worth = amount * COIN_VALUE[from];
+    if (worth % COIN_VALUE[to] !== 0) {
+      const step = COIN_VALUE[to] / COIN_VALUE[from];
+      return res.status(400).json({ error: `${amount} ${coinName(from)} doesn't make a whole number of ${coinName(to)} — exchange in multiples of ${step}.` });
+    }
+    const received = worth / COIN_VALUE[to];
+
+    try {
+      await prisma.$transaction(async (tx) => {
+        const base = { characterId: req.character.id, userId: req.user.id };
+        await adjustGold(tx, { ...base, currency: from, amount: -amount, reason: `Exchanged for ${received} ${coinName(to)}` });
+        await adjustGold(tx, { ...base, currency: to, amount: received, reason: `Exchanged from ${amount} ${coinName(from)}` });
+      });
+    } catch (err) {
+      if (!(err instanceof InsufficientGoldError)) throw err;
+      return res.status(400).json({ error: `Not enough ${coinName(from)} — the balance is ${req.character[COIN_COLUMN[from]]}.` });
+    }
+
+    emitCharacterUpdated(req);
+    const character = await loadFullCharacter(req.character.id);
+    res.status(201).json({ character: serializeCharacter(character, req.isOwner, req.isDM), received });
   } catch (err) {
     next(err);
   }
@@ -1040,7 +1177,7 @@ for (const gear of GEAR) {
 // ---------------------------------------------------------------------------
 
 const giveSchema = z.discriminatedUnion('kind', [
-  z.object({ kind: z.literal('gold'), toCharacterId: z.string(), amount: z.number().int().min(1) }),
+  z.object({ kind: z.literal('gold'), toCharacterId: z.string(), amount: z.number().int().min(1), currency: z.enum(CURRENCIES).default('GOLD') }),
   z.object({ kind: z.literal('weapon'), toCharacterId: z.string(), id: z.string(), quantity: z.number().int().min(1).default(1) }),
   z.object({ kind: z.literal('item'), toCharacterId: z.string(), id: z.string(), quantity: z.number().int().min(1).default(1) }),
   z.object({ kind: z.literal('spell'), toCharacterId: z.string(), id: z.string() }),
@@ -1067,8 +1204,10 @@ router.post('/:id/give', requireCharacterAccess({ write: true }), async (req, re
     try {
       await prisma.$transaction(async (tx) => {
         if (give.kind === 'gold') {
-          await adjustGold(tx, { characterId: giver.id, amount: -give.amount, reason: `Gave to ${recipient.name}`, userId: req.user.id });
-          await adjustGold(tx, { characterId: recipient.id, amount: give.amount, reason: `Received from ${giver.name}`, userId: req.user.id });
+          // The giver pays from their whole purse, with change; the recipient gets the coins named.
+          const coins = { amount: give.amount, currency: give.currency, userId: req.user.id };
+          await spendCoins(tx, { ...coins, characterId: giver.id, reason: `Gave to ${recipient.name}` });
+          await adjustGold(tx, { ...coins, characterId: recipient.id, reason: `Received from ${giver.name}` });
           return;
         }
 
@@ -1102,7 +1241,7 @@ router.post('/:id/give', requireCharacterAccess({ write: true }), async (req, re
       });
     } catch (err) {
       if (err instanceof InsufficientGoldError) {
-        return res.status(400).json({ error: `Not enough gold — ${giver.name} has ${giver.gold}.` });
+        return res.status(400).json({ error: notEnoughMoney(giver, give.amount, give.currency || 'GOLD') });
       }
       if (err instanceof GiveError) return res.status(400).json({ error: err.message });
       throw err;

backend/src/routes/encounters.routes.js

@@ -4,9 +4,9 @@ const prisma = require('../db');
 const { requireAuth } = require('../middleware/auth');
 const { loadCampaignMembership } = require('../middleware/campaignAccess');
 const { computeCharacterSheet, computeWeaponStats, canUseGear, abilityModifier, MAX_GEAR_LEVEL } = require('../game/calculations');
-const { adjustGold, giveGear } = require('../utils/grants');
+const { CURRENCIES, InsufficientGoldError, adjustGold, spendCoins, giveGear } = require('../utils/grants');
 const { moveCharacters, visitedLocationIds } = require('../utils/locations');
-const { absorbDamage } = require('../utils/hp');
+const { NO_DEATH_SAVES, lifeState, deathSaveInfo, changeHp } = require('../utils/hp');
 
 const router = express.Router();
 
@@ -66,6 +66,43 @@ function initiativeBonus({ character, monster }) {
   return 0;
 }
 
+// Out of the fight: a dead character, or a monster or NPC brought to 0 HP.
+// The fallen are hidden from the players and skipped in the turn order; the
+// DM still sees them. It is worked out from HP each time, never stored, so
+// healing a monster or reviving a character brings them straight back. Takes
+// a participant with its character loaded.
+function isFallen(p) {
+  if (p.character) return lifeState(p.character) === 'DEAD';
+  return p.maxHp > 0 && p.currentHp <= 0;
+}
+
+// The first combatant still standing at or after `from` in the order, going
+// round to the top when the end is reached. If nobody is standing, whoever is
+// at `from`.
+function standingFrom(order, from) {
+  for (let step = 0; step < order.length; step += 1) {
+    const p = order[(from + step) % order.length];
+    if (!isFallen(p)) return p;
+  }
+  return order[from % order.length] ?? null;
+}
+
+// An encounter's combatants in turn order, with what isFallen needs.
+async function loadTurnOrder(encounterId) {
+  const participants = await prisma.encounterParticipant.findMany({
+    where: { encounterId },
+    include: { character: { select: { currentHp: true, deathSaveFailures: true, stable: true } } },
+  });
+  return inTurnOrder(participants);
+}
+
+// The spell a character would raise the dead with: one flagged as reviving
+// in the campaign's spell list, at a level they can cast. Takes a character
+// with its spells loaded.
+function revivalSpell(character) {
+  return character.spells.map((cs) => cs.spell).find((spell) => spell.revives && canUseGear(character.level, spell.level));
+}
+
 const initiativeRollSchema = z.number().int().min(1, 'An initiative roll is a d20: 1 to 20').max(20, 'An initiative roll is a d20: 1 to 20');
 
 // What every campaign member sees about a character in an encounter: the
@@ -103,6 +140,8 @@ function characterCombatInfo(character) {
     armorClass: sheet.armorClass,
     maxHp: sheet.hp.max,
     tempHp: character.tempHp,
+    deathSaves: deathSaveInfo(character),
+    canRevive: Boolean(revivalSpell(character)),
     speed: sheet.speed,
     initiativeBonus: sheet.initiative,
     passivePerception: sheet.passivePerception,
@@ -116,9 +155,16 @@ function characterCombatInfo(character) {
   };
 }
 
+// What is for sale, oldest first, with the weapon or item itself.
+const WARES = { include: { weapon: true, item: true }, orderBy: { createdAt: 'asc' } };
+
 // The DM gets everything. Players get the scene as their characters see it:
 // no DM notes, no monster stat blocks, no NPC secrets or stats, and only the
-// rewards that have actually been handed out.
+// rewards that have actually been handed out. What an NPC sells and the rate
+// they change money at are for everyone: `npc.wares`, `npc.exchangeGold` and
+// `npc.exchangeCash`, and the scene's own `wares`. The fallen (isFallen) are left
+// out of a player's list altogether; of those, only the dead characters are
+// named, in `fallen`, so an ally can try to revive them.
 //
 // `viewerId` is the user the payload is for. A player is told where a scene
 // is once one of their characters has been there, and — when the campaign
@@ -141,21 +187,27 @@ async function serializeEncounter(encounterId, isDM, viewerId) {
             },
           },
           monster: true,
-          npc: true,
+          npc: { include: { wares: WARES } },
         },
       },
       rewards: { include: { weapon: true, item: true }, orderBy: { createdAt: 'asc' } },
+      wares: WARES,
     },
   });
   if (!encounter) return encounter;
 
   const hideHp = !isDM && !encounter.campaign.showMonsterHp;
-  const participants = inTurnOrder(encounter.participants).map((p) => {
+  const inOrder = inTurnOrder(encounter.participants);
+  const hiddenIds = new Set(inOrder.filter(isFallen).map((p) => p.id));
+  const fallen = inOrder
+    .filter((p) => p.character && hiddenIds.has(p.id))
+    .map((p) => ({ participantId: p.id, characterId: p.character.id, name: p.displayName }));
+  const participants = inOrder.filter((p) => isDM || !hiddenIds.has(p.id)).map((p) => {
     const { character, monster, npc, ...row } = p;
     // The bonus is part of a monster's stat block, so only the DM gets it for
     // those; a character's is on their sheet for all to see.
     const bonus = isDM || character ? { initiativeBonus: initiativeBonus(p) } : {};
-    const out = { ...row, ...bonus, kind: npc || p.npcId ? 'NPC' : p.isMonster ? 'MONSTER' : 'CHARACTER' };
+    const out = { ...row, ...bonus, kind: npc || p.npcId ? 'NPC' : p.isMonster ? 'MONSTER' : 'CHARACTER', hidden: hiddenIds.has(p.id) };
     if (character) {
       // A character combatant's HP is the character's own HP, not a
       // per-encounter copy, so the tracker and the sheet can never disagree.
@@ -186,7 +238,10 @@ async function serializeEncounter(encounterId, isDM, viewerId) {
     locationId: knowsPlace ? scene.locationId : null,
     location: knowsPlace ? location : null,
     ...(isDM ? { dmNotes } : {}),
+    // A player is not told that someone they cannot see is being targeted.
+    targetParticipantIds: isDM ? scene.targetParticipantIds : scene.targetParticipantIds.filter((id) => !hiddenIds.has(id)),
     participants,
+    fallen,
     rewards: isDM ? rewards : rewards.filter((r) => r.awardedAt),
   };
 }
@@ -254,13 +309,15 @@ router.patch('/:id', requireEncounterAccess, requireDM, async (req, res, next) =
       if (!location) return res.status(400).json({ error: 'That location is not part of this campaign.' });
     }
 
-    // Starting a battle puts the first combatant in the initiative order on turn.
+    // Starting a battle puts the first combatant still standing on turn.
     const mode = data.mode ?? req.encounter.mode;
     if (data.status === 'ACTIVE' && mode === 'BATTLE' && !req.encounter.activeParticipantId) {
-      const participants = await prisma.encounterParticipant.findMany({ where: { encounterId: req.encounter.id } });
-      data.activeParticipantId = inTurnOrder(participants)[0]?.id ?? null;
+      data.activeParticipantId = standingFrom(await loadTurnOrder(req.encounter.id), 0)?.id ?? null;
     }
 
+    // Targets belong to the moment; beginning, ending or reopening clears them.
+    if (data.status && data.status !== req.encounter.status) data.targetParticipantIds = [];
+
     await prisma.encounter.update({ where: { id: req.encounter.id }, data });
     await respondWithEncounter(req, res);
   } catch (err) {
@@ -313,6 +370,10 @@ router.post('/:id/participants', requireEncounterAccess, requireDM, async (req,
       if (!character || character.campaignId !== req.encounter.campaignId) {
         return res.status(400).json({ error: 'That character is not part of this campaign.' });
       }
+      // The dead stay where they fell: they join no new scene until revived.
+      if (lifeState(character) === 'DEAD') {
+        return res.status(400).json({ error: `${character.name} is dead and cannot join an encounter. Revive them first.` });
+      }
       currentHp = character.currentHp;
       maxHp = computeCharacterSheet(character, character.skillProficiencies, character.saveProficiencies).hp.max;
       resolvedName = displayName || character.name;
@@ -399,10 +460,14 @@ router.patch('/:id/participants/:participantId', requireEncounterAccess, async (
       const maxHp = computeCharacterSheet(character, character.skillProficiencies, character.saveProficiencies).hp.max;
       data.maxHp = maxHp;
       if (data.currentHp !== undefined) {
-        // Temp HP soaks damage first; what is left lands on the character.
-        const after = absorbDamage(character.currentHp, character.tempHp, data.currentHp);
-        data.currentHp = clamp(after.currentHp, 0, maxHp);
-        await prisma.character.update({ where: { id: character.id }, data: { currentHp: data.currentHp, tempHp: after.tempHp } });
+        if (lifeState(character) === 'DEAD' && data.currentHp > 0) {
+          return res.status(400).json({ error: `${character.name} is dead. Revive them before healing.` });
+        }
+        // Temp HP soaks damage first; what is left lands on the character,
+        // and at 0 HP it moves their death saves too.
+        const after = changeHp(character, data.currentHp, maxHp);
+        data.currentHp = after.currentHp;
+        await prisma.character.update({ where: { id: character.id }, data: after });
         emitCharacterUpdated(req, character.id);
       }
     } else if (data.currentHp !== undefined) {
@@ -420,15 +485,20 @@ router.patch('/:id/participants/:participantId', requireEncounterAccess, async (
 
 router.delete('/:id/participants/:participantId', requireEncounterAccess, requireDM, async (req, res, next) => {
   try {
-    const participants = await prisma.encounterParticipant.findMany({ where: { encounterId: req.encounter.id } });
-    const order = inTurnOrder(participants);
+    const order = await loadTurnOrder(req.encounter.id);
     const index = order.findIndex((p) => p.id === req.params.participantId);
     if (index === -1) return res.status(404).json({ error: 'Combatant not found in this encounter' });
 
-    // Removing whoever is on turn passes the turn to the next combatant.
-    if (req.encounter.activeParticipantId === req.params.participantId) {
-      const next = order.length > 1 ? order[(index + 1) % order.length] : null;
-      await prisma.encounter.update({ where: { id: req.encounter.id }, data: { activeParticipantId: next ? next.id : null } });
+    // Removing whoever is on turn passes the turn to the next combatant still
+    // standing, and their targets go with the turn. Removing a target just
+    // unmarks it.
+    const { activeParticipantId, targetParticipantIds } = req.encounter;
+    if (activeParticipantId === req.params.participantId) {
+      const next = standingFrom([...order.slice(index + 1), ...order.slice(0, index)], 0);
+      await prisma.encounter.update({ where: { id: req.encounter.id }, data: { activeParticipantId: next ? next.id : null, targetParticipantIds: [] } });
+    } else if (targetParticipantIds.includes(req.params.participantId)) {
+      const left = targetParticipantIds.filter((id) => id !== req.params.participantId);
+      await prisma.encounter.update({ where: { id: req.encounter.id }, data: { targetParticipantIds: left } });
     }
     await prisma.encounterParticipant.delete({ where: { id: req.params.participantId } });
     await respondWithEncounter(req, res);
@@ -437,25 +507,118 @@ router.delete('/:id/participants/:participantId', requireEncounterAccess, requir
   }
 });
 
+// A dead character can be brought back in the middle of a battle by an ally:
+// the character on turn, if they are on their feet and can cast a spell that
+// raises the dead (revivalSpell). The dead come back at 1 HP, and with that
+// are back in everyone's list. A player tries it for their own character; the
+// DM for whoever is on turn. (The DM can also revive anyone outright, through
+// the character's death saves.)
+router.post('/:id/participants/:participantId/revive', requireEncounterAccess, async (req, res, next) => {
+  try {
+    const { mode, status, activeParticipantId } = req.encounter;
+    const onTurnId = mode === 'BATTLE' && status === 'ACTIVE' ? activeParticipantId : null;
+    const onTurn = onTurnId
+      ? await prisma.encounterParticipant.findFirst({
+          where: { id: onTurnId, encounterId: req.encounter.id },
+          include: { character: { include: { spells: { include: { spell: true } } } } },
+        })
+      : null;
+    const reviver = onTurn?.character;
+    if (!req.isDM && (!reviver || reviver.userId !== req.user.id)) {
+      return res.status(403).json({ error: "You can only try to revive someone on your own character's turn" });
+    }
+    if (!reviver) return res.status(400).json({ error: 'Only a character on turn in a battle can try to revive someone.' });
+
+    const target = await prisma.encounterParticipant.findUnique({ where: { id: req.params.participantId }, include: { character: true } });
+    if (!target || target.encounterId !== req.encounter.id) {
+      return res.status(404).json({ error: 'Combatant not found in this encounter' });
+    }
+    if (!target.character || lifeState(target.character) !== 'DEAD') {
+      return res.status(400).json({ error: `${target.displayName} is not dead.` });
+    }
+    if (lifeState(reviver) !== 'UP') return res.status(400).json({ error: `${reviver.name} is in no state to revive anyone.` });
+
+    const spell = revivalSpell(reviver);
+    if (!spell) return res.status(400).json({ error: `${reviver.name} has no spell that can bring back the dead.` });
+
+    await prisma.character.update({ where: { id: target.character.id }, data: { currentHp: 1, ...NO_DEATH_SAVES } });
+    await prisma.encounterParticipant.update({ where: { id: target.id }, data: { currentHp: 1 } });
+    emitCharacterUpdated(req, target.character.id);
+    await respondWithEncounter(req, res, 200, { revivedWith: spell.name });
+  } catch (err) {
+    next(err);
+  }
+});
+
+// ---------------------------------------------------------------------------
+// Targets — who the combatant on turn is going for
+// ---------------------------------------------------------------------------
+
+// The whole list, in the order picked; an empty one clears it.
+const targetsSchema = z.object({ participantIds: z.array(z.string()).max(50) });
+
+// Combatants can be marked as targets, for everyone to see; the DM's screen
+// then offers to apply damage to them. One is an ordinary attack, more is an
+// area attack. The DM can mark anyone at any time. A player can while their
+// own character is on turn in a battle. Nobody can mark the combatant who is
+// on turn: you don't target yourself.
+router.put('/:id/targets', requireEncounterAccess, async (req, res, next) => {
+  try {
+    const parsed = targetsSchema.safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const participantIds = [...new Set(parsed.data.participantIds)];
+
+    // Whoever is on turn, when a battle is under way.
+    const { mode, status, activeParticipantId } = req.encounter;
+    const onTurnId = mode === 'BATTLE' && status === 'ACTIVE' ? activeParticipantId : null;
+
+    if (!req.isDM) {
+      const ownTurn = onTurnId
+        ? await prisma.encounterParticipant.findFirst({
+            where: { id: onTurnId, encounterId: req.encounter.id, character: { userId: req.user.id } },
+            select: { id: true },
+          })
+        : null;
+      if (!ownTurn) return res.status(403).json({ error: "You can only pick targets on your own character's turn" });
+    }
+
+    if (onTurnId && participantIds.includes(onTurnId)) {
+      return res.status(400).json({ error: 'The combatant on turn cannot be their own target' });
+    }
+
+    // A player can only mark who they can see: to them the fallen are not there.
+    const order = await loadTurnOrder(req.encounter.id);
+    const markable = new Set(order.filter((p) => req.isDM || !isFallen(p)).map((p) => p.id));
+    if (!participantIds.every((id) => markable.has(id))) return res.status(400).json({ error: 'Combatant not found in this encounter' });
+
+    await prisma.encounter.update({ where: { id: req.encounter.id }, data: { targetParticipantIds: participantIds } });
+    await respondWithEncounter(req, res);
+  } catch (err) {
+    next(err);
+  }
+});
+
 // ---------------------------------------------------------------------------
 // Turns and rounds
 // ---------------------------------------------------------------------------
 
-// Passes the turn down the initiative order; going past the last combatant
-// starts the next round.
+// Passes the turn down the initiative order to the next combatant still
+// standing (the fallen have no turn); going past the last combatant starts
+// the next round.
 router.post('/:id/next-turn', requireEncounterAccess, requireDM, async (req, res, next) => {
   try {
-    const participants = await prisma.encounterParticipant.findMany({ where: { encounterId: req.encounter.id } });
-    const order = inTurnOrder(participants);
+    const order = await loadTurnOrder(req.encounter.id);
     if (order.length === 0) return res.status(400).json({ error: 'Add combatants before taking turns.' });
 
     const index = order.findIndex((p) => p.id === req.encounter.activeParticipantId);
-    const wrapped = index === order.length - 1;
+    const upNext = standingFrom(order, index + 1);
+    const wrapped = index !== -1 && order.indexOf(upNext) <= index;
     await prisma.encounter.update({
       where: { id: req.encounter.id },
       data: {
         status: 'ACTIVE',
-        activeParticipantId: order[wrapped || index === -1 ? 0 : index + 1].id,
+        activeParticipantId: upNext.id,
+        targetParticipantIds: [], // the next combatant picks their own
         ...(wrapped ? { currentRound: { increment: 1 } } : {}),
       },
     });
@@ -467,14 +630,15 @@ router.post('/:id/next-turn', requireEncounterAccess, requireDM, async (req, res
 
 router.post('/:id/advance-round', requireEncounterAccess, requireDM, async (req, res, next) => {
   try {
-    const participants = await prisma.encounterParticipant.findMany({ where: { encounterId: req.encounter.id } });
+    const order = await loadTurnOrder(req.encounter.id);
     const updated = await prisma.encounter.update({
       where: { id: req.encounter.id },
       data: {
         currentRound: { increment: 1 },
         status: 'ACTIVE',
+        targetParticipantIds: [],
         // A new round starts back at the top of the initiative order.
-        ...(req.encounter.mode === 'BATTLE' ? { activeParticipantId: inTurnOrder(participants)[0]?.id ?? null } : {}),
+        ...(req.encounter.mode === 'BATTLE' ? { activeParticipantId: standingFrom(order, 0)?.id ?? null } : {}),
       },
     });
     await syncCharacterLocations(req);
@@ -493,7 +657,7 @@ router.post('/:id/advance-round', requireEncounterAccess, requireDM, async (req,
 // ---------------------------------------------------------------------------
 
 const rewardSchema = z.discriminatedUnion('type', [
-  z.object({ type: z.literal('GOLD'), gold: z.number().int().min(1).max(1000000), note: z.string().trim().max(200).optional().nullable() }),
+  z.object({ type: z.literal('GOLD'), gold: z.number().int().min(1).max(1000000), currency: z.enum(CURRENCIES).default('GOLD'), note: z.string().trim().max(200).optional().nullable() }),
   z.object({
     type: z.literal('WEAPON'),
     weaponId: z.string(),
@@ -570,7 +734,7 @@ router.post('/:id/rewards/:rewardId/award', requireEncounterAccess, requireDM, a
 
     let recipients;
     if (parsed.data.split) {
-      if (reward.type !== 'GOLD') return res.status(400).json({ error: 'Only gold can be split.' });
+      if (reward.type !== 'GOLD') return res.status(400).json({ error: 'Only coins can be split.' });
       const participants = await prisma.encounterParticipant.findMany({
         where: { encounterId: req.encounter.id, characterId: { not: null } },
         include: { character: true },
@@ -599,7 +763,7 @@ router.post('/:id/rewards/:rewardId/award', requireEncounterAccess, requireDM, a
         const remainder = reward.gold % recipients.length;
         for (const [i, character] of recipients.entries()) {
           const amount = share + (i < remainder ? 1 : 0);
-          if (amount > 0) await adjustGold(tx, { characterId: character.id, amount, reason, userId: req.user.id });
+          if (amount > 0) await adjustGold(tx, { characterId: character.id, amount, currency: reward.currency, reason, userId: req.user.id });
         }
       } else {
         const kind = reward.type === 'WEAPON' ? 'weapon' : 'item';
@@ -619,4 +783,146 @@ router.post('/:id/rewards/:rewardId/award', requireEncounterAccess, requireDM, a
   }
 });
 
+// ---------------------------------------------------------------------------
+// Trade — changing gold and cash with an NPC, and buying what is for sale.
+// The DM sets the rates and the wares up (campaigns.routes.js); here the
+// players, or the DM for them, use them.
+// ---------------------------------------------------------------------------
+
+class TradeError extends Error {
+  constructor(message, status = 400) {
+    super(message);
+    this.status = status;
+  }
+}
+
+function money(amount, currency) {
+  return currency === 'CASH' ? `$${amount}` : `${amount} ${currency.toLowerCase()}`;
+}
+
+// Trading takes someone to trade with and the time to do it, so it happens
+// in a quest in progress and never in a battle.
+function assertTradeOpen(encounter) {
+  if (encounter.mode !== 'QUEST') throw new TradeError('Trading happens in a quest, not in a battle.');
+  if (encounter.status !== 'ACTIVE') throw new TradeError('Trading opens once the quest is in progress.');
+}
+
+// The character doing the trading: in this scene, alive, and the player's
+// own (the DM can trade for anyone).
+async function loadTrader(req, characterId) {
+  const row = await prisma.encounterParticipant.findFirst({ where: { encounterId: req.encounter.id, characterId }, include: { character: true } });
+  if (!row) throw new TradeError('That character is not in this encounter.');
+  if (!req.isDM && row.character.userId !== req.user.id) throw new TradeError('You can only trade for your own character.', 403);
+  if (isFallen(row)) throw new TradeError(`${row.character.name} is dead.`);
+  return row.character;
+}
+
+// An NPC to trade with has to be in the scene and still standing.
+async function loadTradingNpc(req, npcId) {
+  const row = await prisma.encounterParticipant.findFirst({ where: { encounterId: req.encounter.id, npcId }, include: { npc: true } });
+  if (!row || isFallen(row)) throw new TradeError('That NPC is not here to trade with.');
+  return row.npc;
+}
+
+function tradeRoute(handler) {
+  return async (req, res, next) => {
+    try {
+      assertTradeOpen(req.encounter);
+      await handler(req, res);
+    } catch (err) {
+      if (err instanceof TradeError) return res.status(err.status).json({ error: err.message });
+      next(err);
+    }
+  };
+}
+
+// Changes gold into cash, or cash into gold, at the NPC's own rate. Only
+// gold counts: silver and copper are not taken, and none come back. `amount`
+// is what is handed over, and has to come to a whole number the other way.
+router.post(
+  '/:id/exchange',
+  requireEncounterAccess,
+  tradeRoute(async (req, res) => {
+    const parsed = z
+      .object({ characterId: z.string(), npcId: z.string(), from: z.enum(['GOLD', 'CASH']), amount: z.number().int().min(1).max(1000000) })
+      .safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const { characterId, npcId, from, amount } = parsed.data;
+    const to = from === 'GOLD' ? 'CASH' : 'GOLD';
+
+    const character = await loadTrader(req, characterId);
+    const npc = await loadTradingNpc(req, npcId);
+    if (!npc.exchangeGold || !npc.exchangeCash) throw new TradeError(`${npc.name} does not change money.`);
+    const rate = { GOLD: npc.exchangeGold, CASH: npc.exchangeCash };
+    if (amount % rate[from] !== 0) {
+      throw new TradeError(
+        `${npc.name} gives ${money(rate.CASH, 'CASH')} for ${money(rate.GOLD, 'GOLD')}: hand over ${from.toLowerCase()} in multiples of ${rate[from]}.`
+      );
+    }
+    const received = (amount / rate[from]) * rate[to];
+
+    try {
+      await prisma.$transaction(async (tx) => {
+        const base = { characterId: character.id, userId: req.user.id };
+        await adjustGold(tx, { ...base, currency: from, amount: -amount, reason: `Changed with ${npc.name} for ${money(received, to)}` });
+        await adjustGold(tx, { ...base, currency: to, amount: received, reason: `Changed with ${npc.name} from ${money(amount, from)}` });
+      });
+    } catch (err) {
+      if (!(err instanceof InsufficientGoldError)) throw err;
+      throw new TradeError(`${character.name} only has ${money(from === 'GOLD' ? character.gold : character.cash, from)}.`);
+    }
+
+    emitCharacterUpdated(req, character.id);
+    await respondWithEncounter(req, res, 201, { received, currency: to });
+  })
+);
+
+// Buys something that is for sale here: from an NPC in the scene, or from the
+// scene itself. The price is paid from the purse (coins make change; a cash
+// price takes cash), and the weapon or item joins what the character holds.
+router.post(
+  '/:id/wares/:wareId/buy',
+  requireEncounterAccess,
+  tradeRoute(async (req, res) => {
+    const parsed = z.object({ characterId: z.string(), quantity: z.number().int().min(1).max(999).default(1) }).safeParse(req.body);
+    if (!parsed.success) return res.status(400).json({ error: parsed.error.flatten() });
+    const { characterId, quantity } = parsed.data;
+
+    const character = await loadTrader(req, characterId);
+    const ware = await prisma.saleOffer.findUnique({ where: { id: req.params.wareId }, include: { weapon: true, item: true } });
+    if (!ware || ware.campaignId !== req.encounter.campaignId || (ware.encounterId && ware.encounterId !== req.encounter.id)) {
+      throw new TradeError('That is not for sale here.', 404);
+    }
+    const seller = ware.npcId ? (await loadTradingNpc(req, ware.npcId)).name : null;
+    const kind = ware.weapon ? 'weapon' : 'item';
+    const entry = ware[kind];
+    const total = ware.price * quantity;
+
+    try {
+      await prisma.$transaction(async (tx) => {
+        if (ware.stock !== null) {
+          // The atomic decrement is the stock check: two buyers can't both take the last one.
+          const taken = await tx.saleOffer.updateMany({ where: { id: ware.id, stock: { gte: quantity } }, data: { stock: { decrement: quantity } } });
+          if (taken.count === 0) throw new TradeError(ware.stock === 0 ? `${entry.name} is sold out.` : `Only ${ware.stock} of ${entry.name} left.`);
+        }
+        const what = `${quantity > 1 ? `${quantity} × ` : ''}${entry.name}`;
+        await spendCoins(tx, {
+          characterId: character.id,
+          amount: total,
+          currency: ware.currency,
+          reason: seller ? `Bought ${what} from ${seller}` : `Bought ${what}`,
+          userId: req.user.id,
+        });
+        await giveGear(tx, kind, { characterId: character.id, entry, quantity, level: ware.level });
+      });
+    } catch (err) {
+      if (!(err instanceof InsufficientGoldError)) throw err;
+      throw new TradeError(`${character.name} can't afford that: it costs ${money(total, ware.currency)}.`);
+    }
+
+    emitCharacterUpdated(req, character.id);
+    await respondWithEncounter(req, res, 201);
+  })
+);
+
 module.exports = router;

backend/src/utils/grants.js

@@ -1,24 +1,120 @@
-// The two ways a character's belongings change: gold through the ledger, and
+// The two ways a character's belongings change: coins through the ledger, and
 // gear from the campaign pools. Shared by the character sheet routes and by
 // encounter rewards so both follow the same rules. Every function takes a
 // Prisma client or transaction client as `db`.
 
+// The coins, and what each is worth counted in copper: silver is 0.1 gold and
+// copper is 0.01 gold, so 1 gold = 10 silver = 100 copper and 1 silver = 10
+// copper. Whole numbers keep exchanges exact.
+const COINS = ['GOLD', 'SILVER', 'COPPER'];
+const COIN_VALUE = { GOLD: 100, SILVER: 10, COPPER: 1 };
+// Everything a purse can hold: the coins, plus cash ($) — modern money for
+// crossover worlds. Cash has no worth in coins, so it is never exchanged for
+// them and never used to make change.
+const CURRENCIES = [...COINS, 'CASH'];
+// Each currency is its own column on the character.
+const COIN_COLUMN = { GOLD: 'gold', SILVER: 'silver', COPPER: 'copper', CASH: 'cash' };
+
 class InsufficientGoldError extends Error {}
 
-// amount is signed: positive = gained, negative = spent. Writes the ledger row
-// and returns it; throws InsufficientGoldError if the balance would go below 0
-// (inside a transaction, that rolls the whole thing back).
-async function adjustGold(db, { characterId, amount, reason, userId, include }) {
+// amount is signed: positive = gained, negative = spent, in `currency` coins.
+// Writes the ledger row and returns it; throws InsufficientGoldError if that
+// coin's balance would go below 0 (inside a transaction, that rolls the whole
+// thing back). This moves exactly the coins named and nothing else; to pay a
+// price out of whatever coins the purse holds, use spendCoins.
+async function adjustGold(db, { characterId, amount, currency = 'GOLD', reason, userId, include }) {
+  const column = COIN_COLUMN[currency];
   // The atomic increment is the balance check: two spends racing each other
   // can't both pass a stale read.
-  const updated = await db.character.update({ where: { id: characterId }, data: { gold: { increment: amount } } });
-  if (updated.gold < 0) throw new InsufficientGoldError();
+  const updated = await db.character.update({ where: { id: characterId }, data: { [column]: { increment: amount } } });
+  if (updated[column] < 0) throw new InsufficientGoldError();
   return db.goldTransaction.create({
-    data: { characterId, amount, balanceAfter: updated.gold, reason: reason || null, createdById: userId },
+    data: { characterId, currency, amount, balanceAfter: updated[column], reason: reason || null, createdById: userId },
     include,
   });
 }
 
+// Works out which coins leave (and come back as change) when a purse pays
+// `amount` coins of `currency`. Returns the change to each balance, e.g.
+// { GOLD: -1, SILVER: 7, COPPER: 0 } for 3 silver paid from a purse with only
+// gold in it — or null if the whole purse isn't worth that much.
+//   1. Coins of the kind asked for go first.
+//   2. Any shortfall is met by breaking the nearest bigger coin; the change
+//      comes back in as few coins as possible.
+//   3. Only if there are no bigger coins left are smaller ones counted out.
+function planPayment(purse, currency, amount) {
+  const worth = (coin) => COIN_VALUE[coin];
+  const delta = { GOLD: 0, SILVER: 0, COPPER: 0 };
+  const left = (coin) => purse[coin] + delta[coin];
+  let owed = amount * worth(currency);
+  if (COINS.reduce((sum, coin) => sum + purse[coin] * worth(coin), 0) < owed) return null;
+
+  const pay = (coin, count) => {
+    delta[coin] -= count;
+    owed -= count * worth(coin);
+  };
+  pay(currency, Math.min(purse[currency], amount));
+
+  const bigger = COINS.filter((coin) => worth(coin) > worth(currency)).reverse(); // nearest first
+  for (const coin of bigger) {
+    if (owed <= 0) break;
+    pay(coin, Math.min(left(coin), Math.ceil(owed / worth(coin))));
+    // Overpaid: hand the difference back, biggest coins first.
+    let change = -owed;
+    for (const small of COINS.filter((c) => worth(c) < worth(coin))) {
+      if (change <= 0) break;
+      const count = Math.floor(change / worth(small));
+      delta[small] += count;
+      change -= count * worth(small);
+    }
+    if (owed < 0) owed = 0;
+  }
+
+  for (const coin of COINS.filter((c) => worth(c) < worth(currency))) {
+    if (owed <= 0) break;
+    pay(coin, Math.min(left(coin), Math.floor(owed / worth(coin))));
+  }
+  return delta;
+}
+
+// Pays `amount` coins of `currency` out of a character's purse, making change
+// as needed (see planPayment). Every coin that moved gets its own ledger row;
+// the rows are returned, the one in `currency` first when there is one. Throws
+// InsufficientGoldError if the purse as a whole can't cover it. Cash is paid in
+// cash alone: coins don't cover it, and it doesn't cover coins.
+async function spendCoins(db, { characterId, amount, currency = 'GOLD', reason, userId, include }) {
+  if (!COINS.includes(currency)) return [await adjustGold(db, { characterId, amount: -amount, currency, reason, userId, include })];
+  const character = await db.character.findUnique({ where: { id: characterId }, select: { gold: true, silver: true, copper: true } });
+  const purse = { GOLD: character.gold, SILVER: character.silver, COPPER: character.copper };
+  const delta = planPayment(purse, currency, amount);
+  if (!delta) throw new InsufficientGoldError();
+
+  const moved = COINS.filter((coin) => delta[coin] !== 0).sort((a, b) => (b === currency) - (a === currency));
+  const madeChange = moved.some((coin) => coin !== currency);
+  const label = reason || 'Spent';
+  const rows = [];
+  for (const coin of moved) {
+    rows.push(
+      await adjustGold(db, {
+        characterId,
+        amount: delta[coin],
+        currency: coin,
+        // Says what the payment was when the coins that moved aren't the ones asked for.
+        reason: madeChange ? `${label} (paid ${amount} ${currency.toLowerCase()}, with change)` : reason,
+        userId,
+        include,
+      })
+    );
+  }
+  return rows;
+}
+
+// A purse's coins as one figure in gold, for messages: 265 copper-worth -> 2.65.
+function worthInGold(character) {
+  const copper = COINS.reduce((sum, coin) => sum + character[COIN_COLUMN[coin]] * COIN_VALUE[coin], 0);
+  return copper / COIN_VALUE.GOLD;
+}
+
 const HELD = {
   weapon: { model: 'characterWeapon', key: 'weaponId' },
   item: { model: 'inventoryItem', key: 'itemId' },
@@ -37,4 +133,4 @@ async function giveGear(db, kind, { characterId, entry, quantity = 1, level, equ
   });
 }
 
-module.exports = { InsufficientGoldError, adjustGold, giveGear };
+module.exports = { CURRENCIES, COINS, COIN_VALUE, COIN_COLUMN, InsufficientGoldError, adjustGold, planPayment, spendCoins, worthInGold, giveGear };

backend/src/utils/hp.js

@@ -9,4 +9,70 @@ function absorbDamage(currentHp, tempHp, requestedHp) {
   return { currentHp: requestedHp + absorbed, tempHp: tempHp - absorbed };
 }
 
-module.exports = { absorbDamage };
+// ---------------------------------------------------------------------------
+// At 0 HP — death saves
+// ---------------------------------------------------------------------------
+//
+// A character at 0 HP is dying: they roll a d20 each turn, and three successes
+// or three failures settle it. The tallies and the "stable" flag live on the
+// Character row, next to the HP they belong to.
+
+// Three successes steady a character; three failures kill them.
+const DEATH_SAVE_LIMIT = 3;
+
+const NO_DEATH_SAVES = { deathSaveSuccesses: 0, deathSaveFailures: 0, stable: false };
+
+// UP: on their feet. DYING: at 0 HP and rolling death saves. STABLE: at 0 HP
+// but no longer rolling. DEAD: three failures, or one blow too big to survive.
+function lifeState(character) {
+  if (character.deathSaveFailures >= DEATH_SAVE_LIMIT) return 'DEAD';
+  if (character.currentHp > 0) return 'UP';
+  return character.stable ? 'STABLE' : 'DYING';
+}
+
+// What the API sends about it, the same shape wherever a character's HP goes.
+function deathSaveInfo(character) {
+  return { state: lifeState(character), successes: character.deathSaveSuccesses, failures: character.deathSaveFailures };
+}
+
+// Turns a pair of tallies into what gets stored: the third failure is death,
+// and the third success makes the character stable, which clears the tallies.
+function settleDeathSaves(successes, failures) {
+  if (failures >= DEATH_SAVE_LIMIT) return { deathSaveSuccesses: successes, deathSaveFailures: DEATH_SAVE_LIMIT, stable: false };
+  if (successes >= DEATH_SAVE_LIMIT) return { ...NO_DEATH_SAVES, stable: true };
+  return { deathSaveSuccesses: successes, deathSaveFailures: failures, stable: false };
+}
+
+// Damage or healing on a finished character. `requestedHp` is the HP that was
+// asked for, which may be below zero or above max. Returns every column that
+// should be written: HP and temp HP, plus the death-save columns when the
+// change touches them.
+//
+// - Damage comes off temp HP first.
+// - Dropping to 0 starts the death saves from a clean slate.
+// - Damage taken while already at 0 is one failed save, and ends "stable".
+// - Damage that would leave as much as max HP still to take once HP is at 0
+//   kills outright.
+// - Any healing from 0 puts the character back up and clears the tallies.
+function changeHp(character, requestedHp, maxHp) {
+  const soaked = absorbDamage(character.currentHp, character.tempHp, requestedHp);
+  const after = { currentHp: Math.min(Math.max(soaked.currentHp, 0), maxHp), tempHp: soaked.tempHp };
+  if (after.currentHp > 0) return { ...after, ...NO_DEATH_SAVES };
+
+  const damage = character.currentHp - soaked.currentHp; // what got past temp HP
+  if (damage <= 0) return after;
+  if (-soaked.currentHp >= maxHp) return { ...after, ...settleDeathSaves(0, DEATH_SAVE_LIMIT) };
+  if (character.currentHp > 0) return { ...after, ...NO_DEATH_SAVES };
+  return { ...after, ...settleDeathSaves(character.deathSaveSuccesses, character.deathSaveFailures + 1) };
+}
+
+// A dying character's death save, from what the d20 showed: 10 or more is a
+// success, less is a failure, a 1 is two failures, and a 20 puts them back on
+// their feet with 1 HP.
+function rollDeathSave(character, roll) {
+  if (roll === 20) return { currentHp: 1, ...NO_DEATH_SAVES };
+  if (roll >= 10) return settleDeathSaves(character.deathSaveSuccesses + 1, character.deathSaveFailures);
+  return settleDeathSaves(character.deathSaveSuccesses, character.deathSaveFailures + (roll === 1 ? 2 : 1));
+}
+
+module.exports = { absorbDamage, DEATH_SAVE_LIMIT, NO_DEATH_SAVES, lifeState, deathSaveInfo, settleDeathSaves, changeHp, rollDeathSave };

backend/src/utils/hp.test.js

@@ -0,0 +1,84 @@
+const { lifeState, settleDeathSaves, changeHp, rollDeathSave } = require('./hp');
+
+const CLEAR = { deathSaveSuccesses: 0, deathSaveFailures: 0, stable: false };
+const hero = (over = {}) => ({ currentHp: 10, tempHp: 0, ...CLEAR, ...over });
+
+describe('lifeState', () => {
+  test('reads up, dying, stable and dead off the row', () => {
+    expect(lifeState(hero())).toBe('UP');
+    expect(lifeState(hero({ currentHp: 0 }))).toBe('DYING');
+    expect(lifeState(hero({ currentHp: 0, stable: true }))).toBe('STABLE');
+    expect(lifeState(hero({ currentHp: 0, deathSaveFailures: 3 }))).toBe('DEAD');
+  });
+});
+
+describe('changeHp', () => {
+  test('ordinary damage and healing leave the death saves clear', () => {
+    expect(changeHp(hero(), 4, 20)).toEqual({ currentHp: 4, tempHp: 0, ...CLEAR });
+    expect(changeHp(hero(), 99, 20)).toEqual({ currentHp: 20, tempHp: 0, ...CLEAR });
+  });
+
+  test('dropping to 0 starts the saves from nothing', () => {
+    expect(changeHp(hero(), -5, 20)).toEqual({ currentHp: 0, tempHp: 0, ...CLEAR });
+  });
+
+  test('damage at 0 HP is a failed save and ends stable', () => {
+    const down = hero({ currentHp: 0, deathSaveSuccesses: 2, deathSaveFailures: 1 });
+    expect(changeHp(down, -3, 20)).toMatchObject({ currentHp: 0, deathSaveSuccesses: 2, deathSaveFailures: 2, stable: false });
+    expect(changeHp(hero({ currentHp: 0, stable: true }), -3, 20)).toMatchObject({ deathSaveFailures: 1, stable: false });
+    expect(lifeState(changeHp(hero({ currentHp: 0, deathSaveFailures: 2 }), -1, 20))).toBe('DEAD');
+  });
+
+  test('temp HP that soaks the whole blow costs no save', () => {
+    const down = hero({ currentHp: 0, tempHp: 5, deathSaveFailures: 1 });
+    expect(changeHp(down, -5, 20)).toEqual({ currentHp: 0, tempHp: 0 });
+  });
+
+  test('asking for the HP they already have at 0 changes nothing', () => {
+    expect(changeHp(hero({ currentHp: 0, deathSaveFailures: 2 }), 0, 20)).toEqual({ currentHp: 0, tempHp: 0 });
+  });
+
+  test('damage of max HP or more past zero kills outright', () => {
+    expect(lifeState(changeHp(hero(), -19, 20))).toBe('DYING');
+    expect(lifeState(changeHp(hero(), -20, 20))).toBe('DEAD');
+    expect(lifeState(changeHp(hero({ currentHp: 0 }), -20, 20))).toBe('DEAD');
+    // Temp HP counts against the blow first.
+    expect(lifeState(changeHp(hero({ tempHp: 1 }), -20, 20))).toBe('DYING');
+  });
+
+  test('healing from 0 puts them back up with a clean slate', () => {
+    const down = hero({ currentHp: 0, deathSaveSuccesses: 1, deathSaveFailures: 2 });
+    expect(changeHp(down, 1, 20)).toEqual({ currentHp: 1, tempHp: 0, ...CLEAR });
+    expect(changeHp(hero({ currentHp: 0, stable: true }), 6, 20)).toEqual({ currentHp: 6, tempHp: 0, ...CLEAR });
+  });
+});
+
+describe('rollDeathSave', () => {
+  const down = (successes, failures) => hero({ currentHp: 0, deathSaveSuccesses: successes, deathSaveFailures: failures });
+
+  test('10 or more succeeds, less fails, a 1 fails twice', () => {
+    expect(rollDeathSave(down(0, 0), 10)).toEqual({ deathSaveSuccesses: 1, deathSaveFailures: 0, stable: false });
+    expect(rollDeathSave(down(0, 0), 19)).toEqual({ deathSaveSuccesses: 1, deathSaveFailures: 0, stable: false });
+    expect(rollDeathSave(down(0, 0), 9)).toEqual({ deathSaveSuccesses: 0, deathSaveFailures: 1, stable: false });
+    expect(rollDeathSave(down(0, 0), 1)).toEqual({ deathSaveSuccesses: 0, deathSaveFailures: 2, stable: false });
+  });
+
+  test('the third success makes them stable and clears the tallies', () => {
+    expect(rollDeathSave(down(2, 2), 14)).toEqual({ ...CLEAR, stable: true });
+  });
+
+  test('the third failure is death, and never counts past three', () => {
+    expect(rollDeathSave(down(2, 2), 5)).toMatchObject({ deathSaveFailures: 3 });
+    expect(rollDeathSave(down(0, 2), 1)).toMatchObject({ deathSaveFailures: 3 });
+  });
+
+  test('a 20 is 1 HP and a clean slate', () => {
+    expect(rollDeathSave(down(0, 2), 20)).toEqual({ currentHp: 1, ...CLEAR });
+  });
+});
+
+describe('settleDeathSaves', () => {
+  test('failures win a tie at three', () => {
+    expect(settleDeathSaves(3, 3)).toMatchObject({ deathSaveFailures: 3, stable: false });
+  });
+});

docs/CHARACTERS.md

@@ -325,6 +325,50 @@ Example: a Fighter (d10) with CON 14 (+2) has 12 at level 1 and 28 at level 3.
 **Temp HP** is a tracked number shown beside HP. Damage is not taken from it
 automatically.
 
+### At 0 HP: death saves
+
+A character at 0 HP is in one of three states, shown on the sheet under the
+HP bar, on their encounter card, in the quick stats and in the party lists.
+
+| State | Meaning | How it ends |
+|---|---|---|
+| Dying | Rolling death saves | Three successes, three failures, healing, or being stabilised |
+| Stable | At 0 HP, no longer rolling | Healing wakes them; damage makes them Dying again |
+| Dead | Three failures, or one blow too big to survive | The DM's **Revive at 1 HP**, or an ally's reviving spell in a battle |
+
+**Rolling.** While Dying, type what the d20 showed and click **Death save**.
+The app does not roll it.
+
+| Roll | Result |
+|---|---|
+| 1 | Two failures |
+| 2 to 9 | One failure |
+| 10 to 19 | One success |
+| 20 | Back up with 1 HP, tallies cleared |
+
+- **Three successes:** Stable. The tallies are cleared.
+- **Three failures:** Dead.
+- **Stabilise** makes a Dying character Stable without a roll, for when
+  someone steadies them (a Medicine check, a healer's kit, a spell).
+- **Damage at 0 HP** is one failed save, and makes a Stable character Dying
+  again. Damage soaked entirely by temp HP does not count. The app cannot tell
+  a critical hit; the DM adds its second failure by clicking a pip.
+- **Massive damage:** if a blow leaves as much as the character's max HP
+  still to take once HP reaches 0, they are Dead at once. A character with
+  12 max HP on 5 HP dies from 17 damage or more.
+- **Healing** from 0, by any amount, puts the character back up and clears
+  the tallies and Stable.
+- **Dead** characters cannot be healed: Heal is refused with a message. The
+  DM clicks **Revive at 1 HP**, then heals as normal. In a battle, an ally
+  with a reviving spell can do the same on their own turn, and until then the
+  dead are hidden from the players' encounter screen: see
+  [ENCOUNTERS.md](ENCOUNTERS.md), section 6.
+- The **DM** can click a pip to set either tally by hand, to fix a mistake.
+
+Dropping to 0 always starts from empty tallies. None of this changes any
+other number on the sheet, and nothing is added to the conditions in an
+encounter.
+
 ## 8. Other derived stats
 
 | Stat | Formula |
@@ -509,17 +553,50 @@ character already has adds to the stack. Items have no effect on any stat. An
 item can carry optional dice (a potion's healing, a bomb's damage) that grow
 with its level exactly like a weapon's (section 10).
 
-**Money** is a single gold balance with a log behind it.
+**Money** is a purse of three coins, each counted on its own, with a log
+behind it.
 
-- The sheet's Money card shows the balance and every change to it: the amount,
-  what it was for, who recorded it, when, and the balance afterwards.
-- The **owning player and the DM** can both record a gain or a spend. Other
-  members can see the log but not add to it.
-- The balance **cannot go below zero**; a spend larger than the balance is
-  refused.
-- The log is the only way the balance changes. Entries cannot be edited or
+| Coin | Worth |
+|---|---|
+| Gold (gp) | 1 gold |
+| Silver (sp) | 0.1 gold — 10 to the gold |
+| Copper (cp) | 0.01 gold — 100 to the gold, 10 to the silver |
+
+- The sheet's Money card shows the three balances, what the purse is worth in
+  gold altogether, and every change: the amount and coin, what it was for, who
+  recorded it, when, and that coin's balance afterwards.
+- The **owning player and the DM** can both record a gain or a spend, choosing
+  the coin. Other players cannot see the purse or the log.
+- **Spending makes change for you.** A spend (or a gift to another character)
+  is paid from the whole purse. Coins of the kind named go first; if there
+  aren't enough, the nearest bigger coin is broken and the change comes back
+  in as few coins as possible; if there are no bigger coins, smaller ones are
+  counted out. Spending 3 silver from a purse of 5 gold leaves 4 gold and 7
+  silver. Each coin that moved gets its own log entry, marked "with change".
+- A spend is refused only when the **whole purse** isn't worth enough.
+- **Exchange** turns coins of one kind into another at the worth above, and
+  logs both sides. It moves exactly the coins named and has to come to whole
+  coins: silver into gold goes in tens, copper into silver in tens, copper
+  into gold in hundreds.
+- The log is the only way a balance changes. Entries cannot be edited or
   deleted; to correct a mistake, record the opposite entry.
-- There is one currency (gold). Silver, copper and so on are not tracked.
+- Starting gold (a campaign setting) is gold only. Encounter rewards and gifts
+  between characters can be in any coin, or in cash.
+- **Cash ($)** is a fourth balance for crossover worlds, counted in whole
+  dollars and shown as `$40`. It is gained, spent, given and awarded like a
+  coin and has its own log entries, but it has no worth in coins: it cannot
+  be exchanged on the sheet, a cash spend is paid from cash alone, and cash
+  is never broken to cover a coin spend. It shows in the purse only when
+  held.
+- **Gold and cash are changed for each other by an NPC**, not on the sheet.
+  An NPC the DM has given an exchange rate ("1 gold = $5") changes them
+  either way at that rate, in an NPC quest in progress that both the NPC and
+  the character are in. Only gold and cash: silver and copper are not taken.
+  Each NPC has their own rate. See [NPCS.md](NPCS.md), section 5.
+- **Buying.** In the same kind of scene a character can buy the weapons and
+  items an NPC, or the encounter itself, has for sale. The price is paid from
+  the purse like any other spend and logged as "Bought <thing> from <NPC>".
+  See [ENCOUNTERS.md](ENCOUNTERS.md), section 10.
 
 ### Giving to another character
 
@@ -569,7 +646,7 @@ character in the same campaign.
 | Party overview | One table of every character with an HP bar, AC, gold and location. |
 | Character sheet | Everything in this document. |
 | Character builder | A character that is still being built (section 2). |
-| Quick stats drawer | A combat summary: HP, AC, initiative, speed, proficiency bonus, spellcasting numbers, special abilities, and each weapon's attack and damage. |
+| Quick stats drawer (the ⚡ button: bottom right, or in the top bar on a phone) | A combat summary: HP, AC, initiative, speed, proficiency bonus, spellcasting numbers, special abilities, and each weapon's attack and damage. |
 | Encounter page | Characters taking part in a battle or quest (next section). |
 
 Changes are pushed live to everyone who has the campaign open, so sheets and
@@ -620,7 +697,9 @@ players never receive.
 - "Begin Battle" puts the highest initiative on turn. "Next Turn" passes the
   turn down the order, and going past the last combatant starts the next
   round. "Next Round" jumps straight to the top of the next round.
-- A combatant at 0 HP is marked Down but still takes its turn in the order.
+- A monster or NPC at 0 HP is marked Down; a character is Dying and makes
+  death saves on its card (section 7). Either still has its place in the
+  order.
 - Conditions (Prone, Poisoned, …) are picked from a list and removed with a
   click.
 
@@ -671,12 +750,15 @@ Another Campaign" card on its sheet.
 | View private notes | Yes | No | No |
 | Run the builder | Yes | Yes | No |
 | Change HP, temp HP, armor bonus | Yes | Yes | No |
+| Enter a death save, or stabilise | Yes | Yes | No |
+| Set death-save tallies by hand, revive from dead | No | Yes | No |
 | Edit special abilities, background, appearance (after the build) | No | Yes | No |
 | Tick Equipped / Prepared | Yes | Yes | No |
 | Give, remove or re-count weapons, spells and items | No | Yes | No |
 | Level a weapon or item up or down | No | Yes | No |
 | Record a gold gain or spend | Yes | Yes | No |
 | Give gold, weapons, items or spells to another character | Yes | Yes | No |
+| Change gold and cash with an NPC, or buy what is for sale, in a quest in progress | Yes | Yes | No |
 | View the money log, gold and inventory | Yes | Yes | No |
 | Change level, XP, location or speed override | No | Yes | No |
 | Post a character note | Yes | Yes | Yes |
@@ -707,13 +789,13 @@ calculations for them.
 - Armor and shields as items (only the single armor bonus number)
 - Weapon proficiency (everyone is proficient with everything)
 - Rolling attacks, damage, saves or checks for a character (the dice roller,
-  bottom left of every page, is a plain roller that knows nothing about the
-  sheet)
-- Death saves, conditions on the sheet, and resting
+  bottom left of every page, or the last button of the bottom bar on a phone,
+  is a plain roller that knows nothing about the sheet)
+- Conditions on the sheet, and resting
 - Automatic levelling from XP
 - Alignment, languages, tool proficiencies and backgrounds-as-rules
 - Encumbrance and item weight
-- Currencies other than gold, and item prices
+- Cents, and changing silver or copper for cash
 
 ## 20. Everything the builder offers
 

docs/ENCOUNTERS.md

@@ -19,9 +19,10 @@ This describes the code as it stands. The rules live in
 7. [Initiative, turns and rounds](#7-initiative-turns-and-rounds)
 8. [Conditions](#8-conditions)
 9. [Rewards](#9-rewards)
-10. [What each side sees](#10-what-each-side-sees)
-11. [Permissions](#11-permissions)
-12. [What is not modelled](#12-what-is-not-modelled)
+10. [Trade](#10-trade)
+11. [What each side sees](#11-what-each-side-sees)
+12. [Permissions](#12-permissions)
+13. [What is not modelled](#13-what-is-not-modelled)
 
 ---
 
@@ -46,11 +47,12 @@ time from the top of the page.
 | | Battle | NPC quest |
 |---|---|---|
 | For | A fight | A scene built around people and an objective |
-| Layout | Everyone in one list, in initiative order | Three groups: "People you meet", "The party", "Creatures" |
+| Layout | Everyone in one list, in initiative order; once in progress, those who have had their turn move to "Next Round" at the bottom | Three groups: "People you meet", "The party", "Creatures" |
 | Rounds and turns | Yes | No |
-| Initiative | The d20 roll, typed in per combatant; the bonus is added | Not shown |
+| Initiative | The d20 roll, typed in per combatant; the bonus is added | The same; each group lists highest first |
 | Start button | Begin Battle | Begin Quest |
 | End button | End Battle | Complete Quest |
+| Trade (section 10) | No | Yes, while in progress |
 
 Everything else (hit points, conditions, rewards, the scene description, DM
 notes) works the same in both.
@@ -86,6 +88,10 @@ goes to the top. The "Sort by" menu re-sorts the list by name, status, type or
 date instead; that choice is remembered per browser and changes nothing for
 anyone else. ▲ and ▼ only show while sorting by campaign order.
 
+The list shows **ten encounters a page**, with Prev and Next beneath it, and
+the DM's archived list is paged the same way. The order runs on across pages:
+moving the last encounter on a page down carries it to the top of the next.
+
 **Archive.** "Archive" (on the list or the encounter page) puts an encounter
 away without changing it. It moves to the DM's "Archived" section and
 disappears from the players' list; a player whose character is in it can still
@@ -111,7 +117,7 @@ The DM adds people from the "Add to the scene" panel.
 
 | Kind | Comes from | Can be added more than once |
 |---|---|---|
-| Character | The campaign's finished characters | No |
+| Character | The campaign's finished characters, except dead ones | No |
 | Monster | The campaign's monster list ([MONSTERS.md](MONSTERS.md)) | Yes |
 | NPC | The campaign's NPC list ([NPCS.md](NPCS.md)) | No |
 
@@ -131,6 +137,10 @@ Details start open for the DM and closed for players. Weapons and spells
 above a character's level are left out, because the character cannot use
 them.
 
+A **dead character cannot be added** to any encounter: they are left out of
+the list to pick from and the server refuses them, until they are revived. A
+character who dies stays in the encounters they were already in.
+
 The DM removes someone with "Remove" on their card. Removing whoever is on
 turn passes the turn to the next combatant.
 
@@ -149,18 +159,87 @@ The DM types an amount and clicks Damage or Heal on a card.
   monsters and NPCs it depends on the campaign setting "Players see the exact
   hit points of monsters and NPCs": on (the default) shows the numbers, off
   shows only the health bar. The DM always sees the numbers.
-- At 0 HP a combatant is marked **Down** and dimmed. It keeps its place in
-  the order; nothing is removed automatically.
+- At 0 HP a monster or NPC is **out of the fight**: see "The fallen" below.
+- A **character** at 0 HP is **Dying** instead, and its card grows a death-save
+  box: see below.
 - A character's temporary HP is shown beside its HP but is not used up
   automatically.
 
+### A character at 0 HP
+
+The full rules are in [CHARACTERS.md](CHARACTERS.md), section 7; the box on
+the card is the same one as on the sheet, and both change the same character.
+
+- **Dying.** The box shows two tallies, Saved and Failed, three pips each.
+  Type what the d20 showed and click **Death save**: 10 or more is a success,
+  less is a failure, a 1 is two failures, a 20 puts the character back up at
+  1 HP. The DM can do this for anyone; a player for their own character.
+- **Damage while down** is one failed save, added when the DM clicks Damage.
+  For a critical hit the DM clicks the next Failed pip to add the second.
+- **Stabilise** stops the saves without a roll (a Medicine check, a spell).
+  Three successes do the same. A stable character stays at 0 HP.
+- **Heal** on a dying or stable character puts them back up and clears the
+  tallies.
+- **Dead** after three failures, or when one blow leaves as much as the
+  character's max HP still to take after reaching 0. Healing is refused; the
+  DM clicks **Revive at 1 HP**, or an ally revives them (below).
+- The DM can click any pip to set a tally by hand.
+
+Nothing rolls by itself: the app does not prompt for a save when the turn
+comes round. A dying or stable character keeps its place in the order and
+still gets its turn.
+
+### The fallen
+
+A combatant is **out of the fight** when it is:
+
+- a **monster or NPC at 0 HP** (one with hit points to track), or
+- a **dead character**. Dying and stable characters are not: they stay in
+  view.
+
+What that does:
+
+- **Players no longer see it.** Its card is gone from their screen, along
+  with any target mark on it; the server does not send it to them at all.
+- **The DM's screen leaves it out as well**, until the DM ticks **Show dead**
+  above the list (the box shows how many there are, and only appears when
+  there are any). Ticked, they are listed in a group of their own at the
+  bottom, "Out of the fight, hidden from players", each with a "Hidden from
+  players" badge, and everything on the card still works. The tick is not
+  remembered: it is off again when the page is reopened.
+- **It has no turn.** Next Turn, Next Round and Begin Battle pass over it.
+- It stays in the encounter: nothing is removed, and gold is still split with
+  a dead character.
+
+It is worked out from hit points each time, not stored, so it undoes itself:
+heal a monster or NPC above 0, or revive a character, and they are back on
+everyone's screen and back in the turn order.
+
+**Reviving a dead character.** Players see dead characters by name only, in a
+**☠ Fallen** box above the list. There are two ways back:
+
+- The **DM** ticks Show dead and clicks **Revive at 1 HP** on the dead
+  character's card (or does it on the sheet), at any time.
+- An **ally** tries it: in a battle in progress, the player whose character is
+  **on turn** gets a **Try revive** button beside each name in the Fallen box,
+  if that character is capable. Capable means on their feet (above 0 HP) and
+  knowing a spell that is ticked **Revives** in the campaign's spell list
+  ([SPELLS.md](SPELLS.md)), at a level they can cast. The library's Revivify
+  (level 3) and Raise Dead (level 5) are ticked already.
+
+Either way the character comes back at 1 HP with the death saves cleared. The
+app does not use up the spell, check how long ago they died, or end the
+reviver's turn.
+
 ## 7. Initiative, turns and rounds
 
-Battles only.
+Initiative is entered in battles and quests alike. Turns and rounds are for
+battles only.
 
 - Each combatant has an **initiative roll** field. Type what the d20 showed,
   1 to 20; the field accepts nothing else. The app does not roll the die, but
-  it adds the bonus for you and shows the total: a character's initiative
+  it adds the bonus for you and shows the total, which can go past 20 (a 20 on
+  the die with a +3 bonus is 23): a character's initiative
   bonus from their sheet, a monster's Dexterity modifier, nothing for an NPC.
 - The DM can enter the roll for anyone, when adding them or on the card. A
   player can enter the roll for **their own character** on its card.
@@ -173,6 +252,71 @@ Battles only.
 - **Next Turn** passes the turn to the next in the order. After the last
   combatant it returns to the top and the **round** goes up by one.
 - **Next Round** skips straight to the top of the next round.
+- Anyone out of the fight (section 6, "The fallen") is passed over.
+- **The list follows the turn.** While a battle is in progress, whoever is on
+  turn is at the top of "Initiative order" with those still to act this round
+  beneath them. Each combatant whose turn has passed moves down to a **Next
+  Round** section at the bottom, still in initiative order. When the round
+  rolls over everyone is back in "Initiative order". Everyone sees the same
+  arrangement. Before the battle begins, and once it is complete, it is one
+  plain list.
+
+### Targets
+
+Combatants can be marked as **targets**: whoever is being attacked (or
+healed) right now. One target is an ordinary attack; more than one is an
+**area attack**.
+
+- Click **🎯 Target** beside a combatant's name to mark them; click it again
+  to unmark. Each one marked is added to the targets.
+- The **DM** can mark anyone at any time, in a battle or a quest. A **player**
+  can while their own character is on turn in a battle, so they can show the
+  DM who they are going for. A player cannot mark someone who is out of the
+  fight, and is not shown a mark the DM leaves on one.
+- The combatant **on turn** cannot be marked: nobody targets themselves, and
+  their card has no Target button until the turn passes. To heal or hurt them
+  on their own turn, use the buttons on their card.
+- A target's card is outlined in red for everyone and reads "Targeted by
+  <whoever is on turn>".
+- While anyone is marked the DM gets an **attack bar** above the list, which
+  stays in view while scrolling. It shows who is attacking whom, each target's
+  AC and HP, and the attacker's attacks: a character's equipped weapons (all
+  of them if none are equipped) and damaging spells, or a monster's or NPC's
+  attack and damage. The amount box is ready to type in; **Damage** (or
+  Enter) and **Heal** change HP exactly as the buttons on a card do.
+- Targets stay marked after damage, for a second attack. They are cleared
+  when the turn or round moves on, when the encounter begins, ends or is
+  reopened; a target that is removed from the encounter is unmarked.
+
+**Area attacks**
+
+An attack on several targets is harder to land and its damage is shared.
+
+- **Harder to hit.** Every target's AC counts as higher for each target
+  beyond the first, by the campaign's **area attack AC penalty**. The DM sets
+  it in the campaign settings, from 0 (no penalty) to 10; it starts at 2, which
+  gives:
+
+  | Targets | Added to each AC |
+  |---|---|
+  | 1 | 0 |
+  | 2 | +2 |
+  | 3 | +4 |
+  | 4 | +6 |
+
+  The attack bar shows the AC to beat with the penalty already added
+  ("17 (15 +2)"), and each target's card says "area attack, AC +2".
+- **Who was hit.** Each target has a tick box, ticked to begin with. Untick
+  anyone the roll missed; they take nothing.
+- **Sharing the amount.** Type the total. "Split between those hit" (the
+  default) shares it evenly, any remainder going one point each to the first
+  targets marked: 7 between three is 3, 2 and 2. "Full amount to each" gives
+  every target hit the whole amount. Each target's share is shown before it
+  is applied.
+- A target with no hit points to track is left out of the sharing.
+
+The app does not roll the attack or decide whether it hits: the DM compares
+the roll with the AC shown and types the damage.
 
 ## 8. Conditions
 
@@ -192,7 +336,7 @@ The DM lines up loot in the Rewards panel, on any encounter at any time.
 
 | Reward | What the DM sets |
 |---|---|
-| Gold | An amount |
+| Coins or cash | An amount, and which: gold, silver, copper or cash ($) |
 | Weapon | A weapon from the pool, a level (not below its starting level), a quantity |
 | Item | An item from the pool, a level, a quantity |
 
@@ -203,9 +347,9 @@ Each can carry a short note ("Goblin chief's purse").
 | Button | What happens |
 |---|---|
 | Award (pick a character) | The whole reward goes to that character. It can be any finished character in the campaign, not only those in the encounter. |
-| Split (gold only) | Shared evenly between the characters in the encounter. Any remainder goes one gold each, highest initiative first: 101 gold between two is 51 and 50. |
+| Split (coins and cash only) | Shared evenly between the characters in the encounter. Any remainder goes one each, highest initiative first: 101 gold between two is 51 and 50. |
 
-- **Gold** is added to the character's balance with a money-log entry reading
+- **Coins or cash** are added to the character's balance with a money-log entry reading
   "Reward: <encounter name>".
 - A **weapon or item** is added to what the character holds, at the reward's
   level, stacking with any they already have. If the character is below that
@@ -216,7 +360,48 @@ Each can carry a short note ("Goblin chief's purse").
 Until a reward is awarded only the DM can see it. Afterwards players see what
 it was and who received it.
 
-## 10. What each side sees
+## 10. Trade
+
+In an NPC quest the party can **change money** and **buy things**. Both take
+someone to deal with and the time to do it, so:
+
+- Trading is open only in an **NPC quest that is in progress**. Before "Begin
+  Quest" and after "Complete Quest" everything on offer is still shown, but
+  the buttons are off.
+- There is **no trading in a battle**. Switching a quest to a battle hides the
+  Trade card and the server refuses any trade; switching back brings it back.
+- An NPC trades only while they are **in the scene and not at 0 HP**.
+- The character trading has to be **in the encounter** and alive.
+
+The "Trade" card sits beside the scene, above Rewards. It appears for players
+when there is something to trade, and always for the DM in a quest.
+
+| Part of the card | What it does |
+|---|---|
+| Who is trading | Picks the character. A player chooses among their own characters in the scene; the DM among all of them. Their purse is shown beside it |
+| 💱 A money changer | One row per NPC in the scene who has an exchange rate. Type an amount, choose "gold into cash" or "cash into gold", and the button shows what comes back |
+| 🛒 "<NPC> sells" | Everything that NPC has for sale: what it is, its level and dice, the price, and how many are left. "Buy" buys one |
+| 🛒 "For sale here" | Things sold by the scene itself rather than by anyone in it |
+| Set up (DM only) | Puts weapons and items from the campaign pools up for sale at this encounter, and edits their price and stock |
+
+- **Changing money** uses the NPC's own rate, the same both ways, and only
+  gold and cash: no silver, no copper, no change. The amount handed over has
+  to be a whole multiple of that side of the rate. The full rules and
+  examples are in [NPCS.md](NPCS.md), section 5.
+- **Buying** pays the price from the character's purse (coins make change; a
+  cash price takes cash only), adds the weapon or item to what the character
+  holds at the level it is sold at, and uses up stock. A character below that
+  level holds it but cannot use it yet.
+- Every trade is written to the character's money log.
+- **An NPC's rate and wares are set on the campaign page**, under "Trade" on
+  the NPC's row, and follow the NPC into every quest they are in. **An
+  encounter's own wares are set here**, in the DM's part of the card, and
+  exist only in this encounter: a market stall, a vending machine, a chest
+  with a price tag.
+- Removing an NPC from the scene takes their rate and wares out of it.
+  Deleting the encounter deletes its own wares; what was bought stays bought.
+
+## 11. What each side sees
 
 | | DM | Players |
 |---|---|---|
@@ -225,13 +410,16 @@ it was and who received it.
 | Characters | Full card | Full card |
 | Monsters | Full stat block | Name, HP, conditions |
 | NPCs | Everything | Name, role, attitude, description, HP bar |
+| Monsters and NPCs at 0 HP | With "Show dead" ticked, marked hidden | Nothing |
+| Dead characters | Full card with "Show dead" ticked, marked hidden | The name only, in the Fallen box |
 | Rewards | All | Only awarded ones |
+| Exchange rates and things for sale | Yes | Yes, for NPCs they can see and for the scene itself |
 | Controls (add, damage, turns, rewards) | Yes | None |
 
 The server only sends a player what the right-hand column lists, so hidden
 information cannot be dug out of the page.
 
-## 11. Permissions
+## 12. Permissions
 
 | Action | DM | Players |
 |---|---|---|
@@ -243,20 +431,31 @@ information cannot be dug out of the page.
 | Add or remove anyone | Yes | No |
 | Change HP or conditions | Yes | No |
 | Enter an initiative roll | Yes, for anyone | For their own character only |
+| Mark targets | Yes, any time | On their own character's turn |
+| Enter a death save, or stabilise | Yes, for anyone | For their own character only |
+| Set death-save tallies by hand | Yes | No |
+| Revive a dead character outright | Yes | No |
+| Try to revive a dead character | Yes, for the character on turn | On their own character's turn, if it has a reviving spell |
 | Advance turns and rounds | Yes | No |
 | Add, remove or award rewards | Yes | No |
+| Set exchange rates, and put things up for sale | Yes | No |
+| Change money or buy, in a quest in progress | Yes, for any character in it | For their own character in it |
 
 People outside the campaign cannot open its encounters.
 
-## 12. What is not modelled
+## 13. What is not modelled
 
 - Rolling initiative, attacks, damage or saves (use the dice roller, bottom
-  left of every page)
+  left of every page, or in the bottom bar on a phone)
 - Applying an attack's damage automatically
-- Death saves and stabilising
+- Death saves for monsters and NPCs, and prompting for a save on a dying
+  character's turn
+- A roll, a spell slot or a time limit for reviving the dead
 - Conditions with durations or mechanical effects
 - Maps, positions, distances and areas of effect
 - Experience points and encounter difficulty
-- Spells as rewards
+- Spells as rewards, and spells for sale
+- Selling to an NPC, haggling, and buying more than one of a thing in a
+  single step
 - Renaming an encounter from the screen
 - A log of what happened during the encounter

docs/ITEMS.md

@@ -15,7 +15,7 @@ level up the same way weapons do), [SPELLS.md](SPELLS.md),
 4. [Item levels](#4-item-levels)
 5. [Dice on items](#5-dice-on-items)
 6. [Starting items](#6-starting-items)
-7. [Items as rewards](#7-items-as-rewards)
+7. [Items as rewards and for sale](#7-items-as-rewards-and-for-sale)
 8. [Permissions](#8-permissions)
 9. [What is not modelled](#9-what-is-not-modelled)
 
@@ -121,13 +121,20 @@ In the builder's equipment step a new character can pick items that are:
 Starting items and starting weapons share the campaign's "starting items"
 allowance. Each arrives at level 1, quantity 1, unequipped.
 
-## 7. Items as rewards
+## 7. Items as rewards and for sale
 
 On an encounter the DM can line up an item as a reward, at a chosen level and
 quantity, and later award it to a character. Awarding adds it to the
 character's inventory, stacking with any they already hold. See
 [ENCOUNTERS.md](ENCOUNTERS.md).
 
+The DM can also put an item **up for sale**, at a level, a price (in gold,
+silver, copper or cash) and an optional stock. An NPC can sell it, wherever
+that NPC is met, or an encounter can sell it itself. Players see what is for
+sale and buy it in an NPC quest that is in progress: the price leaves their
+purse and the item joins their inventory. See [NPCS.md](NPCS.md), section 5,
+and [ENCOUNTERS.md](ENCOUNTERS.md), section 10.
+
 ## 8. Permissions
 
 | Action | DM | Owning player | Other players |
@@ -136,6 +143,8 @@ character's inventory, stacking with any they already hold. See
 | Add, change or remove pool items | Yes | No | No |
 | Give an item from the pool, or take one away | Yes | No | No |
 | Give a held item to another character | Yes | Yes | No |
+| Put an item up for sale | Yes | No | No |
+| Buy an item that is for sale, in a quest in progress | Yes, for any character in it | Yes, if the character is in it | No |
 | Change quantity or level | Yes | No | No |
 | Equip or unequip | Yes | Yes, if the character can use it | No |
 | See a character's inventory | Yes | Yes | Yes |
@@ -146,6 +155,7 @@ character's inventory, stacking with any they already hold. See
 - Armor and shields as items
 - Using up items automatically, charges, and attunement
 - Weight, carrying capacity and containers
-- Prices, buying and selling (record the gold change in the money log)
+- A price on the item itself: a price is set each time it is put up for sale
+- Selling items back (record the gold change in the money log)
 - Swaps as a single step (each side gives separately), and asking the
   recipient to accept

docs/MONSTERS.md

@@ -36,10 +36,10 @@ This describes the code as it stands. The built-in list is
 | Name | Up to 80 characters |
 | AC | Armor Class |
 | Max HP | Hit points each copy starts an encounter with |
-| Speed | In feet. 30 unless set otherwise |
+| Speed | Walking speed in feet. 30 unless set otherwise. Other speeds (fly, swim, climb) go in Notes |
 | Ability scores | STR, DEX, CON, INT, WIS, CHA. 10 unless set otherwise |
 | Attack bonus | Added to the monster's attack roll |
-| Damage | Dice for its main attack, e.g. `1d6+2` |
+| Damage | Dice for its main attack, e.g. `1d6+2`, with the damage type if you like: `1d6+2 necrotic` |
 | Challenge rating | A rough danger rating, e.g. `1/4`, `2` |
 | Special trait | A short note such as "Pack Tactics" |
 | Notes | Anything else: what it attacks with, how it behaves |
@@ -52,21 +52,25 @@ from its scores for display only.
 
 The list is the "Monsters" card on the campaign page (DM only).
 
-- **Adding by hand:** "+ Add Monster" asks for name, AC, max HP, attack bonus
-  and damage. Speed is set to 30 and every ability score to 10; challenge
-  rating, trait and notes are left empty.
+- **Adding by hand:** "+ Add Monster" opens the whole stat block: name,
+  challenge rating, AC, HP, speed, attack bonus, damage, the six ability
+  scores, special trait and notes. Only name, AC and HP must be typed; speed
+  starts at 30, attack bonus at 0 and each ability score at 10.
 - **Adding from the bestiary:** "📚 From Library" copies a complete stat block.
-- **Changing:** there is no edit form (the API accepts changes, but no screen
-  offers them). Remove and re-add, or add from the library.
-- **Removing:** the ✕ button, immediately, with no confirmation. Copies
+- **Changing:** "Edit" on a monster's row opens the same form filled in.
+  Saving changes the template, and copies already in encounters show the new
+  stat block straight away; their current HP is left alone.
+- The list shows each monster's full stat block: the numbers in columns, and
+  its ability scores, trait and notes under its name.
+- **Removing:** the ✕ button, after a confirmation. Copies
   already in encounters stay there with their name and HP, but lose their
   stat block.
 
 ## 4. The built-in bestiary
 
-38 monsters, from harmless to dangerous. Each library row shows challenge
-rating, AC, HP, attack and damage, plus its trait and notes, before you add
-it. Adding copies the monster into your campaign; the copy is yours, and later
+38 monsters, from harmless to dangerous, every one with a complete stat
+block. Each library row shows challenge rating, AC, HP, speed, attack, damage
+and the six ability scores, plus its trait and notes, before you add it. Adding copies the monster into your campaign; the copy is yours, and later
 changes to the library do not affect it.
 
 The full bestiary, weakest first. "Attack" is the bonus added to the
@@ -146,8 +150,9 @@ and its notes.
 This is enforced by the server: stat blocks are never sent to a player's
 browser.
 
-Players do see a monster's exact HP numbers. If you would rather keep those
-secret, that is not currently possible.
+Players see a monster's exact HP numbers unless the campaign setting "Players
+see the exact hit points of monsters and NPCs in encounters" is unticked.
+Then they get the health bar only.
 
 ## 7. Permissions
 
@@ -163,6 +168,7 @@ secret, that is not currently possible.
 ## 8. What is not modelled
 
 - Multiple attacks, spells, legendary actions and resistances (use Notes)
+- Trade: monsters do not sell things or change money (NPCs do)
 - Rolling a monster's attacks or damage (use the dice roller)
 - Saving throw bonuses and skills
 - Experience points for defeating monsters

docs/NPCS.md

@@ -1,7 +1,8 @@
 # NPCs
 
 How non-player characters work in this app: what the DM records about them,
-how they are brought into a scene, and what players can and cannot see.
+how they are brought into a scene, what they sell and the rate they change
+money at, and what players can and cannot see.
 
 This describes the code as it stands. Related: [ENCOUNTERS.md](ENCOUNTERS.md),
 [MONSTERS.md](MONSTERS.md).
@@ -12,10 +13,11 @@ This describes the code as it stands. Related: [ENCOUNTERS.md](ENCOUNTERS.md),
 2. [What an NPC holds](#2-what-an-npc-holds)
 3. [Managing NPCs](#3-managing-npcs)
 4. [NPCs in encounters](#4-npcs-in-encounters)
-5. [What players see](#5-what-players-see)
-6. [NPC or monster?](#6-npc-or-monster)
-7. [Permissions](#7-permissions)
-8. [What is not modelled](#8-what-is-not-modelled)
+5. [Trade: changing money and selling](#5-trade-changing-money-and-selling)
+6. [What players see](#6-what-players-see)
+7. [NPC or monster?](#7-npc-or-monster)
+8. [Permissions](#8-permissions)
+9. [What is not modelled](#9-what-is-not-modelled)
 
 ---
 
@@ -27,6 +29,8 @@ This describes the code as it stands. Related: [ENCOUNTERS.md](ENCOUNTERS.md),
 - An NPC does nothing by sitting in the list. Players meet one when the DM
   **adds it to an encounter**.
 - NPCs are mainly for talking to. Combat stats are optional.
+- An NPC can also **trade**: change gold and cash at a rate of their own, and
+  sell weapons and items (section 5).
 
 ## 2. What an NPC holds
 
@@ -38,9 +42,11 @@ This describes the code as it stands. Related: [ENCOUNTERS.md](ENCOUNTERS.md),
 | Description | What the party can see and knows | Everyone |
 | DM notes | Secrets, motives, what they are hiding | **DM only** |
 | AC | Optional | DM only |
-| HP | Optional. Without it the NPC has no health bar | See section 5 |
+| HP | Optional. Without it the NPC has no health bar | See section 6 |
 | Attack bonus | Optional | DM only |
 | Damage | Optional dice, e.g. `1d6` | DM only |
+| Exchange rate | Optional: so much gold for so much cash (section 5) | Everyone, in an encounter |
+| Wares | Optional: weapons and items for sale, each with a price (section 5) | Everyone, in an encounter |
 
 A new NPC is Neutral unless you choose otherwise.
 
@@ -48,10 +54,14 @@ A new NPC is Neutral unless you choose otherwise.
 
 The NPC list is the "NPCs" card on the campaign page (DM only).
 
-- **Adding:** "+ Add NPC" opens a form with every field above. Only the name
-  is required.
-- **Changing:** there is no edit form. To change an NPC, remove it and add it
-  again (the API accepts changes, but no screen offers them).
+- **Adding:** "+ Add NPC" opens a form with every field above except the
+  exchange rate and wares. Only the name is required.
+- **Trade:** the "Trade" button on an NPC's row opens their exchange rate and
+  their wares (section 5). The row shows a 💱 badge with the rate and a 🛒
+  badge with how many things are for sale.
+- **Changing:** there is no edit form for the other fields. To change them,
+  remove the NPC and add it again (the API accepts changes, but no screen
+  offers them). Removing an NPC removes their wares too.
 - **Removing:** the ✕ button, after a confirmation. This also **removes the
   NPC from every encounter** it was in.
 
@@ -73,7 +83,72 @@ An NPC's card shows its attitude as a coloured badge, its role under its
 name, and its description in full. The DM's card also shows AC, attack,
 damage and the DM notes.
 
-## 5. What players see
+## 5. Trade: changing money and selling
+
+Only the DM sets trade up. Players see it and use it on the encounter page,
+in the "Trade" card. The rules for when trading is open are in
+[ENCOUNTERS.md](ENCOUNTERS.md), section 10: in short, in an **NPC quest that
+is in progress**, never in a battle, and only with an NPC who is in the scene
+and not at 0 HP.
+
+### Changing money
+
+An NPC with an **exchange rate** changes gold into cash ($) and cash into
+gold. The rate is two whole numbers, "this much gold = this much cash", and
+each NPC has their own, so one money changer can be a better deal than
+another.
+
+| Rate | Hand over | Get |
+|---|---|---|
+| 1 gold = $5 | 3 gold | $15 |
+| 1 gold = $5 | $20 | 4 gold |
+| 2 gold = $15 | 6 gold | $45 |
+| 2 gold = $15 | $30 | 4 gold |
+
+- The same rate is used both ways.
+- **Only gold and cash.** Silver and copper are not taken, a gold coin is not
+  broken to make up an amount, and no change is given.
+- What is handed over has to be a whole multiple of that side of the rate: at
+  2 gold = $15, gold goes in twos and cash in fifteens.
+- Both sides go on the character's money log, naming the NPC: "Changed with
+  Vex for $45" and "Changed with Vex from 6 gold".
+- An NPC never runs out of gold or cash to change.
+- To set a rate, type both numbers under "Trade" and press "Save rate".
+  "Stop changing money" clears it. An NPC with no rate does not change money.
+
+### Selling
+
+An NPC's **wares** are weapons and items from the campaign's own pools, each
+put up for sale with:
+
+| Field | What it is |
+|---|---|
+| What | One weapon or item from the pool |
+| Level | The gear level it is handed over at, not below its starting level |
+| Price | For one, in gold, silver, copper or cash |
+| Stock | How many can be bought. Empty means no limit |
+
+- Wares belong to the NPC, not to an encounter: they are on offer in every
+  quest that NPC is in.
+- Buying pays the price from the character's purse, adds the weapon or item
+  to what they hold (stacking with any they already have) and lowers the
+  stock. A price in coins is paid with change, exactly like any other spend;
+  a price in cash takes cash only.
+- At 0 stock a ware shows as sold out and cannot be bought. It stays listed
+  until the DM removes it.
+- The ✕ beside a ware stops it being sold. Things already bought stay bought.
+- "Edit" beside a ware changes its price, the coin (or cash) the price is in,
+  and its stock: restock a sold-out ware, or clear the stock for no limit.
+  What is sold, its level and who sells it cannot be changed; remove the ware
+  and put it up again for that.
+- Removing a weapon or item from the campaign pool removes it from sale
+  everywhere.
+
+A stall or a machine with nobody behind it can sell things too: those wares
+belong to an encounter rather than an NPC, and are set up on the encounter
+page. See [ENCOUNTERS.md](ENCOUNTERS.md), section 10.
+
+## 6. What players see
 
 Players only ever see an NPC through an encounter it is in:
 
@@ -81,6 +156,7 @@ Players only ever see an NPC through an encounter it is in:
 |---|---|
 | Name, role, attitude, description | DM notes |
 | Health bar and conditions, if the NPC has HP | AC, attack bonus, damage |
+| The exchange rate, and everything the NPC has for sale with its price and stock | The NPC list, and wares of NPCs who are not in the scene |
 
 This is enforced by the server, not just hidden on screen: the hidden fields
 are never sent to a player's browser.
@@ -88,7 +164,7 @@ are never sent to a player's browser.
 Changing an NPC's attitude changes what players see straight away, so
 flipping a "Friendly" NPC to "Hostile" is itself a reveal.
 
-## 6. NPC or monster?
+## 7. NPC or monster?
 
 | | NPC | Monster |
 |---|---|---|
@@ -99,11 +175,12 @@ flipping a "Friendly" NPC to "Hostile" is itself a reveal.
 | Combat stats | Optional, basic | Full stat block |
 | Can be in an encounter more than once | No | Yes (a pack of goblins) |
 | Built-in library | No | Yes |
+| Can change money and sell things | Yes | No |
 
 A named villain the party will both talk to and fight works well as an NPC
 with HP, AC, attack and damage filled in.
 
-## 7. Permissions
+## 8. Permissions
 
 | Action | DM | Players |
 |---|---|---|
@@ -111,12 +188,18 @@ with HP, AC, attack and damage filled in.
 | Add or remove NPCs | Yes | No |
 | Add an NPC to an encounter | Yes | No |
 | Change an NPC's HP or conditions in an encounter | Yes | No |
-| See an NPC in an encounter | Everything | Name, role, attitude, description, health bar |
+| See an NPC in an encounter | Everything | Name, role, attitude, description, health bar, exchange rate, wares |
+| Set an NPC's exchange rate | Yes | No |
+| Put things up for sale, or take them down | Yes | No |
+| Change money with an NPC, or buy from one | Yes, for any character in the scene | For their own character in the scene |
 
-## 8. What is not modelled
+## 9. What is not modelled
 
 - Ability scores, saves, skills and spells for NPCs
-- NPC inventory, gold and shops
+- An NPC's own purse: they never run short of gold or cash
+- Selling things to an NPC, haggling, and different rates for buying and
+  selling cash
+- Changing silver or copper for cash
 - Where an NPC is (they are not tied to locations)
 - Relationships, reputation and attitude toward individual characters
 - A record of which NPCs the party has met, outside of encounters

docs/SPELLS.md

@@ -46,15 +46,16 @@ The list is the "Spell List" card on the campaign page (DM only).
 | What it does | One sentence. Shown wherever the spell is shown |
 | Damage | Picked from a list, or "No damage". Fixed; it does not grow |
 | Starting option | Whether a brand-new character may pick it in the builder (section 8) |
+| Revives | Whether it brings back the dead. A character who can cast one may revive a dead ally on their turn in a battle ([ENCOUNTERS.md](ENCOUNTERS.md), section 6). Ticked already on the library's Revivify and Raise Dead |
 | Casting time, range, duration | Stored for library spells but not shown on any screen |
 
 A cantrip is a spell of level 0. The app always calls it a **cantrip**, never
 "level 0" or "level 1".
 
 - **Adding:** by hand with the "+ Add Spell" form (name, level, school,
-  damage and what it does), or from the library.
-- **Changing:** damage (the drop-down in the table) and the starting-option
-  tick box. Name, level, school and description cannot be changed on screen
+  damage, what it does and the two tick boxes), or from the library.
+- **Changing:** damage (the drop-down in the table) and the Revives and
+  starting-option tick boxes. Name, level, school and description cannot be changed on screen
   once created (the API accepts it); remove and re-add instead.
 - **Damage choices:** the drop-down offers "No damage", then 1 to 6, 8 or 10
   dice of d4, d6, d8, d10 or d12 (1d4 up to 10d12), plus the three unusual

docs/WEAPONS.md

@@ -19,7 +19,7 @@ This describes the code as it stands. The formulas live in
 6. [How damage grows](#6-how-damage-grows)
 7. [Attack and damage numbers](#7-attack-and-damage-numbers)
 8. [Starting weapons](#8-starting-weapons)
-9. [Weapons as rewards](#9-weapons-as-rewards)
+9. [Weapons as rewards and for sale](#9-weapons-as-rewards-and-for-sale)
 10. [Permissions](#10-permissions)
 11. [What is not modelled](#11-what-is-not-modelled)
 12. [The complete weapon library](#12-the-complete-weapon-library)
@@ -185,13 +185,20 @@ In the builder's equipment step a new character can pick weapons that are:
 Starting weapons and starting items share the campaign's "starting items"
 allowance. They arrive at level 1, unequipped.
 
-## 9. Weapons as rewards
+## 9. Weapons as rewards and for sale
 
 On an encounter the DM can line up a weapon as a reward, at a chosen level
 (not below its starting level) and quantity, and later award it to a
 character. Awarding adds it to what the character holds, exactly as giving it
 on the sheet would. See [ENCOUNTERS.md](ENCOUNTERS.md).
 
+The DM can also put a weapon **up for sale**, at a level, a price (in gold,
+silver, copper or cash) and an optional stock. An NPC can sell it, wherever
+that NPC is met, or an encounter can sell it itself. Players see what is for
+sale and buy it in an NPC quest that is in progress: the price leaves their
+purse and the weapon joins what they hold, unequipped. See
+[NPCS.md](NPCS.md), section 5, and [ENCOUNTERS.md](ENCOUNTERS.md), section 10.
+
 ## 10. Permissions
 
 | Action | DM | Owning player | Other players |
@@ -201,6 +208,8 @@ on the sheet would. See [ENCOUNTERS.md](ENCOUNTERS.md).
 | Add, change or remove pool entries | Yes | No | No |
 | Give a weapon from the pool, or take one away | Yes | No | No |
 | Give a held weapon to another character | Yes | Yes | No |
+| Put a weapon up for sale | Yes | No | No |
+| Buy a weapon that is for sale, in a quest in progress | Yes, for any character in it | Yes, if the character is in it | No |
 | Change a held weapon's level or quantity | Yes | No | No |
 | Equip or unequip | Yes | Yes, if the character can use it | No |
 | See a character's weapons | Yes | Yes | Yes |
@@ -212,7 +221,7 @@ on the sheet would. See [ENCOUNTERS.md](ENCOUNTERS.md).
 - Range and ammunition
 - Critical hits, advantage, and rolling the attack itself (use the dice roller)
 - Magic bonuses such as +1 weapons (use a higher level or growth instead)
-- Price and weight
+- A price on the weapon itself (a price is set each time it is put up for sale), and weight
 
 ## 12. The complete weapon library
 

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "1.3.0",
+  "version": "1.10.1",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/api/queries.ts

@@ -1,4 +1,4 @@
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { useMutation, useQuery, useQueryClient, type QueryClient } from '@tanstack/react-query';
 import { apiClient } from './client';
 import type {
   BuildOptions,
@@ -7,6 +7,7 @@ import type {
   CampaignMemberSummary,
   CharacterDetail,
   CharacterSummary,
+  Currency,
   DiceMode,
   Encounter,
   EncounterMode,
@@ -17,6 +18,7 @@ import type {
   Monster,
   Note,
   Npc,
+  SaleOffer,
   QuickStats,
   Spell,
   Weapon,
@@ -162,6 +164,28 @@ export function usePatchCharacter(characterId: string) {
   });
 }
 
+// What can be done for a character at 0 HP: enter a death save (what the d20
+// showed), steady them, or — the DM only — set the tallies by hand or bring
+// back the dead.
+export type DeathSaveAction =
+  | { action: 'roll'; roll: number }
+  | { action: 'stabilize' }
+  | { action: 'set'; successes: number; failures: number }
+  | { action: 'revive' };
+
+export function useDeathSave(characterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (data: DeathSaveAction) =>
+      (await apiClient.post<{ character: CharacterDetail }>(`/characters/${characterId}/death-saves`, data)).data.character,
+    onSuccess: (character) => {
+      invalidateCharacter(qc, characterId); // the sheet and its quick stats
+      qc.invalidateQueries({ queryKey: ['encounter'] }); // a character combatant shows the sheet's HP
+      qc.invalidateQueries({ queryKey: ['campaign', character.campaignId, 'characters'] });
+    },
+  });
+}
+
 export function useDeleteCharacter(campaignId: string) {
   const qc = useQueryClient();
   return useMutation({
@@ -172,7 +196,7 @@ export function useDeleteCharacter(campaignId: string) {
 
 // What one character can hand to another. Whatever is given leaves the giver.
 export type Gift =
-  | { kind: 'gold'; amount: number }
+  | { kind: 'gold'; amount: number; currency?: Currency }
   | { kind: 'weapon' | 'item'; id: string; quantity: number }
   | { kind: 'spell'; id: string };
 
@@ -211,6 +235,16 @@ export function useQuickStats(characterId: string | undefined, enabled: boolean)
   });
 }
 
+// Changes `amount` coins of one kind into another at their fixed worth.
+export function useExchangeCoins(characterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (data: { from: Currency; to: Currency; amount: number }) =>
+      (await apiClient.post<{ character: CharacterDetail; received: number }>(`/characters/${characterId}/gold/exchange`, data)).data,
+    onSuccess: () => invalidateCharacter(qc, characterId),
+  });
+}
+
 // --------------------------------------------------------------------------
 // Character build flow
 // --------------------------------------------------------------------------
@@ -388,8 +422,8 @@ export function useGoldLedger(characterId: string | undefined, enabled = true) {
 export function useAdjustGold(characterId: string) {
   const qc = useQueryClient();
   return useMutation({
-    mutationFn: async (data: { amount: number; reason?: string }) =>
-      (await apiClient.post<{ gold: number; transaction: GoldTransaction }>(`/characters/${characterId}/gold`, data)).data,
+    mutationFn: async (data: { amount: number; currency?: Currency; reason?: string }) =>
+      (await apiClient.post<{ transaction: GoldTransaction }>(`/characters/${characterId}/gold`, data)).data,
     onSuccess: () => invalidateCharacter(qc, characterId), // prefix match also refreshes the ledger
   });
 }
@@ -430,9 +464,12 @@ export function usePatchPoolEntry(campaignId: string, pool: Pool) {
       isStartingOption?: boolean;
       damageDice?: string | null;
       damageScaling?: number;
+      revives?: boolean;
       minLevel?: number;
       name?: string;
       description?: string | null;
+      exchangeGold?: number | null;
+      exchangeCash?: number | null;
     }) =>
       (await apiClient.patch(`/campaigns/${campaignId}/${pool}/${id}`, data)).data,
     onSuccess: () => qc.invalidateQueries({ queryKey: ['campaign', campaignId, pool] }),
@@ -503,6 +540,20 @@ export function useCreateMonster(campaignId: string) {
   });
 }
 
+// Changes a monster's stat block. Encounters read it live, so copies already
+// in a scene show the new numbers (their HP stays as it was).
+export function useUpdateMonster(campaignId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async ({ id, ...data }: { id: string } & Partial<Omit<Monster, 'id' | 'campaignId'>>) =>
+      (await apiClient.patch<{ monster: Monster }>(`/campaigns/${campaignId}/monsters/${id}`, data)).data.monster,
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['campaign', campaignId, 'monsters'] });
+      qc.invalidateQueries({ queryKey: ['encounter'] });
+    },
+  });
+}
+
 export function useDeleteMonster(campaignId: string) {
   const qc = useQueryClient();
   return useMutation({
@@ -717,6 +768,29 @@ export function usePatchEncounter(encounterId: string) {
 }
 type EncounterStatusInput = 'PLANNING' | 'ACTIVE' | 'COMPLETE';
 
+// Sets which combatants are marked as targets (an empty list clears them).
+// The DM at any time; a player while their own character is on turn.
+export function useSetTargets(encounterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (participantIds: string[]) => (await apiClient.put(`/encounters/${encounterId}/targets`, { participantIds })).data,
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['encounter', encounterId] }),
+  });
+}
+
+// The character on turn trying to bring a dead ally back; the server decides
+// whether they have the means.
+export function useReviveParticipant(encounterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (participantId: string) => (await apiClient.post(`/encounters/${encounterId}/participants/${participantId}/revive`)).data,
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['encounter', encounterId] });
+      qc.invalidateQueries({ queryKey: ['character'] }); // the revived character's sheet
+    },
+  });
+}
+
 export function useNextTurn(encounterId: string) {
   const qc = useQueryClient();
   return useMutation({
@@ -730,7 +804,7 @@ export function useNextTurn(encounterId: string) {
 // --------------------------------------------------------------------------
 
 export type NewReward =
-  | { type: 'GOLD'; gold: number; note?: string }
+  | { type: 'GOLD'; gold: number; currency?: Currency; note?: string }
   | { type: 'WEAPON'; weaponId: string; quantity?: number; level?: number; note?: string }
   | { type: 'ITEM'; itemId: string; quantity?: number; level?: number; note?: string };
 
@@ -786,6 +860,72 @@ export function useCreateNpc(campaignId: string) {
   });
 }
 
+// --------------------------------------------------------------------------
+// Trade — an NPC's exchange rate and wares are set up by the DM; in a quest
+// in progress, characters in the scene change money and buy
+// --------------------------------------------------------------------------
+
+export type NewWare = ({ npcId: string } | { encounterId: string }) &
+  ({ weaponId: string } | { itemId: string }) & { price: number; currency: Currency; level?: number; stock: number | null };
+
+// Wares reach the screen inside the NPC list and inside each encounter.
+function invalidateWares(qc: QueryClient, campaignId: string) {
+  qc.invalidateQueries({ queryKey: ['campaign', campaignId, 'npcs'] });
+  qc.invalidateQueries({ queryKey: ['encounter'] });
+}
+
+export function useCreateWare(campaignId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (data: NewWare) => (await apiClient.post<{ ware: SaleOffer }>(`/campaigns/${campaignId}/wares`, data)).data.ware,
+    onSuccess: () => invalidateWares(qc, campaignId),
+  });
+}
+
+// The price and what is left can change; what is sold, and by whom, cannot.
+export function usePatchWare(campaignId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async ({ id, ...data }: { id: string; price?: number; currency?: Currency; stock?: number | null }) =>
+      (await apiClient.patch<{ ware: SaleOffer }>(`/campaigns/${campaignId}/wares/${id}`, data)).data.ware,
+    onSuccess: () => invalidateWares(qc, campaignId),
+  });
+}
+
+export function useDeleteWare(campaignId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (wareId: string) => apiClient.delete(`/campaigns/${campaignId}/wares/${wareId}`),
+    onSuccess: () => invalidateWares(qc, campaignId),
+  });
+}
+
+// Both change what a character holds, so the sheet and the party list refresh too.
+function invalidateAfterTrade(qc: QueryClient, encounterId: string) {
+  qc.invalidateQueries({ queryKey: ['encounter', encounterId] });
+  qc.invalidateQueries({ queryKey: ['character'] });
+  qc.invalidateQueries({ queryKey: ['campaign'] });
+}
+
+// Changes gold into cash or cash into gold with an NPC in the scene, at their rate.
+export function useExchangeWithNpc(encounterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (data: { characterId: string; npcId: string; from: 'GOLD' | 'CASH'; amount: number }) =>
+      (await apiClient.post<{ received: number; currency: Currency }>(`/encounters/${encounterId}/exchange`, data)).data,
+    onSuccess: () => invalidateAfterTrade(qc, encounterId),
+  });
+}
+
+export function useBuyWare(encounterId: string) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async ({ wareId, ...data }: { wareId: string; characterId: string; quantity?: number }) =>
+      (await apiClient.post(`/encounters/${encounterId}/wares/${wareId}/buy`, data)).data,
+    onSuccess: () => invalidateAfterTrade(qc, encounterId),
+  });
+}
+
 // --------------------------------------------------------------------------
 // Notes
 // --------------------------------------------------------------------------

frontend/src/api/types.ts

@@ -93,6 +93,8 @@ export interface Campaign {
   startingSpellCount: number;
   skipMotivationRoll: boolean;
   showMonsterHp: boolean; // off: players get a health bar for monsters and NPCs, no numbers
+  // Added to each target's AC for every target beyond the first in an area attack; 0 is off.
+  areaAttackAcPenalty: number;
   ownerId: string;
   archivedAt: string | null; // set while the campaign is archived
   role: 'DM' | 'PLAYER';
@@ -105,6 +107,22 @@ export interface CampaignMemberSummary {
   role: 'DM' | 'PLAYER';
 }
 
+// The coins a character carries. 1 gold = 10 silver = 100 copper.
+export type Coin = 'GOLD' | 'SILVER' | 'COPPER';
+// Coins, plus cash ($): modern money for crossover worlds, with no worth in coins.
+export type Currency = Coin | 'CASH';
+
+// Where a character stands at 0 HP. UP: on their feet. DYING: rolling death
+// saves, three of either kind settles it. STABLE: at 0 HP but no longer
+// rolling. DEAD: three failures, or one blow too big to survive.
+export type LifeState = 'UP' | 'DYING' | 'STABLE' | 'DEAD';
+
+export interface DeathSaves {
+  state: LifeState;
+  successes: number;
+  failures: number;
+}
+
 export interface CharacterSummary {
   id: string;
   campaignId: string;
@@ -118,7 +136,12 @@ export interface CharacterSummary {
   buildStage: BuildStage;
   currentHp: number;
   tempHp: number;
-  gold: number | null; // null for another player's character
+  deathSaves: DeathSaves;
+  // The purse; all four are null for another player's character.
+  gold: number | null;
+  silver: number | null;
+  copper: number | null;
+  cash: number | null;
   maxHp: number | null;
   armorClass: number | null;
   currentLocationId: string | null;
@@ -195,6 +218,7 @@ export interface Spell {
   description: string | null;
   damageDice: string | null;
   isStartingOption: boolean;
+  revives: boolean; // brings back the dead: lets its caster revive a dead ally in a battle
 }
 
 export interface CharacterSpell {
@@ -233,8 +257,9 @@ export interface InventoryItem {
 export interface GoldTransaction {
   id: string;
   characterId: string;
+  currency: Currency; // which coin this entry is in
   amount: number; // signed: positive = gained, negative = spent
-  balanceAfter: number;
+  balanceAfter: number; // that coin's balance afterwards
   reason: string | null;
   createdAt: string;
   createdBy: { displayName: string } | null;
@@ -267,6 +292,7 @@ export interface CharacterDetail {
   rolledScores: Record<Ability, number>;
   currentHp: number;
   tempHp: number;
+  deathSaves: DeathSaves;
   armorBonus: number;
   specialAbilities: string | null;
   background: string | null;
@@ -278,6 +304,9 @@ export interface CharacterDetail {
   currentLocationId: string | null;
   currentLocation: Location | null;
   gold: number | null;
+  silver: number | null;
+  copper: number | null;
+  cash: number | null;
   // True when this is another player's character: no gold, inventory or
   // location is sent, only what the party can see across the table.
   restricted: boolean;
@@ -315,6 +344,23 @@ export type EncounterStatus = 'PLANNING' | 'ACTIVE' | 'COMPLETE';
 export type EncounterMode = 'BATTLE' | 'QUEST';
 export type NpcDisposition = 'FRIENDLY' | 'NEUTRAL' | 'HOSTILE';
 
+// Something for sale: a weapon or item from the campaign pools, at a price.
+// It is an NPC's (on offer wherever they are met) or an encounter's own.
+export interface SaleOffer {
+  id: string;
+  campaignId: string;
+  npcId: string | null;
+  encounterId: string | null;
+  weaponId: string | null;
+  itemId: string | null;
+  price: number; // for one, in `currency`
+  currency: Currency;
+  level: number; // the gear level it is handed over at
+  stock: number | null; // how many are left; null is no limit
+  weapon: Weapon | null;
+  item: Item | null;
+}
+
 // What players see of an NPC in an encounter.
 export interface NpcPublic {
   id: string;
@@ -322,6 +368,11 @@ export interface NpcPublic {
   role: string | null;
   disposition: NpcDisposition;
   description: string | null;
+  // A money changer's rate: exchangeGold gold for exchangeCash cash, either
+  // way. Both null for an NPC who does not change money.
+  exchangeGold: number | null;
+  exchangeCash: number | null;
+  wares?: SaleOffer[]; // what they have for sale
 }
 
 // The DM's full record. dmNotes and the combat stats never reach a player.
@@ -337,7 +388,8 @@ export interface EncounterReward {
   id: string;
   encounterId: string;
   type: 'GOLD' | 'WEAPON' | 'ITEM';
-  gold: number | null;
+  gold: number | null; // for a GOLD reward: how many coins...
+  currency: Currency; // ...and which coin
   weaponId: string | null;
   itemId: string | null;
   quantity: number;
@@ -376,6 +428,8 @@ export interface CharacterCombatInfo {
   characterClass: CharacterClass | null;
   armorClass: number;
   tempHp: number;
+  deathSaves: DeathSaves;
+  canRevive: boolean; // has a spell that brings back the dead, at a level they can cast
   speed: number;
   initiativeBonus: number;
   passivePerception: number;
@@ -407,6 +461,9 @@ export interface EncounterParticipant {
   conditions: string[];
   isMonster: boolean;
   kind: 'CHARACTER' | 'MONSTER' | 'NPC';
+  // Out of the fight (a dead character, or a monster or NPC at 0 HP) and so
+  // hidden from the players. Only the DM is ever sent one of these.
+  hidden: boolean;
   npcId: string | null;
   character?: { id: string; name: string; userId: string | null } | null;
   // The DM gets the whole stat block; players only the id and name.
@@ -423,6 +480,9 @@ export interface Encounter {
   status: EncounterStatus;
   currentRound: number;
   activeParticipantId: string | null;
+  // The combatants marked as targets right now, for everyone to see, in the
+  // order they were picked. More than one is an area attack.
+  targetParticipantIds: string[];
   description: string | null;
   dmNotes?: string | null; // DM only
   // Where the scene is. A player is only told once their character has been there.
@@ -431,8 +491,12 @@ export interface Encounter {
   archivedAt: string | null; // archived encounters only reach the DM's list
   sortOrder: number; // place in the campaign's own order, lowest first
   createdAt: string;
-  participants?: EncounterParticipant[];
+  participants?: EncounterParticipant[]; // a player's list leaves out the fallen
+  // The dead characters in the scene. Players do not get their cards, only
+  // this, so that an ally can try to revive them.
+  fallen?: { participantId: string; characterId: string; name: string }[];
   rewards?: EncounterReward[]; // players only receive the awarded ones
+  wares?: SaleOffer[]; // for sale at the scene itself, not by an NPC in it
 }
 
 export interface Note {
@@ -468,6 +532,7 @@ export interface LibrarySpell {
   duration: string | null;
   description: string | null;
   damageDice?: string; // default damage; absent for spells that deal none
+  revives?: boolean; // brings back the dead
   classes: CharacterClass[];
 }
 
@@ -514,6 +579,7 @@ export interface QuickStats {
   currentHp: number;
   maxHp: number;
   tempHp: number;
+  deathSaves: DeathSaves;
   armorClass: number;
   initiative: number;
   speed: number;

frontend/src/components/DeathSaves.tsx

@@ -0,0 +1,118 @@
+import { useState } from 'react';
+import { useDeathSave } from '../api/queries';
+import { InfoTip } from './InfoTip';
+import { NumberInput } from './NumberInput';
+import type { DeathSaves as DeathSavesInfo } from '../api/types';
+
+const STATE_LABELS = { DYING: 'Dying', STABLE: 'Stable', DEAD: '☠ Dead' } as const;
+
+// Nothing for a character on their feet; otherwise where they stand at 0 HP.
+export function LifeBadge({ deathSaves }: { deathSaves: DeathSavesInfo }) {
+  if (deathSaves.state === 'UP') return null;
+  return <span className={`badge ${deathSaves.state === 'STABLE' ? '' : 'badge-hostile'}`}>{STATE_LABELS[deathSaves.state]}</span>;
+}
+
+// Three pips for one tally. For the DM each is a button: clicking a pip sets
+// the tally to it, and clicking the last filled one takes it back off.
+function Pips({ kind, count, onSet }: { kind: 'success' | 'failure'; count: number; onSet?: (count: number) => void }) {
+  const noun = kind === 'success' ? 'successes' : 'failures';
+  return (
+    <span className="death-pips" role="group" aria-label={`${count} of 3 ${noun}`}>
+      {[1, 2, 3].map((n) => {
+        const className = `death-pip is-${kind}${n <= count ? ' is-filled' : ''}`;
+        return onSet ? (
+          <button key={n} type="button" className={className} aria-label={`Set ${noun} to ${n === count ? n - 1 : n}`} onClick={() => onSet(n === count ? n - 1 : n)} />
+        ) : (
+          <span key={n} className={className} />
+        );
+      })}
+    </span>
+  );
+}
+
+// What happens to a character at 0 HP: the death-save tallies, and the ways
+// out of them. `canAct` is the character's own player or the DM; setting the
+// tallies by hand and raising the dead from here are the DM's alone.
+export function DeathSaves({
+  characterId,
+  name,
+  deathSaves,
+  canAct,
+  isDM,
+  onError,
+}: {
+  characterId: string;
+  name: string;
+  deathSaves: DeathSavesInfo;
+  canAct: boolean;
+  isDM: boolean;
+  onError?: (err: unknown) => void;
+}) {
+  const deathSave = useDeathSave(characterId);
+  const [roll, setRoll] = useState('');
+  const { state, successes, failures } = deathSaves;
+  if (state === 'UP') return null;
+
+  const send = (action: Parameters<typeof deathSave.mutate>[0]) => deathSave.mutate(action, { onError });
+
+  function handleRoll() {
+    const value = Number(roll);
+    if (!roll || !Number.isInteger(value)) return;
+    send({ action: 'roll', roll: value });
+    setRoll('');
+  }
+
+  return (
+    <div className={`death-saves is-${state.toLowerCase()}`}>
+      <div className="flex-row flex-wrap">
+        <LifeBadge deathSaves={deathSaves} />
+        {state === 'DYING' && (
+          <>
+            <span className="death-tally">
+              Saved <Pips kind="success" count={successes} onSet={isDM ? (n) => send({ action: 'set', successes: n, failures }) : undefined} />
+            </span>
+            <span className="death-tally">
+              Failed <Pips kind="failure" count={failures} onSet={isDM ? (n) => send({ action: 'set', successes, failures: n }) : undefined} />
+            </span>
+            <InfoTip term="DEATH_SAVES" />
+          </>
+        )}
+        {state === 'STABLE' && <span className="combatant-sub">Out cold at 0 HP, but no longer rolling. Any healing wakes them; damage starts the saves again.</span>}
+        {state === 'DEAD' && <span className="combatant-sub">{isDM ? 'Healing does nothing now.' : 'The DM can bring them back, or an ally with a reviving spell on their turn in a battle.'}</span>}
+      </div>
+
+      {state === 'DYING' && canAct && (
+        <div className="flex-row flex-wrap gap-sm mt-sm">
+          <NumberInput
+            min={1}
+            max={20}
+            placeholder="d20"
+            aria-label={`Death save roll for ${name}`}
+            title="Type what the d20 showed (1 to 20)."
+            value={roll}
+            onChange={(e) => setRoll(e.target.value)}
+            onKeyDown={(e) => e.key === 'Enter' && handleRoll()}
+            style={{ width: 64 }}
+          />
+          <button className="btn" onClick={handleRoll} disabled={!roll || deathSave.isPending}>
+            Death save
+          </button>
+          <button
+            className="btn btn-ghost"
+            title="Someone steadied them: a Medicine check, a healer's kit or a spell. They stay at 0 HP but stop rolling."
+            onClick={() => send({ action: 'stabilize' })}
+            disabled={deathSave.isPending}
+          >
+            Stabilise
+          </button>
+        </div>
+      )}
+
+      {state === 'DEAD' && isDM && (
+        <button className="btn mt-sm" onClick={() => send({ action: 'revive' })} disabled={deathSave.isPending}>
+          Revive at 1 HP
+        </button>
+      )}
+    </div>
+  );
+}

frontend/src/components/InfoTip.tsx

@@ -1,4 +1,5 @@
-import { useId, useState } from 'react';
+import { useEffect, useId, useRef, useState, type CSSProperties } from 'react';
+import { createPortal } from 'react-dom';
 
 // Short explanations for the stat labels sprinkled across the sheet, quick
 // stats, party table, and builder — "what is this, and how is it worked
@@ -7,6 +8,7 @@ export const STAT_HELP: Record<string, string> = {
   AC: 'Armor Class — how hard you are to hit. 10 + your Dexterity modifier + any armor bonus.',
   HP: 'Hit Points — damage you can take before falling unconscious. Max HP is set by your class hit die, Constitution modifier, and level.',
   TEMP_HP: 'Temporary Hit Points — an extra buffer that absorbs damage first and disappears when it runs out (it does not stack with more temp HP).',
+  DEATH_SAVES: 'Death saves — at 0 HP you roll a d20 at the start of each of your turns. 10 or more is a success, less is a failure; a 1 counts as two failures and a 20 puts you back up with 1 HP. Three successes and you are stable; three failures and you die. Being hit while down is a failure (two if it was a critical hit). Any healing ends it.',
   INITIATIVE: 'Initiative — added to a d20 roll at the start of a fight to decide turn order. Equal to your Dexterity modifier.',
   PROFICIENCY_BONUS: 'Proficiency Bonus — added to attacks, saves, and skills you are trained in. Grows with level (+2 at level 1, up to +6 at level 20).',
   PASSIVE_PERCEPTION: 'Passive Perception — your always-on alertness score, used instead of rolling when you are not actively searching. 10 + your Perception skill bonus.',
@@ -38,8 +40,36 @@ export const STAT_HELP: Record<string, string> = {
 // (a species, a skill, an ability) without adding it to the shared list.
 export function InfoTip({ term, text: custom, label = 'What is this?' }: { term?: keyof typeof STAT_HELP; text?: string; label?: string }) {
   const [open, setOpen] = useState(false);
+  const [place, setPlace] = useState<CSSProperties | null>(null);
+  const trigger = useRef<HTMLButtonElement>(null);
   const id = useId();
   const text = custom ?? (term ? STAT_HELP[term] : undefined);
+
+  // The bubble is drawn on the page itself, fixed to where the ⓘ is on
+  // screen, rather than inside whatever holds the ⓘ: a scrolling table or a
+  // drawer would otherwise cut it off. It sits above the ⓘ when there is room
+  // and below when there isn't, and never runs off the sides.
+  useEffect(() => {
+    if (!open || !trigger.current) return;
+    const rect = trigger.current.getBoundingClientRect();
+    const halfWidth = Math.min(130, window.innerWidth / 2 - 8);
+    const centre = Math.min(Math.max(rect.left + rect.width / 2, halfWidth + 8), window.innerWidth - halfWidth - 8);
+    const above = rect.top > 160;
+    setPlace({
+      left: centre,
+      ...(above ? { bottom: window.innerHeight - rect.top + 8 } : { top: rect.bottom + 8 }),
+    });
+    // Its position is only right until the page moves.
+    const close = () => setOpen(false);
+    window.addEventListener('scroll', close, true);
+    window.addEventListener('resize', close);
+    return () => {
+      window.removeEventListener('scroll', close, true);
+      window.removeEventListener('resize', close);
+      setPlace(null); // so the next opening is measured afresh, not shown where the last one was
+    };
+  }, [open]);
+
   if (!text) return null;
 
   return (
@@ -49,6 +79,7 @@ export function InfoTip({ term, text: custom, label = 'What is this?' }: { term?
         className="info-tip-trigger"
         aria-describedby={id}
         aria-label={label}
+        ref={trigger}
         onMouseEnter={() => setOpen(true)}
         onFocus={() => setOpen(true)}
         onBlur={() => setOpen(false)}
@@ -56,11 +87,14 @@ export function InfoTip({ term, text: custom, label = 'What is this?' }: { term?
       >
         ⓘ
       </button>
-      {open && (
-        <span role="tooltip" id={id} className="info-tip-bubble">
-          {text}
-        </span>
-      )}
+      {open &&
+        place &&
+        createPortal(
+          <span role="tooltip" id={id} className="info-tip-bubble" style={place}>
+            {text}
+          </span>,
+          document.body,
+        )}
     </span>
   );
 }

frontend/src/components/JumpNav.tsx

@@ -0,0 +1,36 @@
+import { useEffect, useState } from 'react';
+
+// A row of links to the sections of a long page. It finds them itself: any
+// element with a `data-jump="Label"` attribute that is on the page right now
+// gets a link, so sections only some people see need no special handling.
+export function JumpNav() {
+  const [labels, setLabels] = useState<string[]>([]);
+
+  // Sections come and go as data loads, so the page is watched for them.
+  useEffect(() => {
+    const look = () => {
+      const found = [...document.querySelectorAll<HTMLElement>('[data-jump]')].map((el) => el.dataset.jump ?? '');
+      setLabels((current) => (current.join('|') === found.join('|') ? current : found));
+    };
+    const observer = new MutationObserver(look);
+    observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['data-jump'] });
+    look();
+    return () => observer.disconnect();
+  }, []);
+
+  if (labels.length < 3) return null;
+  return (
+    <nav className="jump-nav" aria-label="Sections of this page">
+      {labels.map((label) => (
+        <button
+          key={label}
+          type="button"
+          className="jump-link"
+          onClick={() => document.querySelector(`[data-jump="${label}"]`)?.scrollIntoView({ behavior: 'smooth', block: 'start' })}
+        >
+          {label}
+        </button>
+      ))}
+    </nav>
+  );
+}

frontend/src/components/Layout.tsx

@@ -1,10 +1,39 @@
-import { Link, Outlet } from 'react-router-dom';
+import { Link, NavLink, Outlet, useMatch } from 'react-router-dom';
 import { useAuth } from '../auth/AuthContext';
+import { useLastCampaignId, useRememberCampaign } from '../lib/lastCampaign';
 import { DiceRoller } from './DiceRoller';
 
 export function Layout() {
   const { user, logout } = useAuth();
 
+  // The campaign pages say which campaign they are in their address; sheets
+  // and encounters report theirs themselves (useRememberCampaign).
+  const onCampaign = useMatch('/campaigns/:campaignId/*');
+  useRememberCampaign(onCampaign?.params.campaignId);
+  const campaignId = useLastCampaignId();
+
+  // The same destinations twice: along the top bar on a wide screen, and as a
+  // bar along the bottom, in reach of a thumb, on a phone.
+  const destinations = [
+    { to: '/campaigns', end: true, icon: '🗺', label: 'Campaigns' },
+    ...(campaignId
+      ? [
+          { to: `/campaigns/${campaignId}`, end: true, icon: '🏰', label: 'Campaign' },
+          { to: `/campaigns/${campaignId}/party`, end: true, icon: '👥', label: 'Party' },
+        ]
+      : []),
+    { to: '/account', end: true, icon: '👤', label: 'Account' },
+  ];
+  const links = (className: string) =>
+    destinations.map((d) => (
+      <NavLink key={d.to} to={d.to} end={d.end} className={({ isActive }) => `${className}${isActive ? ' is-active' : ''}`}>
+        <span className="nav-icon" aria-hidden>
+          {d.icon}
+        </span>
+        <span>{d.label}</span>
+      </NavLink>
+    ));
+
   return (
     <div className="app-shell">
       <header className="topbar">
@@ -14,22 +43,26 @@ export function Layout() {
           </span>
           The Sunken Reach
         </Link>
-        <nav className="topbar-nav">
-          {user && (
+        {user && (
+          <nav className="topbar-nav" aria-label="Main">
+            <div className="topbar-links">{links('topbar-link')}</div>
             <div className="topbar-user">
-              <Link to="/account" title="Account settings">
-                {user.displayName}
-              </Link>
+              <span className="topbar-name">{user.displayName}</span>
               <button className="btn btn-ghost" onClick={logout}>
                 Log out
               </button>
             </div>
-          )}
-        </nav>
+          </nav>
+        )}
       </header>
       <main className="page">
         <Outlet />
       </main>
+      {user && (
+        <nav className="bottom-nav" aria-label="Main">
+          {links('bottom-nav-link')}
+        </nav>
+      )}
       <DiceRoller />
     </div>
   );

frontend/src/components/QuickStatsDrawer.tsx

@@ -3,6 +3,7 @@ import { useQuickStats } from '../api/queries';
 import { Spinner, ErrorBanner } from './Spinner';
 import { fmtMod } from '../lib/format';
 import { HpBar } from './HpBar';
+import { DeathSaves } from './DeathSaves';
 
 export function QuickStatsFab({ characterId }: { characterId: string }) {
   const [open, setOpen] = useState(false);
@@ -52,6 +53,8 @@ export function QuickStatsDrawer({ characterId, onClose }: { characterId: string
               </div>
             </div>
             <HpBar current={data.currentHp} max={data.maxHp} temp={data.tempHp} />
+            {/* Read-only here; the saves are rolled on the sheet or in the encounter. */}
+            <DeathSaves characterId={characterId} name={data.name} deathSaves={data.deathSaves} canAct={false} isDM={false} />
 
             {data.spellcasting && (
               <div className="card mt-md">

frontend/src/components/TradePanel.tsx

@@ -0,0 +1,196 @@
+import { useState } from 'react';
+import { Link } from 'react-router-dom';
+import { useBuyWare, useExchangeWithNpc } from '../api/queries';
+import { NumberInput } from './NumberInput';
+import { WaresEditor } from './Wares';
+import { stockLabel, wareName } from '../lib/wares';
+import { formatMoney, formatPurse } from '../lib/format';
+import type { CharacterSummary, Encounter, Item, SaleOffer, Weapon } from '../api/types';
+
+type ExchangeSide = 'GOLD' | 'CASH';
+
+// Trade in a quest: changing gold and cash with an NPC who does that, at
+// their own rate, and buying what the NPCs in the scene — or the scene itself
+// — have for sale. Everyone sees what is on offer; a player trades for their
+// own character, the DM for anyone. Trading is open only while the quest is in
+// progress, and there is none in a battle. The DM sets it all up: an NPC's
+// rate and wares on the campaign page, the scene's own wares here.
+export function TradePanel({
+  encounter,
+  isDM,
+  userId,
+  characters,
+  weapons,
+  items,
+  onError,
+}: {
+  encounter: Encounter;
+  isDM: boolean;
+  userId: string | undefined;
+  characters: CharacterSummary[];
+  weapons: Weapon[];
+  items: Item[];
+  onError: (err: unknown) => void;
+}) {
+  const exchange = useExchangeWithNpc(encounter.id);
+  const buy = useBuyWare(encounter.id);
+
+  const [traderId, setTraderId] = useState('');
+  const [amounts, setAmounts] = useState<Record<string, string>>({});
+  const [sides, setSides] = useState<Record<string, ExchangeSide>>({});
+  const [done, setDone] = useState<string | null>(null);
+
+  if (encounter.mode !== 'QUEST') return null;
+
+  const here = (encounter.participants ?? []).filter((p) => !p.hidden);
+  const npcs = here.flatMap((p) => (p.npc ? [p.npc] : []));
+  const changers = npcs.filter((npc) => npc.exchangeGold && npc.exchangeCash);
+  const stalls: [string, string, SaleOffer[]][] = [
+    ...npcs.map((npc): [string, string, SaleOffer[]] => [npc.id, `${npc.name} sells`, npc.wares ?? []]),
+    ['here', 'For sale here', encounter.wares ?? []],
+  ];
+  const openStalls = stalls.filter(([, , wares]) => wares.length > 0);
+  if (!isDM && changers.length === 0 && openStalls.length === 0) return null;
+
+  // Who can do the trading: a player's own characters in the scene, or for the DM anyone's.
+  const traders = here.flatMap((p) => (p.character && (isDM || p.character.userId === userId) ? [p.character] : []));
+  const trader = traders.find((c) => c.id === traderId) ?? traders[0];
+  const purse = characters.find((c) => c.id === trader?.id);
+  const open = encounter.status === 'ACTIVE';
+  const busy = exchange.isPending || buy.isPending;
+
+  function handleExchange(npc: (typeof changers)[number]) {
+    const from = sides[npc.id] ?? 'GOLD';
+    const amount = Math.floor(Number(amounts[npc.id]));
+    if (!trader || !(amount > 0)) return;
+    setDone(null);
+    exchange.mutate(
+      { characterId: trader.id, npcId: npc.id, from, amount },
+      {
+        onError,
+        onSuccess: ({ received, currency }) => {
+          setDone(`${trader.name} changed ${formatMoney(amount, from, true)} for ${formatMoney(received, currency, true)} with ${npc.name}.`);
+          setAmounts((a) => ({ ...a, [npc.id]: '' }));
+        },
+      }
+    );
+  }
+
+  function handleBuy(ware: SaleOffer) {
+    if (!trader) return;
+    setDone(null);
+    buy.mutate(
+      { wareId: ware.id, characterId: trader.id },
+      { onError, onSuccess: () => setDone(`${trader.name} bought ${(ware.weapon ?? ware.item)?.name} for ${formatMoney(ware.price, ware.currency, true)}.`) }
+    );
+  }
+
+  return (
+    <div className="card">
+      <div className="card-title">Trade</div>
+      {!open && (
+        <p className="combatant-sub" style={{ marginTop: 0 }}>
+          {encounter.status === 'PLANNING' ? 'Trading opens once the quest is in progress.' : 'The quest is over; trading is closed.'}
+        </p>
+      )}
+      {traders.length > 0 && (
+        <div className="flex-row flex-wrap gap-sm">
+          <select aria-label="Who is trading" value={trader?.id ?? ''} onChange={(e) => setTraderId(e.target.value)} style={{ flex: 1, minWidth: 110 }}>
+            {traders.map((c) => (
+              <option key={c.id} value={c.id}>
+                {c.name}
+              </option>
+            ))}
+          </select>
+          {purse && purse.gold !== null && <span className="mono">{formatPurse(purse)}</span>}
+        </div>
+      )}
+      {traders.length === 0 && (changers.length > 0 || openStalls.length > 0) && (
+        <p className="combatant-sub">{isDM ? 'Add a character to the scene to trade for them.' : 'Your character has to be in the scene to trade.'}</p>
+      )}
+      {done && <p className="combatant-sub">✓ {done}</p>}
+
+      {changers.map((npc) => {
+        const from = sides[npc.id] ?? 'GOLD';
+        const to = from === 'GOLD' ? 'CASH' : 'GOLD';
+        const rate = { GOLD: npc.exchangeGold ?? 1, CASH: npc.exchangeCash ?? 1 };
+        const amount = Math.floor(Number(amounts[npc.id]));
+        const whole = amount > 0 && amount % rate[from] === 0;
+        return (
+          <div key={npc.id} className="reward-row">
+            <strong>💱 {npc.name}</strong>
+            <span className="combatant-sub">
+              {' '}
+              changes {formatMoney(rate.GOLD, 'GOLD', true)} for {formatMoney(rate.CASH, 'CASH')}, either way. No silver or copper.
+            </span>
+            <div className="flex-row flex-wrap gap-sm mt-sm">
+              <NumberInput
+                min={1}
+                max={1000000}
+                placeholder="Amount"
+                aria-label={`How much to change with ${npc.name}`}
+                value={amounts[npc.id] ?? ''}
+                onChange={(e) => setAmounts((a) => ({ ...a, [npc.id]: e.target.value }))}
+                style={{ width: 90 }}
+              />
+              <select
+                aria-label={`What to hand ${npc.name}`}
+                value={from}
+                onChange={(e) => setSides((s) => ({ ...s, [npc.id]: e.target.value as ExchangeSide }))}
+              >
+                <option value="GOLD">gold into cash</option>
+                <option value="CASH">cash into gold</option>
+              </select>
+              <button className="btn" disabled={!open || !trader || !whole || busy} onClick={() => handleExchange(npc)}>
+                {whole ? `Get ${formatMoney((amount / rate[from]) * rate[to], to, true)}` : 'Exchange'}
+              </button>
+            </div>
+            {amount > 0 && !whole && (
+              <div className="combatant-sub">
+                Hand over {from.toLowerCase()} in multiples of {rate[from]}.
+              </div>
+            )}
+          </div>
+        );
+      })}
+
+      {openStalls.map(([key, label, wares]) => (
+        <div key={key} className="mt-sm">
+          <div className="section-label">🛒 {label}</div>
+          {wares.map((ware) => (
+            <div key={ware.id} className="reward-row">
+              <div className="flex-between">
+                <span>
+                  <strong>{wareName(ware)}</strong>
+                  <span className="combatant-sub"> · {stockLabel(ware)}</span>
+                </span>
+                <button className="btn" disabled={!open || !trader || ware.stock === 0 || busy} onClick={() => handleBuy(ware)}>
+                  Buy · {formatMoney(ware.price, ware.currency)}
+                </button>
+              </div>
+              {ware.item?.description && <div className="combatant-sub">{ware.item.description}</div>}
+            </div>
+          ))}
+        </div>
+      ))}
+
+      {isDM && (
+        <div className="mt-md">
+          <div className="section-label">Set up: for sale at this encounter</div>
+          <p className="combatant-sub" style={{ marginTop: 0 }}>
+            For a stall or a machine with nobody behind it. An NPC's wares and exchange rate are set under "Trade" on the{' '}
+            <Link to={`/campaigns/${encounter.campaignId}`}>campaign page</Link>, and follow the NPC into every quest.
+          </p>
+          <WaresEditor
+            campaignId={encounter.campaignId}
+            seller={{ encounterId: encounter.id }}
+            wares={encounter.wares ?? []}
+            weapons={weapons}
+            items={items}
+            onError={onError}
+          />
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/components/Wares.tsx

@@ -0,0 +1,204 @@
+import { useState } from 'react';
+import { useCreateWare, useDeleteWare, usePatchWare } from '../api/queries';
+import { NumberInput } from './NumberInput';
+import { COIN_LABELS, CURRENCIES, formatMoney } from '../lib/format';
+import { scaledDamageDice, MAX_GEAR_LEVEL } from '../lib/previewCalc';
+import { stockLabel, wareName } from '../lib/wares';
+import type { Currency, Item, SaleOffer, Weapon } from '../api/types';
+
+// One ware in the DM's list. "Edit" swaps the line for its price and stock.
+function WareRow({ campaignId, ware, onError }: { campaignId: string; ware: SaleOffer; onError: (err: unknown) => void }) {
+  const patchWare = usePatchWare(campaignId);
+  const deleteWare = useDeleteWare(campaignId);
+  const [editing, setEditing] = useState(false);
+  const [price, setPrice] = useState('');
+  const [currency, setCurrency] = useState<Currency>(ware.currency);
+  const [stock, setStock] = useState('');
+
+  function startEditing() {
+    setPrice(String(ware.price));
+    setCurrency(ware.currency);
+    setStock(ware.stock === null ? '' : String(ware.stock));
+    setEditing(true);
+  }
+
+  function handleSave() {
+    const amount = Math.floor(Number(price));
+    if (!(amount > 0)) return;
+    patchWare.mutate({ id: ware.id, price: amount, currency, stock: stock === '' ? null : Number(stock) }, { onError, onSuccess: () => setEditing(false) });
+  }
+
+  return (
+    <div style={{ padding: '0.3rem 0', borderBottom: '1px solid var(--border-soft)' }}>
+      <div className="flex-between">
+        <span>
+          {wareName(ware)} — <strong className="mono">{formatMoney(ware.price, ware.currency)}</strong>
+          <span className="combatant-sub"> · {stockLabel(ware)}</span>
+        </span>
+        <span className="flex-row">
+          <button className="btn btn-ghost" aria-label={`Edit the price and stock of ${wareName(ware)}`} onClick={() => (editing ? setEditing(false) : startEditing())}>
+            {editing ? 'Cancel' : 'Edit'}
+          </button>
+          <button className="btn btn-ghost" aria-label={`Stop selling ${wareName(ware)}`} onClick={() => deleteWare.mutate(ware.id, { onError })}>
+            ✕
+          </button>
+        </span>
+      </div>
+      {editing && (
+        <div className="flex-row flex-wrap gap-sm mt-sm">
+          <NumberInput min={1} max={1000000} placeholder="Price" aria-label="Price for one" value={price} onChange={(e) => setPrice(e.target.value)} style={{ width: 90 }} />
+          <select aria-label="Price is in" value={currency} onChange={(e) => setCurrency(e.target.value as Currency)}>
+            {CURRENCIES.map((c) => (
+              <option key={c} value={c}>
+                {COIN_LABELS[c]}
+              </option>
+            ))}
+          </select>
+          <NumberInput
+            min={0}
+            max={9999}
+            placeholder="Stock (empty = no limit)"
+            aria-label="How many are in stock"
+            title="How many can be bought. Leave empty for no limit."
+            value={stock}
+            onChange={(e) => setStock(e.target.value)}
+            style={{ flex: 1, minWidth: 120 }}
+          />
+          <button className="btn btn-primary" onClick={handleSave} disabled={!price || patchWare.isPending}>
+            Save
+          </button>
+        </div>
+      )}
+    </div>
+  );
+}
+
+// The DM's list of what one seller has for sale — an NPC, or an encounter
+// itself — with a form to put something from the campaign pools up for sale.
+export function WaresEditor({
+  campaignId,
+  seller,
+  wares,
+  weapons,
+  items,
+  onError,
+}: {
+  campaignId: string;
+  seller: { npcId: string } | { encounterId: string };
+  wares: SaleOffer[];
+  weapons: Weapon[];
+  items: Item[];
+  onError: (err: unknown) => void;
+}) {
+  const createWare = useCreateWare(campaignId);
+
+  const [kind, setKind] = useState<'item' | 'weapon'>('item');
+  const [poolId, setPoolId] = useState('');
+  const [level, setLevel] = useState('');
+  const [price, setPrice] = useState('');
+  const [currency, setCurrency] = useState<Currency>('GOLD');
+  const [stock, setStock] = useState('');
+
+  const pool: (Weapon | Item)[] = kind === 'weapon' ? weapons : items;
+  const picked = pool.find((entry) => entry.id === poolId);
+
+  function handleAdd() {
+    const amount = Math.floor(Number(price));
+    if (!picked || !(amount > 0)) return;
+    createWare.mutate(
+      {
+        ...seller,
+        ...(kind === 'weapon' ? { weaponId: picked.id } : { itemId: picked.id }),
+        price: amount,
+        currency,
+        level: level ? Number(level) : undefined,
+        stock: stock === '' ? null : Number(stock),
+      },
+      {
+        onError,
+        onSuccess: () => {
+          setPoolId('');
+          setLevel('');
+          setPrice('');
+          setStock('');
+        },
+      }
+    );
+  }
+
+  return (
+    <div>
+      {wares.length === 0 && (
+        <p className="combatant-sub" style={{ marginTop: 0 }}>
+          Nothing for sale yet.
+        </p>
+      )}
+      {wares.map((ware) => (
+        <WareRow key={ware.id} campaignId={campaignId} ware={ware} onError={onError} />
+      ))}
+      <div className="flex-row flex-wrap gap-sm mt-sm">
+        <select
+          aria-label="What kind of thing to sell"
+          value={kind}
+          onChange={(e) => {
+            setKind(e.target.value as typeof kind);
+            setPoolId('');
+            setLevel('');
+          }}
+        >
+          <option value="item">Item</option>
+          <option value="weapon">Weapon</option>
+        </select>
+        <select
+          aria-label={kind === 'weapon' ? 'Weapon to sell' : 'Item to sell'}
+          value={poolId}
+          onChange={(e) => {
+            setPoolId(e.target.value);
+            setLevel('');
+          }}
+          style={{ flex: 1, minWidth: 110 }}
+        >
+          <option value="">{pool.length ? 'Choose…' : 'The pool is empty'}</option>
+          {pool.map((entry) => (
+            <option key={entry.id} value={entry.id}>
+              {entry.name}
+            </option>
+          ))}
+        </select>
+        {picked && (
+          <select aria-label="Level" value={level || picked.minLevel} onChange={(e) => setLevel(e.target.value)}>
+            {Array.from({ length: MAX_GEAR_LEVEL - picked.minLevel + 1 }, (_, i) => picked.minLevel + i).map((l) => (
+              <option key={l} value={l}>
+                Lv {l}
+                {picked.damageDice ? ` · ${scaledDamageDice(picked.damageDice, l, picked.damageScaling, picked.minLevel)}` : ''}
+              </option>
+            ))}
+          </select>
+        )}
+      </div>
+      <div className="flex-row flex-wrap gap-sm mt-sm">
+        <NumberInput min={1} max={1000000} placeholder="Price" aria-label="Price for one" value={price} onChange={(e) => setPrice(e.target.value)} style={{ width: 90 }} />
+        <select aria-label="Price is in" value={currency} onChange={(e) => setCurrency(e.target.value as Currency)}>
+          {CURRENCIES.map((c) => (
+            <option key={c} value={c}>
+              {COIN_LABELS[c]}
+            </option>
+          ))}
+        </select>
+        <NumberInput
+          min={0}
+          max={9999}
+          placeholder="Stock (empty = no limit)"
+          aria-label="How many are in stock"
+          title="How many can be bought. Leave empty for no limit."
+          value={stock}
+          onChange={(e) => setStock(e.target.value)}
+          style={{ flex: 1, minWidth: 120 }}
+        />
+        <button className="btn btn-primary" onClick={handleAdd} disabled={!picked || !price || createWare.isPending}>
+          Put up for sale
+        </button>
+      </div>
+    </div>
+  );
+}

frontend/src/index.css

@@ -1,4 +1,6 @@
 :root {
+  /* Dark throughout, so the browser draws its own controls dark too. */
+  color-scheme: dark;
   --bg: #131009;
   --bg-elevated: #1b160e;
   --bg-card: #221b12;
@@ -347,10 +349,8 @@ textarea {
   color: var(--text-muted);
 }
 
-input[type='text'],
-input[type='email'],
-input[type='password'],
-input[type='number'],
+/* Every text-like field, including an <input> with no type given. */
+input:not([type='checkbox']):not([type='radio']):not([type='range']):not([type='file']),
 select,
 textarea {
   background: var(--bg-inset);
@@ -631,10 +631,9 @@ input[type='radio'] {
   color: var(--accent-strong);
   outline: none;
 }
+/* Placed by InfoTip.tsx against the viewport, so no scrolling container can clip it. */
 .info-tip-bubble {
-  position: absolute;
-  bottom: calc(100% + 8px);
-  left: 50%;
+  position: fixed;
   transform: translateX(-50%);
   width: max-content;
   max-width: 260px;
@@ -648,7 +647,7 @@ input[type='radio'] {
   letter-spacing: normal;
   color: var(--text);
   box-shadow: var(--shadow-deep);
-  z-index: 100;
+  z-index: 200;
   pointer-events: none;
 }
 
@@ -806,6 +805,57 @@ table.data-table tbody tr:hover {
 .combatant.is-down {
   opacity: 0.6;
 }
+/* The marked target stands out even when it is down or not on turn. */
+.combatant.is-targeted {
+  opacity: 1;
+  border-color: var(--danger-strong);
+  box-shadow: 0 0 0 1px var(--danger-strong), 0 0 22px rgba(216, 84, 84, 0.3), var(--shadow-deep);
+}
+.target-marker {
+  color: var(--danger-strong);
+  font-family: var(--font-display);
+  font-size: 0.75rem;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+}
+.btn-target {
+  padding: 0.15rem 0.6rem;
+  font-size: 0.8rem;
+}
+.btn-target.is-on {
+  border-color: var(--danger-strong);
+  color: var(--danger-strong);
+  background: var(--danger-soft);
+}
+
+/* What players see of the dead: names, and a way to try to bring them back. */
+.fallen-bar {
+  border-color: var(--danger);
+}
+
+/* The DM's attack bar stays in reach while scrolling the initiative order. */
+.attack-bar {
+  position: sticky;
+  top: 4.5rem;
+  z-index: 20;
+  border-color: var(--danger-strong);
+}
+.attack-target {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  justify-content: space-between;
+  gap: 0.5rem;
+  margin-top: 0.5rem;
+}
+.attack-target-name {
+  font-family: var(--font-display);
+}
+.attack-bar-title {
+  font-family: var(--font-display);
+  font-size: 1.1rem;
+  color: var(--text);
+}
 .combatant-name {
   font-family: var(--font-display);
   font-size: 1.1rem;
@@ -870,6 +920,55 @@ table.data-table tbody tr:hover {
   line-height: 1;
 }
 
+/* At 0 HP: the death-save tallies and what can be done about them. */
+.death-saves {
+  margin-top: 0.6rem;
+  padding: 0.6rem 0.75rem;
+  border: 1px solid var(--danger);
+  border-radius: 6px;
+  background: var(--danger-soft);
+}
+.death-saves.is-stable {
+  border-color: var(--border);
+  background: var(--bg-inset);
+}
+.death-tally {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.4rem;
+  font-size: 0.75rem;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-muted);
+}
+.death-pips {
+  display: inline-flex;
+  gap: 0.25rem;
+}
+.death-pip {
+  width: 0.9rem;
+  height: 0.9rem;
+  padding: 0;
+  border-radius: 50%;
+  border: 2px solid var(--text-dim);
+  background: transparent;
+}
+button.death-pip {
+  cursor: pointer;
+}
+.death-pip.is-success {
+  border-color: var(--success-strong);
+}
+.death-pip.is-failure {
+  border-color: var(--danger-strong);
+}
+.death-pip.is-success.is-filled {
+  background: var(--success-strong);
+}
+.death-pip.is-failure.is-filled {
+  background: var(--danger-strong);
+}
+
 .combatant-details {
   margin-top: 0.75rem;
   padding-top: 0.75rem;
@@ -1191,3 +1290,418 @@ table.data-table tbody tr:hover {
   margin: 0;
   white-space: pre-wrap;
 }
+
+/* ---------------------------------------------------------------------- */
+/* Navigation: links along the top bar on a wide screen, a bar along the   */
+/* bottom on a phone; and a row of links to the sections of a long page    */
+/* ---------------------------------------------------------------------- */
+
+.topbar-links {
+  display: flex;
+  align-items: center;
+  gap: 0.25rem;
+}
+.topbar-link {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.35rem;
+  padding: 0.35rem 0.7rem;
+  border-radius: 6px;
+  border: 1px solid transparent;
+  color: var(--text-muted);
+  font-family: var(--font-display);
+  font-size: 0.8rem;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+}
+.topbar-link:hover {
+  text-decoration: none;
+  color: var(--accent-strong);
+  border-color: var(--border);
+}
+.topbar-link.is-active {
+  color: var(--accent-strong);
+  border-color: var(--accent);
+  background: var(--accent-soft);
+}
+.topbar-name {
+  max-width: 14ch;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.bottom-nav {
+  display: none;
+}
+
+.jump-nav {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.4rem;
+  margin-bottom: 1.25rem;
+}
+.jump-link {
+  font-family: var(--font-display);
+  font-size: 0.75rem;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  padding: 0.4rem 0.75rem;
+  border-radius: 999px;
+  border: 1px solid var(--border);
+  background: var(--bg-inset);
+  color: var(--text-muted);
+  cursor: pointer;
+}
+.jump-link:hover {
+  border-color: var(--accent);
+  color: var(--accent-strong);
+}
+/* A section jumped to stops below the sticky top bar, not under it. */
+[data-jump] {
+  scroll-margin-top: 4.5rem;
+}
+
+/* A table cell that holds a sentence rather than a figure may wrap. */
+table.data-table td.cell-title,
+table.data-table td.cell-wide {
+  white-space: normal;
+  min-width: 12rem;
+}
+
+/* ---------------------------------------------------------------------- */
+/* Small screens. Nothing may be wider than the screen: rows of controls   */
+/* wrap, fields shrink to fit, tables become stacked cards, and the main   */
+/* destinations move to a bar along the bottom.                            */
+/* ---------------------------------------------------------------------- */
+
+html {
+  -webkit-text-size-adjust: 100%;
+  text-size-adjust: 100%;
+}
+body,
+#root,
+.app-shell {
+  min-height: 100dvh;
+}
+/* A field never forces its row wider than the space there is. */
+input,
+select,
+textarea {
+  max-width: 100%;
+  min-width: 0;
+}
+
+@media (max-width: 900px) {
+  :root {
+    --bottom-nav-height: calc(3.6rem + env(safe-area-inset-bottom, 0px));
+    --dice-slot: 4.2rem;
+  }
+
+  body {
+    overflow-wrap: break-word;
+  }
+
+  .page {
+    padding: 1rem 0.85rem calc(var(--bottom-nav-height) + 1.5rem);
+  }
+  .topbar {
+    padding: 0.5rem 0.85rem;
+    gap: 0.5rem;
+  }
+  .topbar-brand {
+    font-size: 1rem;
+    min-width: 0;
+    overflow: hidden;
+    text-overflow: ellipsis;
+  }
+  .topbar-links,
+  .topbar-name {
+    display: none;
+  }
+  .topbar-nav {
+    flex-wrap: nowrap;
+  }
+
+  .bottom-nav {
+    position: fixed;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    z-index: 70;
+    display: flex;
+    height: var(--bottom-nav-height);
+    padding-bottom: env(safe-area-inset-bottom, 0px);
+    background: linear-gradient(180deg, #1e1810 0%, #120e08 100%);
+    border-top: 1px solid var(--border);
+    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.45);
+  }
+  .bottom-nav-link {
+    flex: 1 1 0;
+    min-width: 0;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 0.1rem;
+    color: var(--text-muted);
+    font-family: var(--font-display);
+    font-size: 0.68rem;
+    text-transform: uppercase;
+    letter-spacing: 0.04em;
+    border-top: 2px solid transparent;
+  }
+  .bottom-nav-link:hover {
+    text-decoration: none;
+  }
+  .bottom-nav-link .nav-icon {
+    font-size: 1.25rem;
+    line-height: 1.2;
+  }
+  .bottom-nav-link.is-active {
+    color: var(--accent-strong);
+    border-top-color: var(--accent-strong);
+    background: var(--accent-soft);
+  }
+
+  /* Nothing floats over the page on a phone. The dice roller takes the last
+     place in the bottom bar, and quick stats a place in the top bar. */
+  .bottom-nav {
+    padding-right: var(--dice-slot);
+  }
+  .fab-dice {
+    left: auto;
+    right: 0;
+    bottom: 0;
+    z-index: 71;
+    width: var(--dice-slot);
+    height: var(--bottom-nav-height);
+    padding: 0 0 env(safe-area-inset-bottom, 0px);
+    flex-direction: column;
+    gap: 0.1rem;
+    border: none;
+    border-top: 2px solid transparent;
+    border-radius: 0;
+    background: transparent;
+    box-shadow: none;
+    font-size: 1.25rem;
+    line-height: 1.2;
+    color: var(--text-muted);
+  }
+  .fab-dice::after {
+    content: 'Dice';
+    font-family: var(--font-display);
+    font-size: 0.68rem;
+    text-transform: uppercase;
+    letter-spacing: 0.04em;
+  }
+  .fab-dice:hover {
+    transform: none;
+  }
+  .dice-panel {
+    left: 0.85rem;
+    bottom: calc(var(--bottom-nav-height) + 0.6rem);
+    width: calc(100vw - 1.7rem);
+    max-height: calc(100dvh - var(--bottom-nav-height) - 5rem);
+  }
+  .fab-quickstats {
+    top: 0.3rem;
+    bottom: auto;
+    right: 6.4rem;
+    z-index: 31;
+    width: 40px;
+    height: 40px;
+    font-size: 1.15rem;
+    box-shadow: none;
+  }
+  /* The brand makes room for it. */
+  .app-shell:has(.fab-quickstats) .topbar-brand {
+    max-width: calc(100vw - 11rem);
+  }
+  .drawer {
+    width: 100vw;
+    padding: 1rem 0.85rem calc(var(--bottom-nav-height) + 1rem);
+    z-index: 95;
+  }
+  .drawer-backdrop {
+    z-index: 94;
+  }
+
+  h1 {
+    font-size: 1.5rem;
+  }
+  .card {
+    padding: 0.9rem 0.85rem;
+  }
+  .card-title {
+    flex-wrap: wrap;
+  }
+  .page-header {
+    margin-bottom: 1rem;
+  }
+
+  /* Rows of controls wrap instead of running off the side, and what is in
+     them may shrink: an inline min-width never beats the screen. */
+  .flex-row,
+  .flex-between,
+  .detail-row {
+    flex-wrap: wrap;
+  }
+  .flex-row > *,
+  .flex-between > * {
+    max-width: 100%;
+  }
+  .flex-row > input,
+  .flex-row > select,
+  .flex-row > textarea,
+  .flex-row > a,
+  .flex-between > a {
+    min-width: min(100%, 8rem) !important;
+  }
+  .btn {
+    white-space: normal;
+    padding: 0.6rem 0.9rem;
+  }
+  .grid-cols-2 {
+    grid-template-columns: minmax(0, 1fr);
+  }
+  .grid-cols-3 {
+    grid-template-columns: repeat(auto-fit, minmax(min(100%, 130px), 1fr));
+  }
+  .choice-grid {
+    grid-template-columns: 1fr;
+  }
+  .btn-roll {
+    font-size: 1.1rem;
+    padding: 1.1rem 1.25rem;
+    max-width: 100%;
+  }
+  .step-footer > * {
+    flex: 1 1 auto;
+  }
+
+  /* Things to tap are big enough to hit with a thumb. */
+  input[type='checkbox'],
+  input[type='radio'] {
+    width: 22px;
+    height: 22px;
+    flex: none;
+  }
+  .death-pip {
+    width: 1.5rem;
+    height: 1.5rem;
+  }
+  .btn-target {
+    padding: 0.4rem 0.75rem;
+  }
+  .condition-chip {
+    padding: 0.3rem 0.6rem;
+  }
+  .condition-chip button {
+    padding: 0.15rem 0.35rem;
+    font-size: 1rem;
+  }
+  .info-tip-trigger {
+    font-size: 1.05em;
+    padding: 0.2rem;
+  }
+  .pick-chip {
+    padding: 0.5rem 0.9rem;
+  }
+  .jump-link {
+    padding: 0.5rem 0.8rem;
+  }
+  .attack-bar {
+    top: 3.4rem;
+    max-height: 55dvh;
+    overflow-y: auto;
+  }
+  [data-jump] {
+    scroll-margin-top: 3.8rem;
+  }
+
+  /* Tables: every row becomes a card. The first cell is its heading; the
+     rest carry their column's name from data-label. */
+  .table-wrap {
+    overflow: visible;
+    border: none;
+  }
+  table.data-table,
+  table.data-table tbody {
+    display: block;
+  }
+  table.data-table thead {
+    display: none;
+  }
+  table.data-table tbody tr {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.35rem 0.9rem;
+    padding: 0.7rem 0.75rem;
+    margin-bottom: 0.6rem;
+    background: var(--bg-inset);
+    border: 1px solid var(--border-soft);
+    border-radius: var(--radius);
+  }
+  table.data-table tbody tr:last-child {
+    border-bottom: 1px solid var(--border-soft);
+    margin-bottom: 0;
+  }
+  table.data-table tbody tr:hover {
+    background: var(--bg-inset);
+  }
+  table.data-table td {
+    display: flex;
+    align-items: center;
+    gap: 0.4rem;
+    padding: 0;
+    white-space: normal;
+    min-width: 0;
+  }
+  table.data-table td:empty {
+    display: none;
+  }
+  table.data-table td.cell-title,
+  table.data-table td.cell-wide {
+    display: block;
+    flex: 1 1 100%;
+    min-width: 0;
+  }
+  table.data-table td.cell-title {
+    font-size: 1.05rem;
+  }
+  table.data-table td[data-label]::before {
+    content: attr(data-label);
+    font-size: 0.65rem;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    color: var(--text-dim);
+    flex: none;
+  }
+  table.data-table td.cell-actions {
+    margin-left: auto;
+  }
+}
+
+/* The narrowest phones: five places in the bottom bar still fit. */
+@media (max-width: 380px) {
+  :root {
+    --dice-slot: 3.4rem;
+  }
+  .bottom-nav-link,
+  .fab-dice::after {
+    font-size: 0.58rem;
+    letter-spacing: 0;
+  }
+}
+
+/* Between a phone and a full desktop the top bar drops the name to stay on one line. */
+@media (max-width: 1080px) {
+  .topbar-name {
+    display: none;
+  }
+  .topbar-nav {
+    flex-wrap: nowrap;
+  }
+}

frontend/src/lib/format.ts

@@ -1,3 +1,5 @@
+import type { Coin, Currency } from '../api/types';
+
 export const SPECIES_LABELS: Record<string, string> = {
   HUMAN: 'Human',
   HALF_ELF: 'Half-Elf',
@@ -70,6 +72,38 @@ export function hpBarClass(current: number, max: number): string {
   return 'hp-bar-fill';
 }
 
+// Coins. Silver is worth 0.1 gold and copper 0.01 gold.
+export const COINS: Coin[] = ['GOLD', 'SILVER', 'COPPER'];
+// Everything a purse can hold: the coins, plus cash ($) for crossover worlds.
+// Cash has no worth in coins, so it is never exchanged or used to make change.
+export const CURRENCIES: Currency[] = [...COINS, 'CASH'];
+export const COIN_LABELS: Record<Currency, string> = { GOLD: 'Gold', SILVER: 'Silver', COPPER: 'Copper', CASH: 'Cash ($)' };
+export const COIN_FIELD: Record<Currency, 'gold' | 'silver' | 'copper' | 'cash'> = { GOLD: 'gold', SILVER: 'silver', COPPER: 'copper', CASH: 'cash' };
+// What one coin is worth, counted in copper.
+export const COIN_VALUE: Record<Coin, number> = { GOLD: 100, SILVER: 10, COPPER: 1 };
+const COIN_SHORT: Record<Coin, string> = { GOLD: 'gp', SILVER: 'sp', COPPER: 'cp' };
+
+// "12 gp", "5 sp", "$40". With `long`, coins are spelled out: "12 gold".
+export function formatMoney(amount: number, currency: Currency, long = false): string {
+  if (currency === 'CASH') return `$${amount}`;
+  return `${amount} ${long ? COIN_LABELS[currency].toLowerCase() : COIN_SHORT[currency]}`;
+}
+
+type Purse = { gold: number | null; silver: number | null; copper: number | null; cash: number | null };
+
+// "12 gp · 5 sp · 3 cp · $40". Gold always shows; the rest only when held.
+export function formatPurse(purse: Purse): string {
+  return CURRENCIES.filter((c) => c === 'GOLD' || (purse[COIN_FIELD[c]] ?? 0) > 0)
+    .map((c) => formatMoney(purse[COIN_FIELD[c]] ?? 0, c))
+    .join(' · ');
+}
+
+// The purse's coins as one figure in gold, e.g. 12.65. Cash is not counted.
+export function purseWorthInGold(purse: Purse): number {
+  const copper = COINS.reduce((sum, c) => sum + (purse[COIN_FIELD[c]] ?? 0) * COIN_VALUE[c], 0);
+  return copper / COIN_VALUE.GOLD;
+}
+
 export function extractErrorMessage(err: unknown): string {
   const anyErr = err as { response?: { data?: { error?: unknown } } };
   const apiError = anyErr?.response?.data?.error;

frontend/src/lib/lastCampaign.ts

@@ -0,0 +1,34 @@
+import { useEffect, useSyncExternalStore } from 'react';
+
+// The campaign the user was last in, so the navigation can always offer a way
+// back to it — from a character sheet or an encounter, whose addresses don't
+// say which campaign they belong to. Kept per browser.
+const KEY = 'dnd_last_campaign';
+const listeners = new Set<() => void>();
+
+function read(): string | null {
+  return localStorage.getItem(KEY);
+}
+
+function subscribe(listener: () => void) {
+  listeners.add(listener);
+  return () => listeners.delete(listener);
+}
+
+export function forgetCampaign() {
+  localStorage.removeItem(KEY);
+  listeners.forEach((listener) => listener());
+}
+
+export function useLastCampaignId(): string | null {
+  return useSyncExternalStore(subscribe, read);
+}
+
+// Call from any page that knows which campaign it is showing.
+export function useRememberCampaign(campaignId: string | null | undefined) {
+  useEffect(() => {
+    if (!campaignId || read() === campaignId) return;
+    localStorage.setItem(KEY, campaignId);
+    listeners.forEach((listener) => listener());
+  }, [campaignId]);
+}

frontend/src/lib/wares.ts

@@ -0,0 +1,14 @@
+import { scaledDamageDice } from './previewCalc';
+import type { SaleOffer } from '../api/types';
+
+// "🗡 Longsword · Lv 2 · 1d10": what a ware is, for anyone looking at it.
+export function wareName(ware: SaleOffer): string {
+  const entry = ware.weapon ?? ware.item;
+  if (!entry) return 'Removed from the pool';
+  const dice = entry.damageDice ? ` · ${scaledDamageDice(entry.damageDice, ware.level, entry.damageScaling, entry.minLevel)}` : '';
+  return `${ware.weapon ? '🗡' : '🎒'} ${entry.name} · Lv ${ware.level}${dice}`;
+}
+
+export function stockLabel(ware: SaleOffer): string {
+  return ware.stock === null ? 'always in stock' : ware.stock === 0 ? 'sold out' : `${ware.stock} left`;
+}

frontend/src/pages/CampaignHomePage.tsx

@@ -1,4 +1,4 @@
-import { useState, type FormEvent } from 'react';
+import { useState, type CSSProperties, type FormEvent, type ReactNode } from 'react';
 import { Link, useNavigate, useParams } from 'react-router-dom';
 import {
   useCampaign,
@@ -12,6 +12,7 @@ import {
   useDeleteEncounter,
   useCampaignMonsters,
   useCreateMonster,
+  useUpdateMonster,
   useDeleteMonster,
   useCampaignWeapons,
   useCreateWeapon,
@@ -41,11 +42,14 @@ import { useAuth } from '../auth/AuthContext';
 import { useCampaignSocket } from '../hooks/useCampaignSocket';
 import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
+import { JumpNav } from '../components/JumpNav';
+import { LifeBadge } from '../components/DeathSaves';
 import { usePagination, Pagination } from '../components/Paginated';
-import { SPELL_DAMAGE_GROUPS, SPELL_DAMAGE_SPECIALS, extractErrorMessage, spellLevelLabel, spellRequirementLabel } from '../lib/format';
+import { WaresEditor } from '../components/Wares';
+import { SPELL_DAMAGE_GROUPS, SPELL_DAMAGE_SPECIALS, extractErrorMessage, fmtMod, formatMoney, spellLevelLabel, spellRequirementLabel } from '../lib/format';
 import { speciesIcon } from '../lib/speciesIcons';
-import { DAMAGE_SCALING_LABELS, MAX_GEAR_LEVEL } from '../lib/previewCalc';
-import type { CharacterSummary, Encounter, EncounterMode, LibraryMonster, LibrarySpell, LibraryWeapon, NpcDisposition } from '../api/types';
+import { ABILITY_ORDER, DAMAGE_SCALING_LABELS, MAX_GEAR_LEVEL } from '../lib/previewCalc';
+import type { CharacterSummary, Encounter, EncounterMode, Item, LibraryMonster, LibrarySpell, LibraryWeapon, Monster, Npc, NpcDisposition, Weapon } from '../api/types';
 
 // How the encounter list can be ordered. "custom" is the campaign's own order,
 // which the DM arranges; the rest only change what this browser shows.
@@ -102,7 +106,7 @@ function CharacterRow({ character, isDM, onDelete }: { character: CharacterSumma
       <div className="flex-row">
         {!inProgress && (
           <div style={{ textAlign: 'right', fontSize: '0.85rem', color: 'var(--text-muted)' }}>
-            HP {character.currentHp}/{character.maxHp} · AC {character.armorClass}
+            <LifeBadge deathSaves={character.deathSaves} /> HP {character.currentHp}/{character.maxHp} · AC {character.armorClass}
           </div>
         )}
         <Link to={inProgress ? `/characters/${character.id}/build` : `/characters/${character.id}`} className="btn">
@@ -131,7 +135,7 @@ function PoolRowControls({
 }) {
   return (
     <>
-      <td>
+      <td data-label="Starting option">
         <input
           type="checkbox"
           aria-label={`${entry.name} is a starting option`}
@@ -139,7 +143,7 @@ function PoolRowControls({
           onChange={(e) => onToggleStarting(e.target.checked)}
         />
       </td>
-      <td>
+      <td className="cell-actions">
         <button
           className="btn btn-ghost"
           aria-label={`Remove ${entry.name}`}
@@ -235,6 +239,214 @@ function SpellDamageSelect({
   );
 }
 
+type MonsterInput = Omit<Monster, 'id' | 'campaignId'>;
+type AbilityScores = Pick<Monster, 'strScore' | 'dexScore' | 'conScore' | 'intScore' | 'wisScore' | 'chaScore'>;
+const scoreField = (ability: string) => `${ability.toLowerCase()}Score` as keyof AbilityScores;
+
+// "STR 8 · DEX 14 · …", in stat-block order.
+function abilityLine(scores: AbilityScores): string {
+  return ABILITY_ORDER.map((a) => `${a} ${scores[scoreField(a)]}`).join(' · ');
+}
+
+// The whole stat block, field for field as a printed one gives it. Adds a
+// monster, or edits one when `monster` is passed (its values fill the form).
+function MonsterForm({
+  monster,
+  saving,
+  onSave,
+  onCancel,
+}: {
+  monster?: Monster;
+  saving: boolean;
+  // Rejects if the save failed, so the form keeps what was typed.
+  onSave: (data: MonsterInput) => Promise<void>;
+  onCancel?: () => void;
+}) {
+  const field = (name: string, label: string, input: ReactNode, style?: CSSProperties) => (
+    <div className="field" style={{ marginBottom: 0, ...style }}>
+      <label htmlFor={`monster-${name}`}>{label}</label>
+      {input}
+    </div>
+  );
+  const number = (name: keyof MonsterInput, label: string, min: number, max: number, fallback?: number) =>
+    field(
+      name,
+      label,
+      <NumberInput
+        id={`monster-${name}`}
+        name={name}
+        min={min}
+        max={max}
+        defaultValue={(monster?.[name] as number | undefined) ?? fallback}
+        keepValue={fallback !== undefined}
+        required
+      />
+    );
+
+  return (
+    <form
+      onSubmit={async (e) => {
+        e.preventDefault();
+        const form = e.target as HTMLFormElement;
+        const fd = new FormData(form);
+        const text = (key: string) => String(fd.get(key) || '').trim() || null;
+        const num = (key: string) => Number(fd.get(key));
+        try {
+          await onSave({
+            name: String(fd.get('name')).trim(),
+            challengeRating: text('challengeRating'),
+            ac: num('ac'),
+            maxHp: num('maxHp'),
+            speed: num('speed'),
+            attackBonus: num('attackBonus'),
+            damageDice: text('damageDice'),
+            strScore: num('strScore'),
+            dexScore: num('dexScore'),
+            conScore: num('conScore'),
+            intScore: num('intScore'),
+            wisScore: num('wisScore'),
+            chaScore: num('chaScore'),
+            specialTrait: text('specialTrait'),
+            notes: text('notes'),
+          });
+          if (!monster) form.reset();
+        } catch {
+          // The page shows the error; what was typed stays.
+        }
+      }}
+    >
+      <div className="grid grid-cols-3">
+        {field('name', 'Name', <input id="monster-name" name="name" defaultValue={monster?.name} required maxLength={80} />)}
+        {field(
+          'challengeRating',
+          'CR (Challenge Rating)',
+          <input id="monster-challengeRating" name="challengeRating" defaultValue={monster?.challengeRating ?? ''} placeholder="e.g. 1/4 or 3" maxLength={10} />
+        )}
+        {number('ac', 'AC (Armor Class)', 0, 50)}
+        {number('maxHp', 'HP (Hit Points)', 1, 100000)}
+        {number('speed', 'Speed (feet)', 0, 1000, 30)}
+        {number('attackBonus', 'Attack bonus', -20, 50, 0)}
+        {field(
+          'damageDice',
+          'Damage',
+          <input id="monster-damageDice" name="damageDice" defaultValue={monster?.damageDice ?? ''} placeholder="e.g. 1d6+2 necrotic" maxLength={60} />
+        )}
+      </div>
+      <div className="grid mt-sm" style={{ gridTemplateColumns: 'repeat(auto-fit, minmax(80px, 1fr))' }}>
+        {ABILITY_ORDER.map((a) => number(scoreField(a), a, 1, 30, 10))}
+      </div>
+      {field(
+        'specialTrait',
+        'Special trait',
+        <input
+          id="monster-specialTrait"
+          name="specialTrait"
+          defaultValue={monster?.specialTrait ?? ''}
+          placeholder="The one thing that makes it different"
+          maxLength={500}
+        />,
+        { marginTop: '0.5rem' }
+      )}
+      {field(
+        'notes',
+        'Notes',
+        <textarea
+          id="monster-notes"
+          name="notes"
+          rows={3}
+          className="textarea-block"
+          defaultValue={monster?.notes ?? ''}
+          placeholder="Everything else: other speeds (fly 30, swim 40), extra attacks, spells, tactics, resistances, senses, what it drops"
+          maxLength={2000}
+        />,
+        { marginTop: '0.5rem' }
+      )}
+      <div className="flex-row mt-sm">
+        <button type="submit" className="btn btn-primary" disabled={saving}>
+          {monster ? 'Save Changes' : 'Add Monster'}
+        </button>
+        {onCancel && (
+          <button type="button" className="btn btn-ghost" onClick={onCancel}>
+            Cancel
+          </button>
+        )}
+      </div>
+    </form>
+  );
+}
+
+// "1 gp = $5": the rate an NPC changes gold and cash at, or null if they don't.
+function rateLabel(npc: Pick<Npc, 'exchangeGold' | 'exchangeCash'>): string | null {
+  if (!npc.exchangeGold || !npc.exchangeCash) return null;
+  return `${formatMoney(npc.exchangeGold, 'GOLD')} = ${formatMoney(npc.exchangeCash, 'CASH')}`;
+}
+
+// What an NPC trades: the rate they change gold and cash at, and their wares.
+// Players meet both on the encounter page, in a quest the NPC is part of.
+function NpcTrade({
+  campaignId,
+  npc,
+  weapons,
+  items,
+  onError,
+}: {
+  campaignId: string;
+  npc: Npc;
+  weapons: Weapon[];
+  items: Item[];
+  onError: (err: unknown) => void;
+}) {
+  const patchNpc = usePatchPoolEntry(campaignId, 'npcs');
+  const [gold, setGold] = useState(npc.exchangeGold ? String(npc.exchangeGold) : '');
+  const [cash, setCash] = useState(npc.exchangeCash ? String(npc.exchangeCash) : '');
+  const changesMoney = Boolean(rateLabel(npc));
+
+  return (
+    <div className="card mt-sm" style={{ background: 'var(--bg-inset)' }}>
+      <div className="section-label">Changes money</div>
+      <p className="combatant-sub" style={{ marginTop: 0 }}>
+        Set a rate and the party can change gold into cash, or cash into gold, with {npc.name}. Silver and copper are not
+        taken. Leave it empty for someone who does not change money.
+      </p>
+      <div className="flex-row flex-wrap gap-sm">
+        <NumberInput min={1} max={1000000} aria-label="Gold side of the rate" placeholder="Gold" value={gold} onChange={(e) => setGold(e.target.value)} style={{ width: 90 }} />
+        <span>gold =</span>
+        <span>$</span>
+        <NumberInput min={1} max={1000000} aria-label="Cash side of the rate" placeholder="Cash" value={cash} onChange={(e) => setCash(e.target.value)} style={{ width: 90 }} />
+        <button
+          className="btn"
+          disabled={!gold || !cash || patchNpc.isPending}
+          onClick={() => patchNpc.mutate({ id: npc.id, exchangeGold: Number(gold), exchangeCash: Number(cash) }, { onError })}
+        >
+          Save rate
+        </button>
+        {changesMoney && (
+          <button
+            className="btn btn-ghost"
+            disabled={patchNpc.isPending}
+            onClick={() =>
+              patchNpc.mutate(
+                { id: npc.id, exchangeGold: null, exchangeCash: null },
+                {
+                  onError,
+                  onSuccess: () => {
+                    setGold('');
+                    setCash('');
+                  },
+                }
+              )
+            }
+          >
+            Stop changing money
+          </button>
+        )}
+      </div>
+      <div className="section-label mt-md">For sale</div>
+      <WaresEditor campaignId={campaignId} seller={{ npcId: npc.id }} wares={npc.wares ?? []} weapons={weapons} items={items} onError={onError} />
+    </div>
+  );
+}
+
 function LibraryPicker<T extends { key: string; name: string }>({
   items,
   onAdd,
@@ -303,6 +515,7 @@ export function CampaignHomePage() {
   const setEncounterArchived = useSetEncounterArchived(campaignId);
   const deleteEncounter = useDeleteEncounter(campaignId);
   const createMonster = useCreateMonster(campaignId);
+  const updateMonster = useUpdateMonster(campaignId);
   const deleteMonster = useDeleteMonster(campaignId);
   const createWeapon = useCreateWeapon(campaignId);
   const createSpell = useCreateSpell(campaignId);
@@ -332,6 +545,7 @@ export function CampaignHomePage() {
   const [encounterSort, setEncounterSort] = useState<EncounterSort>(storedEncounterSort);
   const [showArchivedEncounters, setShowArchivedEncounters] = useState(false);
   const [showNpcForm, setShowNpcForm] = useState(false);
+  const [tradeNpcId, setTradeNpcId] = useState<string | null>(null);
   const [noteBody, setNoteBody] = useState('');
   const [dmNoteBody, setDmNoteBody] = useState('');
   const [newLocationName, setNewLocationName] = useState('');
@@ -340,6 +554,7 @@ export function CampaignHomePage() {
   const [showDelete, setShowDelete] = useState(false);
   const [deleteConfirmName, setDeleteConfirmName] = useState('');
   const [showMonsterForm, setShowMonsterForm] = useState(false);
+  const [editingMonsterId, setEditingMonsterId] = useState<string | null>(null);
   const [showWeaponForm, setShowWeaponForm] = useState(false);
   const [showSpellForm, setShowSpellForm] = useState(false);
   const [showItemForm, setShowItemForm] = useState(false);
@@ -352,9 +567,12 @@ export function CampaignHomePage() {
   const itemsPage = usePagination(items, 8);
   const npcsPage = usePagination(npcs, 8);
   const monstersPage = usePagination(monsters, 8);
+  const editingMonster = monsters?.find((m) => m.id === editingMonsterId);
   const liveEncounters = encounters?.filter((e) => !e.archivedAt) || [];
   const archivedEncounters = encounters?.filter((e) => e.archivedAt) || [];
   const shownEncounters = sortEncounters(liveEncounters, encounterSort);
+  const encountersPage = usePagination(shownEncounters, 10);
+  const archivedEncountersPage = usePagination(archivedEncounters, 10);
   const sharedNotes = notes?.filter((n) => n.visibility === 'SHARED');
   const dmNotes = notes?.filter((n) => n.visibility === 'DM_ONLY');
   const sharedNotesPage = usePagination(sharedNotes, 6);
@@ -461,8 +679,10 @@ export function CampaignHomePage() {
         </div>
       </div>
 
+      <JumpNav />
+
       {isDM && (
-        <div className="card">
+        <div data-jump="Settings" className="card">
           <div className="card-title">
             <span>Campaign Settings</span>
             <button className="btn btn-ghost" onClick={() => setShowSettings((s) => !s)}>
@@ -488,6 +708,7 @@ export function CampaignHomePage() {
                   startingSpellCount: Number(fd.get('startingSpellCount')),
                   skipMotivationRoll: fd.get('skipMotivationRoll') === 'on',
                   showMonsterHp: fd.get('showMonsterHp') === 'on',
+                  areaAttackAcPenalty: Number(fd.get('areaAttackAcPenalty')),
                 });
               }}
             >
@@ -513,6 +734,19 @@ export function CampaignHomePage() {
                 <input type="checkbox" name="showMonsterHp" defaultChecked={campaign.showMonsterHp} />
                 Players see the exact hit points of monsters and NPCs in encounters (untick for a health bar only)
               </label>
+              <label className="flex-row flex-wrap gap-sm mt-sm">
+                Area attack AC penalty
+                <NumberInput
+                  name="areaAttackAcPenalty"
+                  min={0}
+                  max={10}
+                  keepValue
+                  defaultValue={campaign.areaAttackAcPenalty}
+                  style={{ width: 70 }}
+                  title="An attack on several targets is harder to land: each target's AC counts as this much higher for every target beyond the first. 0 turns the penalty off."
+                />
+                <span className="combatant-sub">added to each target's AC for every target beyond the first (0 for none)</span>
+              </label>
               <button type="submit" className="btn btn-primary mt-md" disabled={updateCampaign.isPending}>
                 Save Settings
               </button>
@@ -581,7 +815,7 @@ export function CampaignHomePage() {
       {formError && <div className="mt-md"><ErrorBanner message={formError} /></div>}
 
       {!isDM && myCharacters.length > 0 && (
-        <div className="mt-lg">
+        <div data-jump="My characters" className="mt-lg">
           <h2 style={{ fontSize: '1.1rem' }}>Your Character{myCharacters.length > 1 ? 's' : ''}</h2>
           {myCharacters.map((c) => (
             <CharacterRow key={c.id} character={c} isDM={false} onDelete={() => {}} />
@@ -589,7 +823,7 @@ export function CampaignHomePage() {
         </div>
       )}
 
-      <div className="mt-lg">
+      <div data-jump={isDM ? 'Characters' : 'Party'} className="mt-lg">
         <div className="page-header" style={{ marginBottom: '0.75rem' }}>
           <h2 style={{ fontSize: '1.1rem', margin: 0 }}>{isDM ? 'Characters' : 'Rest of the Party'}</h2>
         </div>
@@ -617,7 +851,7 @@ export function CampaignHomePage() {
         ))}
       </div>
 
-      <div className="mt-lg">
+      <div data-jump="Encounters" className="mt-lg">
         <div className="page-header" style={{ marginBottom: '0.75rem' }}>
           <h2 style={{ fontSize: '1.1rem', margin: 0 }}>Encounters</h2>
           {liveEncounters.length > 1 && (
@@ -659,13 +893,17 @@ export function CampaignHomePage() {
         )}
         {isDM && encounterSort === 'custom' && liveEncounters.length > 1 && (
           <p className="subtitle" style={{ marginTop: 0 }}>
-            This is the campaign's own order, which everyone sees by default. Use ▲ and ▼ to rearrange it.
+            This is the campaign's own order, which everyone sees by default. Use ▲ and ▼ to rearrange it; moving past the
+            top or bottom of a page carries an encounter onto the next one.
           </p>
         )}
         {encounters && liveEncounters.length === 0 && (
           <div className="empty-state">{archivedEncounters.length > 0 ? 'Every encounter is archived.' : 'No encounters yet.'}</div>
         )}
-        {shownEncounters.map((enc, index) => (
+        {encountersPage.pageItems.map((enc) => {
+          // Its place in the whole list, not on this page: that is what moving it changes.
+          const index = shownEncounters.indexOf(enc);
+          return (
           <div key={enc.id} className="card flex-between flex-wrap">
             <Link to={`/encounters/${enc.id}`} style={{ flex: 1, minWidth: 200 }}>
               <span className="badge" style={{ marginRight: 8 }}>{MODE_LABELS[enc.mode]}</span>
@@ -710,7 +948,9 @@ export function CampaignHomePage() {
               )}
             </span>
           </div>
-        ))}
+          );
+        })}
+        <Pagination page={encountersPage.page} pageCount={encountersPage.pageCount} onPrev={encountersPage.prevPage} onNext={encountersPage.nextPage} />
 
         {isDM && archivedEncounters.length > 0 && (
           <div className="mt-md">
@@ -723,7 +963,7 @@ export function CampaignHomePage() {
             {showArchivedEncounters && (
               <>
                 <p className="subtitle" style={{ marginTop: 0 }}>Players don't see these in their list.</p>
-                {archivedEncounters.map((enc) => (
+                {archivedEncountersPage.pageItems.map((enc) => (
                   <div key={enc.id} className="card flex-between flex-wrap">
                     <Link to={`/encounters/${enc.id}`} style={{ flex: 1, minWidth: 200 }}>
                       <span className="badge" style={{ marginRight: 8 }}>{MODE_LABELS[enc.mode]}</span>
@@ -750,6 +990,12 @@ export function CampaignHomePage() {
                     </span>
                   </div>
                 ))}
+                <Pagination
+                  page={archivedEncountersPage.page}
+                  pageCount={archivedEncountersPage.pageCount}
+                  onPrev={archivedEncountersPage.prevPage}
+                  onNext={archivedEncountersPage.nextPage}
+                />
               </>
             )}
           </div>
@@ -757,7 +1003,7 @@ export function CampaignHomePage() {
       </div>
 
       {!isDM && locations && locations.length > 0 && (
-        <div className="mt-lg card">
+        <div data-jump="Places" className="mt-lg card">
           <div className="card-title">Places You've Been</div>
           {locations.map((loc) => (
             <div key={loc.id} style={{ padding: '0.5rem 0', borderBottom: '1px solid var(--border-soft)' }}>
@@ -769,7 +1015,7 @@ export function CampaignHomePage() {
       )}
 
       {isDM && (
-        <div className="mt-lg card">
+        <div data-jump="NPCs" className="mt-lg card">
           <div className="card-title">
             <span>NPCs</span>
             <button className="btn btn-ghost" onClick={() => setShowNpcForm((s) => !s)}>
@@ -778,7 +1024,8 @@ export function CampaignHomePage() {
           </div>
           <p className="subtitle" style={{ marginTop: 0 }}>
             The people your party meets. Add them to an encounter to bring them into a scene. Players never see your notes or an
-            NPC's stats.
+            NPC's stats. "Trade" sets what an NPC sells and the rate they change gold and cash at; players see both when they
+            meet the NPC in a quest.
           </p>
           {showNpcForm && (
             <form
@@ -829,21 +1076,39 @@ export function CampaignHomePage() {
           <div className="mt-sm">
             {npcs?.length === 0 && <p style={{ color: 'var(--text-muted)' }}>No NPCs yet.</p>}
             {npcsPage.pageItems.map((npc) => (
-              <div key={npc.id} className="flex-between" style={{ padding: '0.5rem 0', borderBottom: '1px solid var(--border-soft)' }}>
-                <div>
-                  <strong>{npc.name}</strong>
-                  {npc.role && <span style={{ color: 'var(--text-muted)', marginLeft: 6 }}>{npc.role}</span>}
-                  <span className={`badge badge-${npc.disposition.toLowerCase()}`} style={{ marginLeft: 8 }}>{npc.disposition}</span>
-                  {npc.description && <div style={{ color: 'var(--text-muted)', fontSize: '0.9rem' }}>{npc.description}</div>}
-                  {npc.dmNotes && <div style={{ color: 'var(--text-dim)', fontSize: '0.85rem' }}>🔒 {npc.dmNotes}</div>}
+              <div key={npc.id} style={{ padding: '0.5rem 0', borderBottom: '1px solid var(--border-soft)' }}>
+                <div className="flex-between">
+                  <div>
+                    <strong>{npc.name}</strong>
+                    {npc.role && <span style={{ color: 'var(--text-muted)', marginLeft: 6 }}>{npc.role}</span>}
+                    <span className={`badge badge-${npc.disposition.toLowerCase()}`} style={{ marginLeft: 8 }}>{npc.disposition}</span>
+                    {rateLabel(npc) && <span className="badge" style={{ marginLeft: 8 }}>💱 {rateLabel(npc)}</span>}
+                    {(npc.wares?.length ?? 0) > 0 && <span className="badge" style={{ marginLeft: 8 }}>🛒 {npc.wares?.length} for sale</span>}
+                    {npc.description && <div style={{ color: 'var(--text-muted)', fontSize: '0.9rem' }}>{npc.description}</div>}
+                    {npc.dmNotes && <div style={{ color: 'var(--text-dim)', fontSize: '0.85rem' }}>🔒 {npc.dmNotes}</div>}
+                  </div>
+                  <div className="flex-row">
+                    <button className="btn btn-ghost" onClick={() => setTradeNpcId(tradeNpcId === npc.id ? null : npc.id)}>
+                      {tradeNpcId === npc.id ? 'Close' : 'Trade'}
+                    </button>
+                    <button
+                      className="btn btn-ghost"
+                      aria-label={`Remove ${npc.name}`}
+                      onClick={() => window.confirm(`Remove ${npc.name}?`) && deleteNpc.mutate(npc.id)}
+                    >
+                      ✕
+                    </button>
+                  </div>
                 </div>
-                <button
-                  className="btn btn-ghost"
-                  aria-label={`Remove ${npc.name}`}
-                  onClick={() => window.confirm(`Remove ${npc.name}?`) && deleteNpc.mutate(npc.id)}
-                >
-                  ✕
-                </button>
+                {tradeNpcId === npc.id && (
+                  <NpcTrade
+                    campaignId={campaignId}
+                    npc={npc}
+                    weapons={weapons ?? []}
+                    items={items ?? []}
+                    onError={(err) => setFormError(extractErrorMessage(err))}
+                  />
+                )}
               </div>
             ))}
           </div>
@@ -852,7 +1117,7 @@ export function CampaignHomePage() {
       )}
 
       {isDM && (
-        <div className="mt-lg card">
+        <div data-jump="Locations" className="mt-lg card">
           <div className="card-title">
             <span>Locations</span>
           </div>
@@ -896,7 +1161,7 @@ export function CampaignHomePage() {
               must be at least a weapon's or item's level to use it, and at least a spell's level to cast it.
             </p>
           </div>
-          <div className="mt-sm card">
+          <div data-jump="Weapons" className="mt-sm card">
             <div className="card-title">
               <span>Weapons Pool</span>
               <div className="flex-row gap-sm">
@@ -970,12 +1235,12 @@ export function CampaignHomePage() {
                 <tbody>
                   {weaponsPage.pageItems.map((w) => (
                     <tr key={w.id}>
-                      <td>{w.name}</td>
-                      <td>{w.damageDice} {w.damageType}</td>
-                      <td>
+                      <td className="cell-title">{w.name}</td>
+                      <td data-label="Base damage">{w.damageDice} {w.damageType}</td>
+                      <td data-label="Level">
                         <StartLevelSelect value={w.minLevel} onChange={(minLevel) => patchWeapon.mutate({ id: w.id, minLevel })} />
                       </td>
-                      <td>
+                      <td data-label="Growth">
                         <ScalingSelect value={w.damageScaling} onChange={(damageScaling) => patchWeapon.mutate({ id: w.id, damageScaling })} />
                       </td>
                       <PoolRowControls
@@ -991,7 +1256,7 @@ export function CampaignHomePage() {
             <Pagination page={weaponsPage.page} pageCount={weaponsPage.pageCount} onPrev={weaponsPage.prevPage} onNext={weaponsPage.nextPage} />
           </div>
 
-          <div className="mt-md card">
+          <div data-jump="Items" className="mt-md card">
             <div className="card-title">
               <span>Items Pool</span>
               <button className="btn btn-ghost" onClick={() => setShowItemForm((s) => !s)}>
@@ -1046,13 +1311,13 @@ export function CampaignHomePage() {
                   <tbody>
                     {itemsPage.pageItems.map((item) => (
                       <tr key={item.id}>
-                        <td>{item.name}</td>
-                        <td>{item.description}</td>
-                        <td>{item.damageDice || '—'}</td>
-                        <td>
+                        <td className="cell-title">{item.name}</td>
+                        <td className="cell-wide">{item.description}</td>
+                        <td data-label="Base dice">{item.damageDice || '—'}</td>
+                        <td data-label="Level">
                           <StartLevelSelect value={item.minLevel} onChange={(minLevel) => patchItem.mutate({ id: item.id, minLevel })} />
                         </td>
-                        <td>
+                        <td data-label="Growth">
                           {item.damageDice ? (
                             <ScalingSelect value={item.damageScaling} onChange={(damageScaling) => patchItem.mutate({ id: item.id, damageScaling })} />
                           ) : (
@@ -1073,7 +1338,7 @@ export function CampaignHomePage() {
             <Pagination page={itemsPage.page} pageCount={itemsPage.pageCount} onPrev={itemsPage.prevPage} onNext={itemsPage.nextPage} />
           </div>
 
-          <div className="mt-md card">
+          <div data-jump="Spells" className="mt-md card">
             <div className="card-title">
               <span>Spell List</span>
               <div className="flex-row gap-sm">
@@ -1114,6 +1379,7 @@ export function CampaignHomePage() {
                     description: String(fd.get('description') || '').trim() || null,
                     damageDice: String(fd.get('damageDice') || '') || null,
                     isStartingOption: fd.get('isStartingOption') === 'on',
+                    revives: fd.get('revives') === 'on',
                   });
                   (e.target as HTMLFormElement).reset();
                 }}
@@ -1134,6 +1400,10 @@ export function CampaignHomePage() {
                   <input type="checkbox" name="isStartingOption" />
                   Starting option
                 </label>
+                <label className="checkbox-row" title="A character who can cast it may revive a dead ally on their turn in a battle">
+                  <input type="checkbox" name="revives" />
+                  Revives the dead
+                </label>
                 <button type="submit" className="btn btn-primary">Add</button>
               </form>
             )}
@@ -1144,6 +1414,7 @@ export function CampaignHomePage() {
                     <th>Spell</th>
                     <th>Level</th>
                     <th>Damage</th>
+                    <th title="A character who can cast it may revive a dead ally on their turn in a battle">Revives</th>
                     <th>Starting</th>
                     <th />
                   </tr>
@@ -1151,14 +1422,22 @@ export function CampaignHomePage() {
                 <tbody>
                   {spellsPage.pageItems.map((s) => (
                     <tr key={s.id}>
-                      <td>
+                      <td className="cell-title">
                         <strong>{s.name}</strong>
                         <div style={{ color: 'var(--text-muted)', fontSize: '0.9rem' }}>{s.description || 'No description.'}</div>
                       </td>
-                      <td style={{ whiteSpace: 'nowrap' }}>{spellLevelLabel(s.level)}</td>
-                      <td>
+                      <td data-label="Level" style={{ whiteSpace: 'nowrap' }}>{spellLevelLabel(s.level)}</td>
+                      <td data-label="Damage">
                         <SpellDamageSelect spellName={s.name} value={s.damageDice} onChange={(damageDice) => patchSpell.mutate({ id: s.id, damageDice })} />
                       </td>
+                      <td data-label="Revives">
+                        <input
+                          type="checkbox"
+                          aria-label={`${s.name} revives the dead`}
+                          checked={s.revives}
+                          onChange={(e) => patchSpell.mutate({ id: s.id, revives: e.target.checked })}
+                        />
+                      </td>
                       <PoolRowControls
                         entry={s}
                         onToggleStarting={(isStartingOption) => patchSpell.mutate({ id: s.id, isStartingOption })}
@@ -1172,15 +1451,21 @@ export function CampaignHomePage() {
             <Pagination page={spellsPage.page} pageCount={spellsPage.pageCount} onPrev={spellsPage.prevPage} onNext={spellsPage.nextPage} />
           </div>
 
-          <div className="mt-md card">
+          <div data-jump="Monsters" className="mt-md card">
             <div className="card-title">
               <span>Monsters</span>
               <div className="flex-row gap-sm">
                 <button className="btn btn-ghost" onClick={() => setShowMonsterLibrary((s) => !s)}>
                   {showMonsterLibrary ? 'Close Library' : '📚 From Library'}
                 </button>
-                <button className="btn btn-ghost" onClick={() => setShowMonsterForm((s) => !s)}>
-                  {showMonsterForm ? 'Close' : '+ Add Monster'}
+                <button
+                  className="btn btn-ghost"
+                  onClick={() => {
+                    setShowMonsterForm(!(showMonsterForm || editingMonster));
+                    setEditingMonsterId(null);
+                  }}
+                >
+                  {showMonsterForm || editingMonster ? 'Close' : '+ Add Monster'}
                 </button>
               </div>
             </div>
@@ -1190,62 +1475,93 @@ export function CampaignHomePage() {
                 adding={addMonsterFromLibrary.isPending}
                 onAdd={(key) => addMonsterFromLibrary.mutate(key)}
                 placeholder="Search the monster library…"
-                renderMeta={(m) => `CR ${m.challengeRating} · AC ${m.ac} · HP ${m.maxHp} · attack +${m.attackBonus}${m.damageDice ? ` for ${m.damageDice}` : ''}`}
+                renderMeta={(m) =>
+                  `CR ${m.challengeRating ?? '—'} · AC ${m.ac} · HP ${m.maxHp} · speed ${m.speed} · attack ${fmtMod(m.attackBonus)}${m.damageDice ? ` for ${m.damageDice}` : ''} · ${abilityLine(m)}`
+                }
                 renderDetail={(m) => [m.specialTrait, m.notes].filter(Boolean).join(' — ') || null}
               />
             )}
-            {showMonsterForm && (
-              <form
-                onSubmit={async (e) => {
-                  e.preventDefault();
-                  const fd = new FormData(e.target as HTMLFormElement);
-                  await createMonster.mutateAsync({
-                    name: String(fd.get('name')),
-                    ac: Number(fd.get('ac')),
-                    maxHp: Number(fd.get('maxHp')),
-                    speed: 30,
-                    strScore: 10,
-                    dexScore: 10,
-                    conScore: 10,
-                    intScore: 10,
-                    wisScore: 10,
-                    chaScore: 10,
-                    attackBonus: Number(fd.get('attackBonus') || 0),
-                    damageDice: String(fd.get('damageDice') || '') || null,
-                    challengeRating: null,
-                    specialTrait: null,
-                    notes: null,
-                  });
-                  (e.target as HTMLFormElement).reset();
-                }}
-                className="grid grid-cols-3"
-              >
-                <input name="name" placeholder="Name" required />
-                <NumberInput name="ac" min={0} max={50} placeholder="AC" required />
-                <NumberInput name="maxHp" min={1} max={100000} placeholder="Max HP" required />
-                <NumberInput name="attackBonus" min={-20} max={50} placeholder="Attack bonus" />
-                <input name="damageDice" placeholder="Damage dice" />
-                <button type="submit" className="btn btn-primary">Add</button>
-              </form>
+            {(showMonsterForm || editingMonster) && (
+              <div className="card mt-sm" style={{ background: 'var(--bg-inset)' }}>
+                {editingMonster && <div className="section-label">Editing {editingMonster.name}</div>}
+                <MonsterForm
+                  key={editingMonster?.id ?? 'new'}
+                  monster={editingMonster}
+                  saving={createMonster.isPending || updateMonster.isPending}
+                  onCancel={editingMonster ? () => setEditingMonsterId(null) : undefined}
+                  onSave={async (stats) => {
+                    setFormError(null);
+                    try {
+                      if (editingMonster) {
+                        await updateMonster.mutateAsync({ id: editingMonster.id, ...stats });
+                        setEditingMonsterId(null);
+                      } else {
+                        await createMonster.mutateAsync(stats);
+                      }
+                    } catch (err) {
+                      setFormError(extractErrorMessage(err));
+                      throw err;
+                    }
+                  }}
+                />
+              </div>
             )}
             <div className="table-wrap mt-sm">
               <table className="data-table">
                 <thead>
                   <tr>
                     <th>Name</th>
+                    <th>CR</th>
                     <th>AC</th>
                     <th>HP</th>
+                    <th>Speed</th>
+                    <th>Attack</th>
+                    <th>Damage</th>
+                    <th />
                     <th />
                   </tr>
                 </thead>
                 <tbody>
                   {monstersPage.pageItems.map((m) => (
                     <tr key={m.id}>
-                      <td>{m.name}</td>
-                      <td>{m.ac}</td>
-                      <td>{m.maxHp}</td>
+                      <td className="cell-title">
+                        <strong>{m.name}</strong>
+                        <div className="mono" style={{ color: 'var(--text-muted)', fontSize: '0.8rem' }}>{abilityLine(m)}</div>
+                        {m.specialTrait && (
+                          <div style={{ fontSize: '0.9rem' }}>
+                            <strong>Trait:</strong> {m.specialTrait}
+                          </div>
+                        )}
+                        {m.notes && <div style={{ color: 'var(--text-muted)', fontSize: '0.9rem', whiteSpace: 'pre-wrap' }}>{m.notes}</div>}
+                      </td>
+                      <td data-label="CR">{m.challengeRating || '—'}</td>
+                      <td data-label="AC">{m.ac}</td>
+                      <td data-label="HP">{m.maxHp}</td>
+                      <td data-label="Speed">{m.speed}</td>
+                      <td data-label="Attack">{fmtMod(m.attackBonus)}</td>
+                      <td data-label="Damage">{m.damageDice || '—'}</td>
+                      <td className="cell-actions">
+                        <button
+                          className="btn btn-ghost"
+                          aria-label={`Edit ${m.name}`}
+                          onClick={() => {
+                            setEditingMonsterId(m.id);
+                            setShowMonsterForm(false);
+                          }}
+                        >
+                          Edit
+                        </button>
+                      </td>
                       <td>
-                        <button className="btn btn-ghost" onClick={() => deleteMonster.mutate(m.id)}>✕</button>
+                        <button
+                          className="btn btn-ghost"
+                          aria-label={`Remove ${m.name}`}
+                          onClick={() =>
+                            window.confirm(`Remove ${m.name}? Copies already in encounters stay, but lose their stat block.`) && deleteMonster.mutate(m.id)
+                          }
+                        >
+                          ✕
+                        </button>
                       </td>
                     </tr>
                   ))}
@@ -1257,7 +1573,7 @@ export function CampaignHomePage() {
         </>
       )}
 
-      <div className="mt-lg card">
+      <div data-jump="Notes" className="mt-lg card">
         <div className="card-title">Shared Notes</div>
         <form onSubmit={handleCreateNote} className="flex-row flex-wrap">
           <textarea

frontend/src/pages/CharacterBuilderPage.tsx

@@ -1,5 +1,6 @@
 import { useState, type ReactNode } from 'react';
 import { useNavigate, useParams } from 'react-router-dom';
+import { useRememberCampaign } from '../lib/lastCampaign';
 import { useBuildBack, useBuildChoose, useBuildFinalize, useBuildOptions, useBuildRoll, useCampaign, useCampaignItems, useCampaignSpells, useCampaignWeapons, useCharacter, usePatchDiceMode } from '../api/queries';
 import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
@@ -95,6 +96,7 @@ export function CharacterBuilderPage() {
   const { characterId = '' } = useParams();
   const navigate = useNavigate();
   const { data: character, isLoading, error } = useCharacter(characterId);
+  useRememberCampaign(character?.campaignId);
   const roll = useBuildRoll(characterId);
   const choose = useBuildChoose(characterId);
   const finalize = useBuildFinalize(characterId);

frontend/src/pages/CharacterSheetPage.tsx

@@ -17,6 +17,7 @@ import {
   useRemoveCharacterSpell,
   useGoldLedger,
   useAdjustGold,
+  useExchangeCoins,
   useCampaignCharacters,
   useGive,
   type Gift,
@@ -31,15 +32,34 @@ import { useAuth } from '../auth/AuthContext';
 import { useCampaignSocket } from '../hooks/useCampaignSocket';
 import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
+import { JumpNav } from '../components/JumpNav';
+import { useRememberCampaign } from '../lib/lastCampaign';
 import { HpBar } from '../components/HpBar';
+import { DeathSaves } from '../components/DeathSaves';
 import { QuickStatsFab } from '../components/QuickStatsDrawer';
 import { InfoTip } from '../components/InfoTip';
 import { usePagination, Pagination } from '../components/Paginated';
-import { ABILITY_LABELS, CLASS_LABELS, SKILL_LABELS, SPECIES_LABELS, fmtMod, extractErrorMessage, spellLevelLabel } from '../lib/format';
+import {
+  ABILITY_LABELS,
+  CLASS_LABELS,
+  COINS,
+  COIN_FIELD,
+  COIN_LABELS,
+  COIN_VALUE,
+  CURRENCIES,
+  SKILL_LABELS,
+  SPECIES_LABELS,
+  fmtMod,
+  extractErrorMessage,
+  formatMoney,
+  formatPurse,
+  purseWorthInGold,
+  spellLevelLabel,
+} from '../lib/format';
 import { speciesIcon } from '../lib/speciesIcons';
 import { hpMax as previewHpMax, scaledDamageDice, MAX_GEAR_LEVEL } from '../lib/previewCalc';
 import { CLASS_HIT_DIE } from '../lib/classData';
-import type { Ability, CharacterDetail } from '../api/types';
+import type { Ability, CharacterDetail, Coin, Currency } from '../api/types';
 
 // The DM's level picker for one held weapon or item, from the level the gear
 // starts at up to the maximum. Each option shows what the dice become at that
@@ -89,20 +109,26 @@ function GiveCard({ character, onError }: { character: CharacterDetail; onError:
   const others = characters?.filter((c) => c.id !== character.id && c.buildStage === 'COMPLETE') ?? [];
   if (others.length === 0) return null;
 
-  // "kind:id" identifies the thing picked; gold has no id.
+  // "kind:id" identifies the thing picked; for coins the id is which coin.
   const [kind, id] = what.split(':');
+  const coin = (kind === 'gold' ? id : 'GOLD') as Currency;
   const heldWeapon = character.weapons.find((w) => w.weaponId === id);
   const heldItem = character.inventoryItems.find((i) => i.itemId === id);
-  const gold = character.gold ?? 0;
-  const max = kind === 'gold' ? gold : kind === 'weapon' ? (heldWeapon?.quantity ?? 0) : kind === 'item' ? (heldItem?.quantity ?? 0) : 1;
+  // A gift of coins is paid from the whole purse, with change, so any coin
+  // the purse is worth at least one of can be given. Cash is only paid in cash.
+  const held = (c: Currency) => character[COIN_FIELD[c]] ?? 0;
+  const purseInCopper = COINS.reduce((sum, c) => sum + held(c) * COIN_VALUE[c], 0);
+  const affordable = (c: Currency) => (c === 'CASH' ? held(c) : Math.floor(purseInCopper / COIN_VALUE[c]));
+  const coinsHeld = CURRENCIES.filter((c) => affordable(c) > 0);
+  const max = kind === 'gold' ? affordable(coin) : kind === 'weapon' ? (heldWeapon?.quantity ?? 0) : kind === 'item' ? (heldItem?.quantity ?? 0) : 1;
   const count = Math.floor(Number(amount));
   const countOk = kind === 'spell' || (count >= 1 && count <= max);
-  const nothingToGive = gold === 0 && character.weapons.length + character.inventoryItems.length + character.spells.length === 0;
+  const nothingToGive = coinsHeld.length === 0 && character.weapons.length + character.inventoryItems.length + character.spells.length === 0;
 
   function handleGive() {
     const gift: Gift | null =
       kind === 'gold'
-        ? { kind, amount: count }
+        ? { kind, amount: count, currency: coin }
         : kind === 'weapon' || kind === 'item'
           ? { kind, id, quantity: count }
           : kind === 'spell'
@@ -145,7 +171,11 @@ function GiveCard({ character, onError }: { character: CharacterDetail; onError:
             style={{ flex: 2, minWidth: 160 }}
           >
             <option value="">What to give…</option>
-            {gold > 0 && <option value="gold:">Gold ({gold} gp)</option>}
+            {coinsHeld.map((c) => (
+              <option key={c} value={`gold:${c}`}>
+                {COIN_LABELS[c]} ({formatMoney(held(c), c)} held)
+              </option>
+            ))}
             {character.weapons.length > 0 && (
               <optgroup label="Weapons">
                 {character.weapons.map((w) => (
@@ -178,8 +208,8 @@ function GiveCard({ character, onError }: { character: CharacterDetail; onError:
             <NumberInput
               min={1}
               max={max}
-              aria-label={kind === 'gold' ? 'How much gold' : 'How many'}
-              title={kind === 'gold' ? 'How much gold' : `How many (up to ${max})`}
+              aria-label={kind === 'gold' ? 'How many coins' : 'How many'}
+              title={`How many (up to ${max})`}
               value={amount}
               onChange={(e) => setAmount(e.target.value)}
               style={{ width: 90 }}
@@ -207,6 +237,7 @@ export function CharacterSheetPage() {
   const { characterId = '' } = useParams();
   const { user } = useAuth();
   const { data: character, isLoading, error } = useCharacter(characterId);
+  useRememberCampaign(character?.campaignId);
   const patchCharacter = usePatchCharacter(characterId);
   useCampaignSocket(character?.campaignId);
 
@@ -228,6 +259,7 @@ export function CharacterSheetPage() {
   const patchSpell = usePatchCharacterSpell(characterId);
   const removeSpell = useRemoveCharacterSpell(characterId);
   const adjustGold = useAdjustGold(characterId);
+  const exchangeCoins = useExchangeCoins(characterId);
   const createNote = useCreateNote();
   const { data: campaigns } = useCampaigns();
   const copyCharacter = useCopyCharacter(characterId);
@@ -237,6 +269,10 @@ export function CharacterSheetPage() {
   const [pickedItemId, setPickedItemId] = useState('');
   const [goldAmount, setGoldAmount] = useState('');
   const [goldReason, setGoldReason] = useState('');
+  const [goldCurrency, setGoldCurrency] = useState<Currency>('GOLD');
+  const [exchangeAmount, setExchangeAmount] = useState('');
+  const [exchangeFrom, setExchangeFrom] = useState<Coin>('GOLD');
+  const [exchangeTo, setExchangeTo] = useState<Coin>('SILVER');
   const [noteBody, setNoteBody] = useState('');
   const [pickedWeaponId, setPickedWeaponId] = useState('');
   const [pickedSpellId, setPickedSpellId] = useState('');
@@ -273,7 +309,9 @@ export function CharacterSheetPage() {
     const amount = Number(hpDelta);
     if (!amount) return;
     const next = character!.currentHp + sign * amount;
-    patchCharacter.mutate({ currentHp: next });
+    setFormError(null);
+    // Healing is refused for a character who has died.
+    patchCharacter.mutate({ currentHp: next }, { onError: (err) => setFormError(extractErrorMessage(err)) });
     setHpDelta('');
   }
 
@@ -300,7 +338,7 @@ export function CharacterSheetPage() {
     if (!(amount > 0)) return;
     setFormError(null);
     try {
-      await adjustGold.mutateAsync({ amount: sign * amount, reason: goldReason.trim() || undefined });
+      await adjustGold.mutateAsync({ amount: sign * amount, currency: goldCurrency, reason: goldReason.trim() || undefined });
       setGoldAmount('');
       setGoldReason('');
     } catch (err) {
@@ -308,6 +346,18 @@ export function CharacterSheetPage() {
     }
   }
 
+  async function handleExchange() {
+    const amount = Math.floor(Number(exchangeAmount));
+    if (!(amount > 0) || exchangeFrom === exchangeTo) return;
+    setFormError(null);
+    try {
+      await exchangeCoins.mutateAsync({ from: exchangeFrom, to: exchangeTo, amount });
+      setExchangeAmount('');
+    } catch (err) {
+      setFormError(extractErrorMessage(err));
+    }
+  }
+
   async function handleAddNote(e: FormEvent) {
     e.preventDefault();
     if (!noteBody.trim()) return;
@@ -415,6 +465,14 @@ export function CharacterSheetPage() {
       </div>
 
       <HpBar current={character.currentHp} max={sheet.hp.max} temp={character.tempHp} />
+      <DeathSaves
+        characterId={characterId}
+        name={character.name}
+        deathSaves={character.deathSaves}
+        canAct={canEdit}
+        isDM={isDM}
+        onError={(err) => setFormError(extractErrorMessage(err))}
+      />
 
       {canEdit && (
         <div className="flex-row mt-sm flex-wrap">
@@ -497,7 +555,9 @@ export function CharacterSheetPage() {
         <p className="subtitle mt-sm">📍 Currently at: <strong>{character.currentLocation.name}</strong></p>
       )}
 
-      <div className="card mt-md">
+      <JumpNav />
+
+      <div data-jump="Abilities" className="card mt-md">
         <div className="card-title">Ability Scores</div>
         <div className="grid grid-cols-3">
           {(Object.keys(sheet.abilities) as Ability[]).map((ability) => (
@@ -513,7 +573,7 @@ export function CharacterSheetPage() {
       </div>
 
       <div className="grid grid-cols-2 mt-md">
-        <div className="card">
+        <div data-jump="Saves" className="card">
           <div className="card-title">
             Saving Throws <InfoTip term="SAVING_THROW" />
           </div>
@@ -526,7 +586,7 @@ export function CharacterSheetPage() {
             </div>
           ))}
         </div>
-        <div className="card">
+        <div data-jump="Skills" className="card">
           <div className="card-title">
             Skills <InfoTip term="SKILL_BONUS" />
           </div>
@@ -560,7 +620,7 @@ export function CharacterSheetPage() {
         </div>
       )}
 
-      <div className="card mt-md">
+      <div data-jump="Weapons" className="card mt-md">
         <div className="card-title">
           Weapons <InfoTip term="ATTACK_BONUS" />
         </div>
@@ -623,7 +683,7 @@ export function CharacterSheetPage() {
       </div>
 
       {campaignSpells && campaignSpells.length > 0 && (
-        <div className="card mt-md">
+        <div data-jump="Spells" className="card mt-md">
           <div className="card-title">Spells Known</div>
           {spellsPage.pageItems.map((cs) => (
             <div key={cs.id} className="flex-between" style={{ padding: '0.4rem 0', borderBottom: '1px solid var(--border-soft)' }}>
@@ -687,7 +747,7 @@ export function CharacterSheetPage() {
 
       {!character.restricted && (
         <>
-      <div className="card mt-md">
+      <div data-jump="Inventory" className="card mt-md">
         <div className="card-title">Inventory</div>
         {itemsPage.pageItems.map((held) => (
           <div key={held.id} className="flex-between" style={{ padding: '0.4rem 0', borderBottom: '1px solid var(--border-soft)' }}>
@@ -767,22 +827,34 @@ export function CharacterSheetPage() {
         )}
       </div>
 
-      <div className="card mt-md">
+      <div data-jump="Money" className="card mt-md">
         <div className="card-title">
           <span>Money</span>
-          <span className="mono">{character.gold} gp</span>
+          <span className="mono">{formatPurse(character)}</span>
         </div>
+        <p className="subtitle" style={{ marginTop: 0 }}>
+          1 gold = 10 silver = 100 copper. Worth {purseWorthInGold(character)} gold in all. Spending and giving make
+          change for you: if you are short of a coin, a bigger one is broken. Cash ($) is kept apart: it is never
+          exchanged for coins.
+        </p>
         {canEdit && (
           <div className="flex-row flex-wrap">
             <NumberInput
               min={1}
               max={1000000}
               placeholder="Amount"
-              aria-label="Gold amount"
+              aria-label="Coin amount"
               value={goldAmount}
               onChange={(e) => setGoldAmount(e.target.value)}
               style={{ width: 100 }}
             />
+            <select aria-label="Coin" value={goldCurrency} onChange={(e) => setGoldCurrency(e.target.value as Currency)}>
+              {CURRENCIES.map((c) => (
+                <option key={c} value={c}>
+                  {COIN_LABELS[c]}
+                </option>
+              ))}
+            </select>
             <input
               placeholder="What for? (optional)"
               aria-label="Reason"
@@ -799,19 +871,56 @@ export function CharacterSheetPage() {
             </button>
           </div>
         )}
+        {canEdit && (
+          <div className="flex-row flex-wrap mt-sm">
+            <span className="subtitle">Exchange</span>
+            <NumberInput
+              min={1}
+              max={1000000}
+              placeholder="Amount"
+              aria-label="How many coins to exchange"
+              value={exchangeAmount}
+              onChange={(e) => setExchangeAmount(e.target.value)}
+              style={{ width: 100 }}
+            />
+            <select aria-label="Exchange from" value={exchangeFrom} onChange={(e) => setExchangeFrom(e.target.value as Coin)}>
+              {COINS.map((c) => (
+                <option key={c} value={c}>
+                  {COIN_LABELS[c]}
+                </option>
+              ))}
+            </select>
+            <span className="subtitle">into</span>
+            <select aria-label="Exchange into" value={exchangeTo} onChange={(e) => setExchangeTo(e.target.value as Coin)}>
+              {COINS.map((c) => (
+                <option key={c} value={c}>
+                  {COIN_LABELS[c]}
+                </option>
+              ))}
+            </select>
+            <button className="btn" onClick={handleExchange} disabled={!exchangeAmount || exchangeFrom === exchangeTo || exchangeCoins.isPending}>
+              Exchange
+            </button>
+          </div>
+        )}
         <div className="mt-sm">
           {goldLedger?.length === 0 && <p style={{ color: 'var(--text-muted)' }}>No transactions yet.</p>}
           {ledgerPage.pageItems.map((t) => (
             <div key={t.id} className="flex-between" style={{ padding: '0.4rem 0', borderBottom: '1px solid var(--border-soft)' }}>
               <div>
-                <strong className="mono">{t.amount > 0 ? `+${t.amount}` : `−${Math.abs(t.amount)}`}</strong>
+                <strong className="mono">
+                  {t.amount > 0 ? '+' : '−'}
+                  {formatMoney(Math.abs(t.amount), t.currency ?? 'GOLD')}
+                </strong>
                 <span style={{ marginLeft: 8 }}>{t.reason || (t.amount > 0 ? 'Gained' : 'Spent')}</span>
                 <div style={{ fontSize: '0.75rem', color: 'var(--text-dim)' }}>
                   {t.createdBy ? `${t.createdBy.displayName} · ` : ''}
                   {new Date(t.createdAt).toLocaleString()}
                 </div>
               </div>
-              <span className="mono" style={{ color: 'var(--text-muted)' }}>{t.balanceAfter} gp</span>
+              <span className="mono" style={{ color: 'var(--text-muted)' }}>
+                {formatMoney(t.balanceAfter, t.currency ?? 'GOLD')}
+              </span>
             </div>
           ))}
         </div>
@@ -895,7 +1004,7 @@ export function CharacterSheetPage() {
         </div>
       )}
 
-      <div className="card mt-md">
+      <div data-jump="Notes" className="card mt-md">
         <div className="card-title">Notes</div>
         <form onSubmit={handleAddNote} className="flex-row flex-wrap">
           <textarea

frontend/src/pages/EncounterPage.tsx

@@ -14,6 +14,8 @@ import {
   useRemoveParticipant,
   useAdvanceRound,
   useNextTurn,
+  useSetTargets,
+  useReviveParticipant,
   usePatchEncounter,
   useSetEncounterArchived,
   useDeleteEncounter,
@@ -27,11 +29,15 @@ import { useAuth } from '../auth/AuthContext';
 import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
 import { HpBar } from '../components/HpBar';
-import { ABILITY_LABELS, CLASS_LABELS, SPECIES_LABELS, extractErrorMessage, fmtMod, spellLevelLabel } from '../lib/format';
+import { DeathSaves } from '../components/DeathSaves';
+import { TradePanel } from '../components/TradePanel';
+import { useRememberCampaign } from '../lib/lastCampaign';
+import { ABILITY_LABELS, CLASS_LABELS, COIN_LABELS, CURRENCIES, SPECIES_LABELS, extractErrorMessage, fmtMod, formatMoney, spellLevelLabel } from '../lib/format';
 import { abilityModifier, scaledDamageDice, MAX_GEAR_LEVEL } from '../lib/previewCalc';
 import type {
   Ability,
   CharacterSummary,
+  Currency,
   Encounter,
   EncounterMode,
   EncounterParticipant,
@@ -60,6 +66,11 @@ const CONDITIONS = [
   'Concentrating',
 ];
 
+// An attack on more than one target is an area attack, and harder to land:
+// every target's AC counts as `step` higher for each target beyond the first.
+// The step is the campaign's "area attack AC penalty" setting.
+const areaPenalty = (targetCount: number, step: number) => Math.max(0, targetCount - 1) * step;
+
 const KIND_LABELS = { CHARACTER: 'PC', MONSTER: 'Monster', NPC: 'NPC' } as const;
 const KIND_BADGES = { CHARACTER: 'badge-player', MONSTER: 'badge-hostile', NPC: 'badge-friendly' } as const;
 const MODE_LABELS: Record<EncounterMode, string> = { BATTLE: '⚔ Battle', QUEST: '📜 Quest' };
@@ -94,20 +105,32 @@ function subline(p: EncounterParticipant): string {
 function CombatantCard({
   participant: p,
   isDM,
-  mode,
   isActive,
   onPatch,
   canRollInitiative,
+  targetedBy,
+  acPenalty,
+  onTarget,
   onRemove,
+  onError,
 }: {
   participant: EncounterParticipant;
   isDM: boolean;
-  mode: EncounterMode;
   isActive: boolean;
   onPatch: (data: Partial<EncounterParticipant>) => void;
-  // The DM for anyone; a player for their own character.
+  // The DM for anyone; a player for their own character. The same goes for
+  // that character's death saves.
   canRollInitiative: boolean;
+  // Set while this combatant is a target: who is going for them, or '' when
+  // nobody is on turn.
+  targetedBy?: string;
+  // What an area attack adds to this target's AC; 0 when they are the only one.
+  acPenalty: number;
+  // Marks this combatant as a target, or unmarks them. Absent for someone who
+  // may not pick targets right now, and on the card of whoever is on turn.
+  onTarget?: () => void;
   onRemove: () => void;
+  onError: (err: unknown) => void;
 }) {
   const [hpDelta, setHpDelta] = useState('');
   // Details start open for the DM (who runs the scene from this screen) and
@@ -126,6 +149,9 @@ function CombatantCard({
   const tracksHp = barOnly || maxHp > 0;
   const pct = barOnly ? (p.hpPercent ?? 0) : tracksHp ? Math.max(0, Math.min(100, (currentHp / maxHp) * 100)) : 0;
   const isDown = tracksHp && pct <= 0;
+  // A dying character still has something to do each turn, so its card stays lit.
+  const isDying = info?.deathSaves.state === 'DYING';
+  const isTargeted = targetedBy !== undefined;
   // Players get a monster's name and health bar only; the stat block is the DM's.
   const monsterStats = monster && monster.ac !== undefined ? monster : null;
   const hasDetails = Boolean(info || monsterStats || npc?.dmNotes);
@@ -144,10 +170,16 @@ function CombatantCard({
   }
 
   return (
-    <div className={`card combatant combatant-${p.kind.toLowerCase()}${isActive ? ' is-active' : ''}${isDown ? ' is-down' : ''}`}>
+    <div className={`card combatant combatant-${p.kind.toLowerCase()}${isActive ? ' is-active' : ''}${isDown && !isDying ? ' is-down' : ''}${isTargeted ? ' is-targeted' : ''}`}>
       <div className="flex-between flex-wrap">
         <div>
           {isActive && <div className="turn-marker">▶ On turn</div>}
+          {isTargeted && (
+            <div className="target-marker">
+              🎯 Targeted{targetedBy && ` by ${targetedBy}`}
+              {acPenalty > 0 && ` · area attack, AC +${acPenalty}`}
+            </div>
+          )}
           <div className="flex-row flex-wrap">
             <span className={`badge ${KIND_BADGES[p.kind]}`}>{KIND_LABELS[p.kind]}</span>
             {p.character ? (
@@ -158,12 +190,27 @@ function CombatantCard({
               <span className="combatant-name">{p.displayName}</span>
             )}
             {npc && <span className={`badge badge-${npc.disposition.toLowerCase()}`}>{npc.disposition}</span>}
-            {isDown && <span className="badge badge-hostile">Down</span>}
+            {isDown && !info && <span className="badge badge-hostile">Down</span>}
+            {p.hidden && (
+              <span className="badge" title="Out of the fight. Players no longer see this card, and it has no turn.">
+                Hidden from players
+              </span>
+            )}
+            {onTarget && (
+              <button
+                className={`btn btn-target${isTargeted ? ' is-on' : ''}`}
+                aria-pressed={isTargeted}
+                title={isTargeted ? 'Stop targeting' : `Mark ${p.displayName} as a target. Marking more than one makes it an area attack.`}
+                onClick={onTarget}
+              >
+                🎯 {isTargeted ? 'Targeted' : 'Target'}
+              </button>
+            )}
           </div>
           <div className="combatant-sub">{subline(p)}</div>
         </div>
-        {mode === 'BATTLE' &&
-          (canRollInitiative ? (
+        {/* Battles and quests both take initiative: who speaks or acts first matters in either. */}
+        {canRollInitiative ? (
             <label className="flex-row gap-sm" title="Type what the d20 showed (1 to 20). The initiative bonus is added for you.">
               Initiative roll
               <NumberInput
@@ -186,7 +233,7 @@ function CombatantCard({
             </label>
           ) : (
             <StatChip label="Initiative">{p.initiativeRoll == null ? '—' : p.initiative}</StatChip>
-          ))}
+          )}
       </div>
 
       <div className="stat-chips mt-sm">
@@ -244,6 +291,16 @@ function CombatantCard({
               </button>
             </div>
           )}
+          {info && p.character && (
+            <DeathSaves
+              characterId={p.character.id}
+              name={p.displayName}
+              deathSaves={info.deathSaves}
+              canAct={canRollInitiative}
+              isDM={isDM}
+              onError={onError}
+            />
+          )}
         </>
       )}
 
@@ -380,8 +437,178 @@ function CombatantCard({
   );
 }
 
+// What a combatant hits with, one line per attack: a character's weapons
+// (the equipped ones, when any are) and damaging spells, or the single attack
+// of a monster or NPC.
+function attackLines(p: EncounterParticipant): string[] {
+  const info = p.characterCombatInfo;
+  if (info) {
+    const equipped = info.weapons.filter((w) => w.equipped);
+    const weapons = (equipped.length ? equipped : info.weapons).map(
+      (w) => `${w.name}: ${fmtMod(w.attackBonus)} to hit · ${w.damageDice} ${fmtMod(w.damageBonus)} ${w.damageType}`
+    );
+    const spells = info.spells
+      .filter((s) => s.damageDice)
+      .map((s) => `${s.name}: ${s.damageDice}${info.spellcasting ? ` · ${fmtMod(info.spellcasting.attackBonus)} to hit / DC ${info.spellcasting.saveDC}` : ''}`);
+    return [...weapons, ...spells];
+  }
+  const stats = p.monster ?? p.npc;
+  if (!stats || (stats.attackBonus == null && !stats.damageDice)) return [];
+  return [[stats.attackBonus != null && `${fmtMod(stats.attackBonus)} to hit`, stats.damageDice].filter(Boolean).join(' · ')];
+}
+
+type AreaMode = 'SPLIT' | 'EACH';
+
+// How `amount` lands on `count` targets: all of it on each, or shared out
+// evenly, any remainder going one point each to the first targets picked
+// (7 between three is 3, 2 and 2).
+function shares(amount: number, count: number, mode: AreaMode): number[] {
+  if (mode === 'EACH') return Array.from({ length: count }, () => amount);
+  const base = Math.floor(amount / count);
+  return Array.from({ length: count }, (_, i) => base + (i < amount % count ? 1 : 0));
+}
+
+// The DM's shortcut once targets are marked: who is attacking whom, the
+// numbers needed to call the hit, and a box to apply the damage without
+// hunting for each target's card. With more than one target it is an area
+// attack: each AC is shown with the penalty added, the DM ticks who was hit,
+// and the amount is split between them or dealt to each in full.
+function AttackBar({
+  attacker,
+  targets,
+  acStep,
+  onApply,
+  onRemove,
+  onClear,
+}: {
+  attacker: EncounterParticipant | undefined;
+  targets: EncounterParticipant[];
+  acStep: number; // the campaign's area attack AC penalty
+  onApply: (changes: { participantId: string; currentHp: number }[]) => void;
+  onRemove: (participantId: string) => void;
+  onClear: () => void;
+}) {
+  const [amount, setAmount] = useState('');
+  const [mode, setMode] = useState<AreaMode>('SPLIT');
+  const [missed, setMissed] = useState<string[]>([]);
+
+  const isArea = targets.length > 1;
+  const penalty = areaPenalty(targets.length, acStep);
+  const tracksHp = (t: EncounterParticipant) => (t.maxHp ?? 0) > 0;
+  const hit = targets.filter((t) => tracksHp(t) && !missed.includes(t.id));
+  const value = Number(amount) || 0;
+  const portions = shares(value, hit.length, isArea ? mode : 'EACH');
+  const attacks = attacker ? attackLines(attacker) : [];
+
+  function apply(sign: 1 | -1) {
+    if (!value || hit.length === 0) return;
+    onApply(hit.map((t, i) => ({ participantId: t.id, currentHp: (t.currentHp ?? 0) + sign * portions[i] })));
+    setAmount('');
+    setMissed([]);
+  }
+
+  return (
+    <div className="card attack-bar">
+      <div className="flex-between flex-wrap">
+        <div className="attack-bar-title">
+          {attacker && <>{attacker.displayName} → </>}🎯 {isArea ? `${targets.length} targets` : targets[0].displayName}
+        </div>
+        <button className="btn btn-ghost" onClick={onClear}>
+          ✕ Clear {isArea ? 'targets' : 'target'}
+        </button>
+      </div>
+      {isArea && (
+        <p className="combatant-sub" style={{ margin: '0.25rem 0 0' }}>
+          Area attack{penalty > 0 && `: every target's AC counts as ${penalty} higher (+${acStep} for each target beyond the first)`}. Untick anyone the
+          roll missed.
+        </p>
+      )}
+
+      {targets.map((t) => {
+        const info = t.characterCombatInfo;
+        const ac = info?.armorClass ?? t.monster?.ac ?? t.npc?.ac;
+        const portion = portions[hit.indexOf(t)];
+        return (
+          <div key={t.id} className="attack-target">
+            {isArea && (
+              <label className="flex-row gap-sm">
+                <input
+                  type="checkbox"
+                  aria-label={`${t.displayName} was hit`}
+                  disabled={!tracksHp(t)}
+                  checked={hit.includes(t)}
+                  onChange={(e) => setMissed(e.target.checked ? missed.filter((id) => id !== t.id) : [...missed, t.id])}
+                />
+                <span className="attack-target-name">{t.displayName}</span>
+              </label>
+            )}
+            <div className="stat-chips">
+              {ac != null && (
+                <StatChip label={isArea ? 'AC to beat' : 'Target AC'}>
+                  {ac + penalty}
+                  {penalty > 0 && ` (${ac} +${penalty})`}
+                </StatChip>
+              )}
+              {tracksHp(t) ? (
+                <StatChip label={isArea ? 'HP' : 'Target HP'}>
+                  {t.currentHp ?? 0}/{t.maxHp}
+                  {info && info.tempHp > 0 && ` +${info.tempHp}`}
+                </StatChip>
+              ) : (
+                <span className="combatant-sub">No hit points to track.</span>
+              )}
+              {isArea && value > 0 && portion !== undefined && <StatChip label="Share">{portion}</StatChip>}
+            </div>
+            {isArea && (
+              <button className="btn btn-ghost" aria-label={`Stop targeting ${t.displayName}`} onClick={() => onRemove(t.id)}>
+                ✕
+              </button>
+            )}
+          </div>
+        );
+      })}
+
+      {attacks.map((line) => (
+        <div key={line} className="combatant-sub mt-sm">
+          ⚔ {line}
+        </div>
+      ))}
+
+      {targets.some(tracksHp) && (
+        <div className="flex-row flex-wrap gap-sm mt-sm">
+          {/* Remounted when the targets change, so the cursor lands here as soon as one is marked. */}
+          <NumberInput
+            key={targets.map((t) => t.id).join()}
+            autoFocus
+            min={1}
+            max={99999}
+            placeholder={isArea ? 'Total' : 'Amount'}
+            aria-label={isArea ? 'HP change for the targets hit' : `HP change for ${targets[0].displayName}`}
+            value={amount}
+            onChange={(e) => setAmount(e.target.value)}
+            onKeyDown={(e) => e.key === 'Enter' && apply(-1)}
+            style={{ width: 90 }}
+          />
+          {isArea && (
+            <select aria-label="How the amount is shared" value={mode} onChange={(e) => setMode(e.target.value as AreaMode)} style={{ width: 'auto' }}>
+              <option value="SPLIT">Split between those hit</option>
+              <option value="EACH">Full amount to each</option>
+            </select>
+          )}
+          <button className="btn btn-danger" onClick={() => apply(-1)} disabled={!value || hit.length === 0}>
+            − Damage
+          </button>
+          <button className="btn" onClick={() => apply(1)} disabled={!value || hit.length === 0}>
+            + Heal
+          </button>
+        </div>
+      )}
+    </div>
+  );
+}
+
 function rewardLabel(r: EncounterReward): string {
-  if (r.type === 'GOLD') return `${r.gold} gold`;
+  if (r.type === 'GOLD') return formatMoney(r.gold ?? 0, r.currency ?? 'GOLD', true);
   const entry = r.type === 'WEAPON' ? r.weapon : r.item;
   return `${entry?.name ?? 'Removed from the pool'}${r.quantity > 1 ? ` ×${r.quantity}` : ''} · Lv ${r.level}`;
 }
@@ -407,6 +634,7 @@ function RewardsPanel({
 
   const [type, setType] = useState<NewReward['type']>('GOLD');
   const [gold, setGold] = useState('');
+  const [currency, setCurrency] = useState<Currency>('GOLD');
   const [poolId, setPoolId] = useState('');
   const [quantity, setQuantity] = useState('1');
   const [level, setLevel] = useState('');
@@ -426,7 +654,7 @@ function RewardsPanel({
     if (type === 'GOLD') {
       const amount = Math.floor(Number(gold));
       if (!(amount > 0)) return;
-      reward = { type, gold: amount, ...shared };
+      reward = { type, gold: amount, currency, ...shared };
     } else {
       if (!picked) return;
       const gear = { quantity: Math.max(1, Math.floor(Number(quantity)) || 1), level: level ? Number(level) : undefined, ...shared };
@@ -449,7 +677,7 @@ function RewardsPanel({
       <div className="card-title">Rewards</div>
       {isDM && rewards.length === 0 && (
         <p className="combatant-sub" style={{ marginTop: 0 }}>
-          Line up gold, weapons and items here. Players only see a reward once you award it.
+          Line up coins, weapons and items here. Players only see a reward once you award it.
         </p>
       )}
       {rewards.map((r) => (
@@ -519,20 +747,29 @@ function RewardsPanel({
                 setLevel('');
               }}
             >
-              <option value="GOLD">Gold</option>
+              <option value="GOLD">Coins</option>
               <option value="WEAPON">Weapon</option>
               <option value="ITEM">Item</option>
             </select>
             {type === 'GOLD' ? (
-              <NumberInput
-                min={1}
-                max={1000000}
-                placeholder="Amount"
-                aria-label="Gold amount"
-                value={gold}
-                onChange={(e) => setGold(e.target.value)}
-                style={{ flex: 1, minWidth: 90 }}
-              />
+              <>
+                <NumberInput
+                  min={1}
+                  max={1000000}
+                  placeholder="Amount"
+                  aria-label="Coin amount"
+                  value={gold}
+                  onChange={(e) => setGold(e.target.value)}
+                  style={{ flex: 1, minWidth: 90 }}
+                />
+                <select aria-label="Coin" value={currency} onChange={(e) => setCurrency(e.target.value as Currency)}>
+                  {CURRENCIES.map((c) => (
+                    <option key={c} value={c}>
+                      {COIN_LABELS[c]}
+                    </option>
+                  ))}
+                </select>
+              </>
             ) : (
               <>
                 <select
@@ -599,6 +836,7 @@ export function EncounterPage() {
   const { user } = useAuth();
   const { data: encounter, isLoading, error } = useEncounter(encounterId);
   useCampaignSocket(encounter?.campaignId);
+  useRememberCampaign(encounter?.campaignId);
 
   const { data: campaignData } = useCampaign(encounter?.campaignId);
   const isDM = campaignData?.campaign.role === 'DM';
@@ -614,6 +852,8 @@ export function EncounterPage() {
   const removeParticipant = useRemoveParticipant(encounterId);
   const advanceRound = useAdvanceRound(encounterId);
   const nextTurn = useNextTurn(encounterId);
+  const setTargets = useSetTargets(encounterId);
+  const revive = useReviveParticipant(encounterId);
   const patchEncounter = usePatchEncounter(encounterId);
   const setArchived = useSetEncounterArchived(encounter?.campaignId ?? '');
   const deleteEncounter = useDeleteEncounter(encounter?.campaignId ?? '');
@@ -623,20 +863,39 @@ export function EncounterPage() {
   const [pickId, setPickId] = useState('');
   const [initiative, setInitiative] = useState('');
   const [formError, setFormError] = useState<string | null>(null);
+  // The DM's own screen leaves the fallen out too, until asked for.
+  const [showDead, setShowDead] = useState(false);
 
   if (isLoading) return <Spinner label="Setting the scene…" />;
   if (error || !encounter) return <ErrorBanner message="Could not load this encounter." />;
 
   const isBattle = encounter.mode === 'BATTLE';
   const participants = encounter.participants ?? []; // already in initiative order
+  // The fallen: dead characters, and monsters and NPCs at 0 HP. Only the DM is
+  // sent their cards, and they sit apart from those still in the fight.
+  const standing = participants.filter((p) => !p.hidden);
+  const outOfTheFight = participants.filter((p) => p.hidden);
+  const fallen = encounter.fallen ?? [];
   const active = isBattle && encounter.status === 'ACTIVE' ? participants.find((p) => p.id === encounter.activeParticipantId) : undefined;
+  const targetIds = encounter.targetParticipantIds ?? [];
+  const targets = targetIds.map((id) => participants.find((p) => p.id === id)).filter((p): p is EncounterParticipant => p !== undefined);
+  // The DM marks targets whenever they like; a player while their own character is on turn.
+  const acStep = campaignData?.campaign.areaAttackAcPenalty ?? 0;
+  const canTarget = isDM || (active?.character != null && active.character.userId === user?.id);
+  // A player whose own character is on turn, on their feet and able to raise the dead.
+  const canTryRevive =
+    active?.character != null &&
+    active.character.userId === user?.id &&
+    active.characterCombatInfo?.deathSaves.state === 'UP' &&
+    active.characterCombatInfo.canRevive;
   const builtCharacters = characters?.filter((c) => c.buildStage === 'COMPLETE') ?? [];
   const onError = (err: unknown) => setFormError(extractErrorMessage(err));
   const fail = { onError };
 
   const pickOptions: { id: string; name: string }[] =
     pickType === 'character'
-      ? builtCharacters.filter((c) => !participants.some((p) => p.characterId === c.id))
+      ? // The dead join no new scene until they are revived.
+        builtCharacters.filter((c) => c.deathSaves.state !== 'DEAD' && !participants.some((p) => p.characterId === c.id))
       : pickType === 'monster'
         ? (monsters ?? [])
         : (npcs ?? []).filter((n) => !participants.some((p) => p.npcId === n.id));
@@ -655,22 +914,42 @@ export function EncounterPage() {
       key={p.id}
       participant={p}
       isDM={isDM}
-      mode={encounter.mode}
       isActive={p.id === active?.id}
       onPatch={(data) => patchParticipant.mutate({ participantId: p.id, ...data }, fail)}
       canRollInitiative={isDM || (p.character != null && p.character.userId === user?.id)}
+      targetedBy={targetIds.includes(p.id) ? (active?.displayName ?? '') : undefined}
+      acPenalty={areaPenalty(targets.length, acStep)}
+      onTarget={
+        // Nobody targets themselves: the combatant on turn has no button.
+        canTarget && p.id !== active?.id
+          ? () => setTargets.mutate(targetIds.includes(p.id) ? targetIds.filter((id) => id !== p.id) : [...targetIds, p.id], fail)
+          : undefined
+      }
       onRemove={() => removeParticipant.mutate(p.id, fail)}
+      onError={onError}
     />
   );
 
-  // A quest scene is grouped by who is there rather than by initiative.
+  // In a battle under way the turn passes down the initiative order, so
+  // everyone above whoever is on turn has had their go this round. They drop
+  // to "Next Round" at the bottom, which leaves the combatant on turn at the
+  // top with those still to act beneath them. A new round puts everyone back.
+  const turnIndex = active ? participants.indexOf(active) : -1;
+  const hasActed = (p: EncounterParticipant) => participants.indexOf(p) < turnIndex;
+
+  // A quest scene is grouped by who is there; within each group the order is
+  // still initiative, highest first.
   const groups: [string, EncounterParticipant[]][] = isBattle
-    ? [['Initiative order', participants]]
+    ? [
+        ['Initiative order', standing.filter((p) => !hasActed(p))],
+        ['Next Round', standing.filter(hasActed)],
+      ]
     : [
-        ['People you meet', participants.filter((p) => p.kind === 'NPC')],
-        ['The party', participants.filter((p) => p.kind === 'CHARACTER')],
-        ['Creatures', participants.filter((p) => p.kind === 'MONSTER')],
+        ['People you meet', standing.filter((p) => p.kind === 'NPC')],
+        ['The party', standing.filter((p) => p.kind === 'CHARACTER')],
+        ['Creatures', standing.filter((p) => p.kind === 'MONSTER')],
       ];
+  if (showDead) groups.push(['Out of the fight, hidden from players', outOfTheFight]);
 
   return (
     <div>
@@ -793,7 +1072,51 @@ export function EncounterPage() {
 
       <div className="encounter-layout mt-md">
         <div>
-          {participants.length === 0 && (
+          {isDM && targets.length > 0 && (
+            <AttackBar
+              attacker={active}
+              targets={targets}
+              acStep={acStep}
+              onApply={(changes) => Promise.all(changes.map((change) => patchParticipant.mutateAsync(change))).catch(onError)}
+              onRemove={(id) => setTargets.mutate(targetIds.filter((x) => x !== id), fail)}
+              onClear={() => setTargets.mutate([], fail)}
+            />
+          )}
+          {!isDM && fallen.length > 0 && (
+            <div className="card fallen-bar">
+              <div className="card-title">☠ Fallen</div>
+              {fallen.map((f) => (
+                <div key={f.participantId} className="flex-between flex-wrap">
+                  <span className="combatant-name">{f.name}</span>
+                  {canTryRevive && (
+                    <button
+                      className="btn"
+                      title={`${active?.displayName} tries to bring ${f.name} back, at 1 HP.`}
+                      disabled={revive.isPending}
+                      onClick={() => {
+                        setFormError(null);
+                        revive.mutate(f.participantId, fail);
+                      }}
+                    >
+                      Try revive
+                    </button>
+                  )}
+                </div>
+              ))}
+              <p className="combatant-sub" style={{ margin: '0.4rem 0 0' }}>
+                {canTryRevive
+                  ? `${active?.displayName} has a spell that can bring back the dead.`
+                  : 'A character with a spell that brings back the dead can try to revive them on their own turn.'}
+              </p>
+            </div>
+          )}
+          {isDM && outOfTheFight.length > 0 && (
+            <label className="checkbox-row mt-md" title="Dead characters, and monsters and NPCs at 0 HP. Players never see them.">
+              <input type="checkbox" checked={showDead} onChange={(e) => setShowDead(e.target.checked)} />
+              Show dead ({outOfTheFight.length})
+            </label>
+          )}
+          {participants.length === 0 && fallen.length === 0 && (
             <div className="empty-state card">
               {isDM
                 ? 'Nobody here yet. Add characters, monsters or NPCs from the panel alongside.'
@@ -839,18 +1162,16 @@ export function EncounterPage() {
                 </select>
               </div>
               <div className="flex-row gap-sm mt-sm">
-                {isBattle && (
-                  <NumberInput
-                    min={1}
-                    max={20}
-                    placeholder="Initiative roll (d20)"
-                    title="What the d20 showed, 1 to 20. Leave empty to roll later; the bonus is added for you."
-                    aria-label="Initiative roll"
-                    value={initiative}
-                    onChange={(e) => setInitiative(e.target.value)}
-                    style={{ flex: 1, minWidth: 0 }}
-                  />
-                )}
+                <NumberInput
+                  min={1}
+                  max={20}
+                  placeholder="Initiative roll (d20)"
+                  title="What the d20 showed, 1 to 20. Leave empty to roll later; the bonus is added for you."
+                  aria-label="Initiative roll"
+                  value={initiative}
+                  onChange={(e) => setInitiative(e.target.value)}
+                  style={{ flex: 1, minWidth: 0 }}
+                />
                 <button className="btn btn-primary" onClick={handleAdd} disabled={!pickId || addParticipant.isPending}>
                   Add
                 </button>
@@ -863,6 +1184,16 @@ export function EncounterPage() {
             </div>
           )}
 
+          <TradePanel
+            encounter={encounter}
+            isDM={isDM}
+            userId={user?.id}
+            characters={builtCharacters}
+            weapons={weapons ?? []}
+            items={items ?? []}
+            onError={onError}
+          />
+
           <RewardsPanel
             encounter={encounter}
             isDM={isDM}

frontend/src/pages/PartyOverviewPage.tsx

@@ -5,8 +5,9 @@ import { useCampaignSocket } from '../hooks/useCampaignSocket';
 import { Spinner, ErrorBanner } from '../components/Spinner';
 import { usePagination, Pagination } from '../components/Paginated';
 import { InfoTip } from '../components/InfoTip';
-import { CLASS_LABELS, SPECIES_LABELS } from '../lib/format';
+import { CLASS_LABELS, SPECIES_LABELS, formatPurse } from '../lib/format';
 import { HpBar } from '../components/HpBar';
+import { LifeBadge } from '../components/DeathSaves';
 import { speciesIcon } from '../lib/speciesIcons';
 
 // A DM's one-screen view of every character's stats at a glance; a player
@@ -56,7 +57,7 @@ export function PartyOverviewPage() {
                 <th>
                   AC <InfoTip term="AC" />
                 </th>
-                <th>Gold</th>
+                <th>Coins</th>
                 <th>Location</th>
               </tr>
             </thead>
@@ -66,31 +67,32 @@ export function PartyOverviewPage() {
                 const isMine = c.userId === user?.id;
                 return (
                   <tr key={c.id}>
-                    <td>
+                    <td className="cell-title">
                       <Link to={inProgress ? `/characters/${c.id}/build` : `/characters/${c.id}`}>
                         <span aria-hidden="true">{speciesIcon(c.species)}</span> {c.name}
                       </Link>
                       {isMine && <span className="badge" style={{ marginLeft: 6 }}>you</span>}
                     </td>
-                    <td>{c.species ? SPECIES_LABELS[c.species] : '—'}</td>
-                    <td>{c.characterClass ? CLASS_LABELS[c.characterClass] : inProgress ? 'Building…' : '—'}</td>
-                    <td>{c.level}</td>
-                    <td>
+                    <td data-label="Species">{c.species ? SPECIES_LABELS[c.species] : '—'}</td>
+                    <td data-label="Class">{c.characterClass ? CLASS_LABELS[c.characterClass] : inProgress ? 'Building…' : '—'}</td>
+                    <td data-label="Level">{c.level}</td>
+                    <td data-label="HP">
                       {c.maxHp != null ? (
                         <div style={{ minWidth: 90 }}>
                           <span className="mono">
                             {c.currentHp}/{c.maxHp}
                             {c.tempHp > 0 && ` +${c.tempHp}`}
-                          </span>
+                          </span>{' '}
+                          <LifeBadge deathSaves={c.deathSaves} />
                           <HpBar current={c.currentHp} max={c.maxHp} temp={c.tempHp} height={6} />
                         </div>
                       ) : (
                         '—'
                       )}
                     </td>
-                    <td>{c.armorClass ?? '—'}</td>
-                    <td className="mono">{c.gold ?? '—'}</td>
-                    <td>{c.currentLocationName ? `📍 ${c.currentLocationName}` : '—'}</td>
+                    <td data-label="AC">{c.armorClass ?? '—'}</td>
+                    <td data-label="Coins" className="mono">{c.gold == null ? '—' : formatPurse(c)}</td>
+                    <td data-label="Location">{c.currentLocationName ? `📍 ${c.currentLocationName}` : '—'}</td>
                   </tr>
                 );
               })}

package-lock.json

@@ -1,19 +1,19 @@
 {
   "name": "dnd-campaign-manager",
-  "version": "1.3.0",
+  "version": "1.10.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "dnd-campaign-manager",
-      "version": "1.3.0",
+      "version": "1.10.1",
       "workspaces": [
         "backend",
         "frontend"
       ]
     },
     "backend": {
-      "version": "1.3.0",
+      "version": "1.10.1",
       "dependencies": {
         "@prisma/client": "^5.20.0",
         "bcrypt": "^5.1.1",
@@ -31,7 +31,7 @@
       }
     },
     "frontend": {
-      "version": "1.3.0",
+      "version": "1.10.1",
       "dependencies": {
         "@tanstack/react-query": "^5.103.2",
         "axios": "^1.20.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "dnd-campaign-manager",
-  "version": "1.3.0",
+  "version": "1.10.1",
   "private": true,
   "description": "D&D 5e campaign manager — monorepo root",
   "workspaces": [