V1.10.0: NPCs change money and sell things

- An NPC can change gold and cash at a rate of their own ("2 gold = $15"), the same both ways. Only gold and cash are taken: no silver, no copper and no change, and the amount has to be a whole multiple of the rate. - An NPC can sell weapons and items from the campaign pools, each with a price in any coin or in cash, a level and an optional stock. The wares follow the NPC into every quest. An encounter can sell things itself too, for a stall with nobody behind it. - Trading is open only in an NPC quest in progress, never in a battle, with an NPC who is in the scene and standing, for a character who is in it. Players see every rate and ware and trade for their own character in a new Trade card; the DM can trade for anyone. - Only the DM sets trade up: "Trade" on an NPC's row on the campaign page, and the DM's part of the Trade card for an encounter's own wares. A ware's price and stock can be edited afterwards. - Every exchange and purchase is written to the character's money log. - All packages at version 1.10.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
V1.9.0: full monster stat blocks, and cash ($)
2026-10-07 13:45:40 +02:00 · 2026-10-07 13:15:55 +02:00 · 2026-10-06 14:49:44 +02:00 · 2026-10-06 14:25:46 +02:00
33 changed files with 2096 additions and 226 deletions
@@ -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
@@ -1,6 +1,6 @@
 {
  "name": "backend",
-  "version": "1.7.2",
+  "version": "1.10.0",
  "private": true,
  "type": "commonjs",
  "main": "src/index.js",
@@ -10,7 +10,7 @@
  "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",
@@ -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');
@@ -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;
@@ -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;
@@ -118,12 +118,14 @@ enum RewardType {
  ITEM
 }

-// The coins a character carries. Their worth is fixed in utils/grants.js:
-// 1 gold = 10 silver = 100 copper.
+// 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 {
@@ -186,6 +188,7 @@ model Campaign {
  monsters   Monster[]
  npcs       Npc[]
  encounters Encounter[]
+  saleOffers SaleOffer[]
  notes      Note[]
  locations  Location[]

@@ -278,11 +281,12 @@ model Character {
  // 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 is counted on its own and only changes through the
+  // 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?
@@ -369,6 +373,7 @@ model Weapon {
  campaign Campaign          @relation(fields: [campaignId], references: [id], onDelete: Cascade)
  assigned CharacterWeapon[]
  rewards  EncounterReward[]
+  offers   SaleOffer[]

  @@map("weapons")
 }
@@ -403,6 +408,7 @@ model Item {
  campaign Campaign        @relation(fields: [campaignId], references: [id], onDelete: Cascade)
  held     InventoryItem[]
  rewards  EncounterReward[]
+  offers   SaleOffer[]

  @@map("items")
 }
@@ -458,6 +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[]
@@ -521,10 +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")
 }
@@ -559,6 +573,7 @@ model Encounter {
  location     Location?              @relation(fields: [locationId], references: [id], onDelete: SetNull)
  participants EncounterParticipant[]
  rewards      EncounterReward[]
+  wares        SaleOffer[]

  @@map("encounters")
 }
@@ -588,6 +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
@@ -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'] },
 ];
@@ -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 });
  });
 });

@@ -2117,9 +2185,82 @@ describe('death saves', () => {
    // Healed, then hit for max HP more than they have left.
    await strike(max);
    await strike(-max);
-    expect((await combatant()).characterCombatInfo.deathSaves.state).toBe('DEAD');
+    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', () => {
@@ -2264,3 +2405,128 @@ describe('paying with change', () => {
    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([]);
+  });
+});
@@ -8,6 +8,7 @@ const { computeCharacterSheet, MAX_DAMAGE_SCALING, MAX_GEAR_LEVEL } = require('.
 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();

@@ -201,6 +202,7 @@ function characterSummary(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,
@@ -225,7 +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, silver: null, copper: null, ...(knowsPlace ? {} : { currentLocationId: null, currentLocationName: null }) };
+        return { ...c, gold: null, silver: null, copper: null, cash: null, ...(knowsPlace ? {} : { currentLocationId: null, currentLocationName: null }) };
      }),
    });
  } catch (err) {
@@ -405,6 +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) => {
@@ -524,7 +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(),
@@ -643,7 +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);
@@ -660,12 +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) {
@@ -677,8 +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);
@@ -778,6 +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
@@ -29,7 +29,7 @@ const {
 } = require('../game/buildFlow');
 const characterOptions = require('../game/data/characterOptions');
 const { SKILLS } = require('../game/data/skills');
-const { CURRENCIES, COIN_VALUE, COIN_COLUMN, InsufficientGoldError, adjustGold, spendCoins, worthInGold, 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, NO_DEATH_SAVES, lifeState, deathSaveInfo, settleDeathSaves, changeHp, rollDeathSave } = require('../utils/hp');

@@ -97,6 +97,7 @@ function serializeCharacter(character, isOwner, isDM = true) {
    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,
@@ -173,8 +174,8 @@ function clamp(value, min, max) {

 router.patch('/:id', requireCharacterAccess({ write: true }), async (req, res, next) => {
  try {
-    if (req.body && ['gold', 'silver', 'copper'].some((coin) => req.body[coin] !== undefined)) {
-      return res.status(400).json({ error: 'Gold, silver and copper 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() });
@@ -425,6 +426,7 @@ router.post('/:id/copy', requireCharacterAccess(), async (req, res, next) => {
          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
@@ -938,8 +940,11 @@ function coinName(currency) {
  return currency.toLowerCase();
 }

-// For a payment the whole purse can't cover.
+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)}.`;
 }

@@ -951,7 +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, silver: req.character.silver, copper: req.character.copper, transactions });
+    res.json({ gold: req.character.gold, silver: req.character.silver, copper: req.character.copper, cash: req.character.cash, transactions });
  } catch (err) {
    next(err);
  }
@@ -961,6 +966,7 @@ router.get('/:id/gold', requireCharacterAccess(), async (req, res, next) => {
 // 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
@@ -986,7 +992,7 @@ router.post('/:id/gold', requireCharacterAccess({ write: true }), async (req, re
    }

    emitCharacterUpdated(req);
-    const purse = await prisma.character.findUnique({ where: { id: req.character.id }, select: { gold: true, silver: true, copper: true } });
+    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);
@@ -996,11 +1002,12 @@ router.post('/:id/gold', requireCharacterAccess({ write: true }), async (req, re
 // 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.
+// 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(CURRENCIES), to: z.enum(CURRENCIES), amount: z.number().int().min(1).max(1000000) })
+      .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() });
@@ -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 { CURRENCIES, adjustGold, giveGear } = require('../utils/grants');
+const { CURRENCIES, InsufficientGoldError, adjustGold, spendCoins, giveGear } = require('../utils/grants');
 const { moveCharacters, visitedLocationIds } = require('../utils/locations');
-const { lifeState, deathSaveInfo, changeHp } = 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
@@ -104,6 +141,7 @@ function characterCombatInfo(character) {
    maxHp: sheet.hp.max,
    tempHp: character.tempHp,
    deathSaves: deathSaveInfo(character),
+    canRevive: Boolean(revivalSpell(character)),
    speed: sheet.speed,
    initiativeBonus: sheet.initiative,
    passivePerception: sheet.passivePerception,
@@ -117,9 +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
@@ -142,21 +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.
@@ -187,7 +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),
  };
 }
@@ -255,11 +309,10 @@ 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.
@@ -317,6 +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;
@@ -428,16 +485,16 @@ 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, and
-    // their targets go with the turn. Removing a target just unmarks it.
+    // 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 = order.length > 1 ? order[(index + 1) % order.length] : null;
+      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);
@@ -450,6 +507,49 @@ 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
 // ---------------------------------------------------------------------------
@@ -486,8 +586,10 @@ router.put('/:id/targets', requireEncounterAccess, async (req, res, next) => {
      return res.status(400).json({ error: 'The combatant on turn cannot be their own target' });
    }

-    const found = await prisma.encounterParticipant.count({ where: { id: { in: participantIds }, encounterId: req.encounter.id } });
-    if (found !== participantIds.length) return res.status(400).json({ error: 'Combatant not found in this encounter' });
+    // 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);
@@ -500,21 +602,22 @@ router.put('/:id/targets', requireEncounterAccess, async (req, res, next) => {
 // 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 } } : {}),
      },
@@ -527,7 +630,7 @@ 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: {
@@ -535,7 +638,7 @@ router.post('/:id/advance-round', requireEncounterAccess, requireDM, async (req,
        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);
@@ -680,4 +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 ${money(total, ware.currency)}.`);
+    }
+
+    emitCharacterUpdated(req, character.id);
+    await respondWithEncounter(req, res, 201);
+  })
+);
+
 module.exports = router;
@@ -6,10 +6,14 @@
 // The coins, and what each is worth counted in copper: silver is 0.1 gold and
 // copper is 0.01 gold, so 1 gold = 10 silver = 100 copper and 1 silver = 10
 // copper. Whole numbers keep exchanges exact.
-const CURRENCIES = ['GOLD', 'SILVER', 'COPPER'];
+const COINS = ['GOLD', 'SILVER', 'COPPER'];
 const COIN_VALUE = { GOLD: 100, SILVER: 10, COPPER: 1 };
-// Each coin is its own column on the character.
-const COIN_COLUMN = { GOLD: 'gold', SILVER: 'silver', COPPER: 'copper' };
+// Everything a purse can hold: the coins, plus cash ($) — 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 {}

@@ -43,7 +47,7 @@ function planPayment(purse, currency, amount) {
  const delta = { GOLD: 0, SILVER: 0, COPPER: 0 };
  const left = (coin) => purse[coin] + delta[coin];
  let owed = amount * worth(currency);
-  if (CURRENCIES.reduce((sum, coin) => sum + purse[coin] * worth(coin), 0) < owed) return null;
+  if (COINS.reduce((sum, coin) => sum + purse[coin] * worth(coin), 0) < owed) return null;

  const pay = (coin, count) => {
    delta[coin] -= count;
@@ -51,13 +55,13 @@ function planPayment(purse, currency, amount) {
  };
  pay(currency, Math.min(purse[currency], amount));

-  const bigger = CURRENCIES.filter((coin) => worth(coin) > worth(currency)).reverse(); // nearest first
+  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 CURRENCIES.filter((c) => worth(c) < worth(coin))) {
+    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;
@@ -66,7 +70,7 @@ function planPayment(purse, currency, amount) {
    if (owed < 0) owed = 0;
  }

-  for (const coin of CURRENCIES.filter((c) => worth(c) < worth(currency))) {
+  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))));
  }
@@ -76,14 +80,16 @@ function planPayment(purse, currency, amount) {
 // 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.
+// 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 = CURRENCIES.filter((coin) => delta[coin] !== 0).sort((a, b) => (b === currency) - (a === currency));
+  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 = [];
@@ -103,9 +109,9 @@ async function spendCoins(db, { characterId, amount, currency = 'GOLD', reason,
  return rows;
 }

-// A purse's whole worth as one figure in gold, for messages: 265 copper-worth -> 2.65.
+// A purse's coins as one figure in gold, for messages: 265 copper-worth -> 2.65.
 function worthInGold(character) {
-  const copper = CURRENCIES.reduce((sum, coin) => sum + character[COIN_COLUMN[coin]] * COIN_VALUE[coin], 0);
+  const copper = COINS.reduce((sum, coin) => sum + character[COIN_COLUMN[coin]] * COIN_VALUE[coin], 0);
  return copper / COIN_VALUE.GOLD;
 }

@@ -127,4 +133,4 @@ async function giveGear(db, kind, { characterId, entry, quantity = 1, level, equ
  });
 }

-module.exports = { CURRENCIES, COIN_VALUE, COIN_COLUMN, InsufficientGoldError, adjustGold, planPayment, spendCoins, worthInGold, giveGear };
+module.exports = { CURRENCIES, COINS, COIN_VALUE, COIN_COLUMN, InsufficientGoldError, adjustGold, planPayment, spendCoins, worthInGold, giveGear };
@@ -334,7 +334,7 @@ HP bar, on their encounter card, in the quick stats and in the party lists.
 |---|---|---|
 | 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 | Only the DM's **Revive at 1 HP** |
+| 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.
@@ -359,7 +359,10 @@ The app does not roll it.
 - **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.
+  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
@@ -578,7 +581,22 @@ behind it.
 - The log is the only way a balance changes. Entries cannot be edited or
  deleted; to correct a mistake, record the opposite entry.
 - Starting gold (a campaign setting) is gold only. Encounter rewards and gifts
-  between characters can be in any coin.
+  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

@@ -740,6 +758,7 @@ Another Campaign" card on its sheet.
 | 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 |
@@ -776,7 +795,7 @@ calculations for them.
 - 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

@@ -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 | 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.
@@ -111,7 +113,7 @@ 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 +133,10 @@ 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.

@@ -149,8 +155,7 @@ 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 monster or NPC 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
@@ -173,12 +178,54 @@ the card is the same one as on the sheet, and both change the same character.
  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**.
+  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 or advances by itself: the app does not prompt for a save when
-the turn comes round, and a dying, stable or dead character keeps its place
-in the order.
+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

@@ -201,6 +248,14 @@ 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

@@ -212,7 +267,8 @@ healed) right now. One target is an ordinary attack; more than one is an
  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.
+  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.
@@ -276,7 +332,7 @@ 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 |

@@ -287,9 +343,9 @@ 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
@@ -300,7 +356,48 @@ 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 |
 |---|---|---|
@@ -309,13 +406,16 @@ 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 |
 |---|---|---|
@@ -329,22 +429,29 @@ information cannot be dug out of the page.
 | 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, revive the dead | Yes | No |
+| 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)
 - Applying an attack's damage automatically
 - 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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

@@ -1,7 +1,7 @@
 {
  "name": "frontend",
  "private": true,
-  "version": "1.7.2",
+  "version": "1.10.0",
  "type": "module",
  "scripts": {
    "dev": "vite",
@@ -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,
@@ -18,6 +18,7 @@ import type {
  Monster,
  Note,
  Npc,
+  SaleOffer,
  QuickStats,
  Spell,
  Weapon,
@@ -463,9 +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] }),
@@ -536,6 +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({
@@ -760,6 +778,19 @@ export function useSetTargets(encounterId: string) {
  });
 }

+// 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({
@@ -829,6 +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
 // --------------------------------------------------------------------------
@@ -108,7 +108,9 @@ export interface CampaignMemberSummary {
 }

 // The coins a character carries. 1 gold = 10 silver = 100 copper.
-export type Currency = 'GOLD' | 'SILVER' | '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
@@ -135,10 +137,11 @@ export interface CharacterSummary {
  currentHp: number;
  tempHp: number;
  deathSaves: DeathSaves;
-  // The purse; all three are null for another player's character.
+  // 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;
@@ -215,6 +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 {
@@ -302,6 +306,7 @@ export interface CharacterDetail {
  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;
@@ -339,6 +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;
@@ -346,6 +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.
@@ -402,6 +429,7 @@ export interface CharacterCombatInfo {
  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;
@@ -433,6 +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.
@@ -460,8 +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 {
@@ -497,6 +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[];
 }

@@ -32,7 +32,7 @@ function Pips({ kind, count, onSet }: { kind: 'success' | 'failure'; count: numb

 // 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 are the DM's alone.
+// tallies by hand and raising the dead from here are the DM's alone.
 export function DeathSaves({
  characterId,
  name,
@@ -78,7 +78,7 @@ export function DeathSaves({
          </>
        )}
        {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.' : 'Only the DM can bring them back.'}</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 && (
@@ -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>
+  );
+}
@@ -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>
+  );
+}
@@ -828,6 +828,11 @@ table.data-table tbody tr:hover {
  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;
@@ -1,4 +1,4 @@
-import type { Currency } from '../api/types';
+import type { Coin, Currency } from '../api/types';

 export const SPECIES_LABELS: Record<string, string> = {
  HUMAN: 'Human',
@@ -73,25 +73,34 @@ export function hpBarClass(current: number, max: number): string {
 }

 // Coins. Silver is worth 0.1 gold and copper 0.01 gold.
-export const CURRENCIES: Currency[] = ['GOLD', 'SILVER', 'COPPER'];
-export const COIN_LABELS: Record<Currency, string> = { GOLD: 'Gold', SILVER: 'Silver', COPPER: 'Copper' };
-export const COIN_SHORT: Record<Currency, string> = { GOLD: 'gp', SILVER: 'sp', COPPER: 'cp' };
-export const COIN_FIELD: Record<Currency, 'gold' | 'silver' | 'copper'> = { GOLD: 'gold', SILVER: 'silver', COPPER: 'copper' };
+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<Currency, number> = { GOLD: 100, SILVER: 10, COPPER: 1 };
+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' };

-type Purse = { gold: number | null; silver: number | null; copper: number | null };
+// "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]}`;
+}

-// "12 gp · 5 sp · 3 cp". Gold always shows; silver and copper only when held.
+type Purse = { gold: number | null; silver: number | null; copper: number | null; cash: number | null };
+
+// "12 gp · 5 sp · 3 cp · $40". Gold always shows; the rest only when held.
 export function formatPurse(purse: Purse): string {
  return CURRENCIES.filter((c) => c === 'GOLD' || (purse[COIN_FIELD[c]] ?? 0) > 0)
-    .map((c) => `${purse[COIN_FIELD[c]] ?? 0} ${COIN_SHORT[c]}`)
+    .map((c) => formatMoney(purse[COIN_FIELD[c]] ?? 0, c))
    .join(' · ');
 }

-// The whole purse as one figure in gold, e.g. 12.65.
+// 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 = CURRENCIES.reduce((sum, c) => sum + (purse[COIN_FIELD[c]] ?? 0) * COIN_VALUE[c], 0);
+  const copper = COINS.reduce((sum, c) => sum + (purse[COIN_FIELD[c]] ?? 0) * COIN_VALUE[c], 0);
  return copper / COIN_VALUE.GOLD;
 }

@@ -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`;
+}
@@ -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,
@@ -43,10 +44,11 @@ import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
 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.
@@ -236,6 +238,214 @@ 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,
@@ -304,6 +514,7 @@ 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);
@@ -333,6 +544,7 @@ 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('');
@@ -341,6 +553,7 @@ 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);
@@ -353,6 +566,7 @@ 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);
@@ -793,7 +1007,8 @@ 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
@@ -844,21 +1059,39 @@ 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>
@@ -1129,6 +1362,7 @@ 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();
                }}
@@ -1149,6 +1383,10 @@ 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>
            )}
@@ -1159,6 +1397,7 @@ 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>
@@ -1174,6 +1413,14 @@ export function CampaignHomePage() {
                      <td>
                        <SpellDamageSelect spellName={s.name} value={s.damageDice} onChange={(damageDice) => patchSpell.mutate({ id: s.id, damageDice })} />
                      </td>
+                      <td>
+                        <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 })}
@@ -1194,8 +1441,14 @@ export function CampaignHomePage() {
                <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>
@@ -1205,62 +1458,93 @@ 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>
+                        <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>{m.challengeRating || '—'}</td>
                      <td>{m.ac}</td>
                      <td>{m.maxHp}</td>
+                      <td>{m.speed}</td>
+                      <td>{fmtMod(m.attackBonus)}</td>
+                      <td>{m.damageDice || '—'}</td>
                      <td>
-                        <button className="btn btn-ghost" onClick={() => deleteMonster.mutate(m.id)}>✕</button>
+                        <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"
+                          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>
                  ))}
@@ -40,15 +40,16 @@ import { usePagination, Pagination } from '../components/Paginated';
 import {
  ABILITY_LABELS,
  CLASS_LABELS,
+  COINS,
  COIN_FIELD,
  COIN_LABELS,
-  COIN_SHORT,
  COIN_VALUE,
  CURRENCIES,
  SKILL_LABELS,
  SPECIES_LABELS,
  fmtMod,
  extractErrorMessage,
+  formatMoney,
  formatPurse,
  purseWorthInGold,
  spellLevelLabel,
@@ -56,7 +57,7 @@ import {
 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, Currency } 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
@@ -112,10 +113,10 @@ function GiveCard({ character, onError }: { character: CharacterDetail; onError:
  const heldWeapon = character.weapons.find((w) => w.weaponId === id);
  const heldItem = character.inventoryItems.find((i) => i.itemId === id);
  // 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.
+  // 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 = CURRENCIES.reduce((sum, c) => sum + held(c) * COIN_VALUE[c], 0);
-  const affordable = (c: Currency) => Math.floor(purseInCopper / COIN_VALUE[c]);
+  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));
@@ -170,7 +171,7 @@ function GiveCard({ character, onError }: { character: CharacterDetail; onError:
            <option value="">What to give…</option>
            {coinsHeld.map((c) => (
              <option key={c} value={`gold:${c}`}>
-                {COIN_LABELS[c]} ({held(c)} {COIN_SHORT[c]} held)
+                {COIN_LABELS[c]} ({formatMoney(held(c), c)} held)
              </option>
            ))}
            {character.weapons.length > 0 && (
@@ -267,8 +268,8 @@ export function CharacterSheetPage() {
  const [goldReason, setGoldReason] = useState('');
  const [goldCurrency, setGoldCurrency] = useState<Currency>('GOLD');
  const [exchangeAmount, setExchangeAmount] = useState('');
-  const [exchangeFrom, setExchangeFrom] = useState<Currency>('GOLD');
-  const [exchangeTo, setExchangeTo] = useState<Currency>('SILVER');
+  const [exchangeFrom, setExchangeFrom] = useState<Coin>('GOLD');
+  const [exchangeTo, setExchangeTo] = useState<Coin>('SILVER');
  const [noteBody, setNoteBody] = useState('');
  const [pickedWeaponId, setPickedWeaponId] = useState('');
  const [pickedSpellId, setPickedSpellId] = useState('');
@@ -828,7 +829,8 @@ export function CharacterSheetPage() {
        </div>
        <p className="subtitle" style={{ marginTop: 0 }}>
          1 gold = 10 silver = 100 copper. Worth {purseWorthInGold(character)} gold in all. Spending and giving make
-          change for you: if you are short of a coin, a bigger one is broken.
+          change for you: if you are short of a coin, a bigger one is broken. Cash ($) is kept apart: it is never
+          exchanged for coins.
        </p>
        {canEdit && (
          <div className="flex-row flex-wrap">
@@ -876,16 +878,16 @@ export function CharacterSheetPage() {
              onChange={(e) => setExchangeAmount(e.target.value)}
              style={{ width: 100 }}
            />
-            <select aria-label="Exchange from" value={exchangeFrom} onChange={(e) => setExchangeFrom(e.target.value as Currency)}>
-              {CURRENCIES.map((c) => (
+            <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 Currency)}>
-              {CURRENCIES.map((c) => (
+            <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>
@@ -902,7 +904,8 @@ export function CharacterSheetPage() {
            <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)}`} {COIN_SHORT[t.currency ?? 'GOLD']}
+                  {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)' }}>
@@ -911,7 +914,7 @@ export function CharacterSheetPage() {
                </div>
              </div>
              <span className="mono" style={{ color: 'var(--text-muted)' }}>
-                {t.balanceAfter} {COIN_SHORT[t.currency ?? 'GOLD']}
+                {formatMoney(t.balanceAfter, t.currency ?? 'GOLD')}
              </span>
            </div>
          ))}
@@ -15,6 +15,7 @@ import {
  useAdvanceRound,
  useNextTurn,
  useSetTargets,
+  useReviveParticipant,
  usePatchEncounter,
  useSetEncounterArchived,
  useDeleteEncounter,
@@ -29,7 +30,8 @@ import { Spinner, ErrorBanner } from '../components/Spinner';
 import { NumberInput } from '../components/NumberInput';
 import { HpBar } from '../components/HpBar';
 import { DeathSaves } from '../components/DeathSaves';
-import { ABILITY_LABELS, CLASS_LABELS, COIN_LABELS, CURRENCIES, SPECIES_LABELS, extractErrorMessage, fmtMod, spellLevelLabel } from '../lib/format';
+import { TradePanel } from '../components/TradePanel';
+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,
@@ -188,6 +190,11 @@ function CombatantCard({
            )}
            {npc && <span className={`badge badge-${npc.disposition.toLowerCase()}`}>{npc.disposition}</span>}
            {isDown && !info && <span className="badge badge-hostile">Down</span>}
+            {p.hidden && (
+              <span className="badge" title="Out of the fight. Players no longer see this card, and it has no turn.">
+                Hidden from players
+              </span>
+            )}
            {onTarget && (
              <button
                className={`btn btn-target${isTargeted ? ' is-on' : ''}`}
@@ -600,7 +607,7 @@ function AttackBar({
 }

 function rewardLabel(r: EncounterReward): string {
-  if (r.type === 'GOLD') return `${r.gold} ${COIN_LABELS[r.currency ?? 'GOLD'].toLowerCase()}`;
+  if (r.type === 'GOLD') return formatMoney(r.gold ?? 0, r.currency ?? 'GOLD', true);
  const entry = r.type === 'WEAPON' ? r.weapon : r.item;
  return `${entry?.name ?? 'Removed from the pool'}${r.quantity > 1 ? ` ×${r.quantity}` : ''} · Lv ${r.level}`;
 }
@@ -844,6 +851,7 @@ export function EncounterPage() {
  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 ?? '');
@@ -853,25 +861,39 @@ 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));
@@ -906,15 +928,26 @@ export function EncounterPage() {
    />
  );

+  // 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>
@@ -1047,7 +1080,41 @@ export function EncounterPage() {
              onClear={() => setTargets.mutate([], fail)}
            />
          )}
-          {participants.length === 0 && (
+          {!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.'
@@ -1115,6 +1182,16 @@ 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}
@@ -1,19 +1,19 @@
 {
  "name": "dnd-campaign-manager",
-  "version": "1.7.2",
+  "version": "1.10.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "dnd-campaign-manager",
-      "version": "1.7.2",
+      "version": "1.10.0",
      "workspaces": [
        "backend",
        "frontend"
      ]
    },
    "backend": {
-      "version": "1.7.2",
+      "version": "1.10.0",
      "dependencies": {
        "@prisma/client": "^5.20.0",
        "bcrypt": "^5.1.1",
@@ -31,7 +31,7 @@
      }
    },
    "frontend": {
-      "version": "1.7.2",
+      "version": "1.10.0",
      "dependencies": {
        "@tanstack/react-query": "^5.103.2",
        "axios": "^1.20.0",
@@ -1,6 +1,6 @@
 {
  "name": "dnd-campaign-manager",
-  "version": "1.7.2",
+  "version": "1.10.0",
  "private": true,
  "description": "D&D 5e campaign manager — monorepo root",
  "workspaces": [
Author	SHA1	Message	Date
joshuaandClaude Opus 5.5	c852ecb2e4	V1.10.0: NPCs change money and sell things - An NPC can change gold and cash at a rate of their own ("2 gold = $15"), the same both ways. Only gold and cash are taken: no silver, no copper and no change, and the amount has to be a whole multiple of the rate. - An NPC can sell weapons and items from the campaign pools, each with a price in any coin or in cash, a level and an optional stock. The wares follow the NPC into every quest. An encounter can sell things itself too, for a stall with nobody behind it. - Trading is open only in an NPC quest in progress, never in a battle, with an NPC who is in the scene and standing, for a character who is in it. Players see every rate and ware and trade for their own character in a new Trade card; the DM can trade for anyone. - Only the DM sets trade up: "Trade" on an NPC's row on the campaign page, and the DM's part of the Trade card for an encounter's own wares. A ware's price and stock can be edited afterwards. - Every exchange and purchase is written to the character's money log. - All packages at version 1.10.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-07 13:45:40 +02:00
joshuaandClaude Opus 5.5	bdce3399ee	V1.9.0: full monster stat blocks, and cash ($) - "+ Add Monster" takes the whole stat block: challenge rating, speed, the six ability scores, special trait and notes, as well as name, AC, HP, attack and damage. Damage can name its type ("1d6+2 necrotic"). - Monsters can be edited: "Edit" on a row opens the same form filled in. Copies already in encounters show the new stat block. - The monster list shows each full stat block, the library picker shows speed and ability scores too, and removing a monster asks first. - Characters have a fourth balance, cash ($), for crossover worlds. It is gained, spent, given and awarded like a coin, but it has no worth in coins: it is never exchanged or used to make change. - `npm test` in the backend runs again (the script pointed at a jest path that does not exist in the workspace). - All packages at version 1.9.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-07 13:15:55 +02:00
joshuaandClaude Opus 5.5	f764878960	V1.8.1: combatants who have had their turn move to "Next Round" - In a battle in progress, whoever is on turn is at the top of the list with those still to act beneath them. Each combatant whose turn has passed drops to a "Next Round" section at the bottom, and a new round puts everyone back. - All packages at version 1.8.1. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-06 14:49:44 +02:00
joshuaandClaude Opus 5.5	6b466d497e	V1.8.0: the fallen are hidden, and allies can revive the dead - A dead character, or a monster or NPC at 0 HP, is out of the fight: the server no longer sends it to players, target marks included, and it has no turn. Healing or reviving brings it straight back. - The DM's screen leaves the fallen out too until "Show dead" is ticked, which lists them in a group of their own, marked hidden. - Players see dead characters by name in a Fallen box. The player whose character is on turn in a battle gets "Try revive" there if that character is on their feet and knows a spell that revives, at a level they can cast. The dead come back at 1 HP. - Spells have a "Revives" tick in the campaign's spell list. Revivify and Raise Dead have it, in the library and in existing campaigns. - A dead character cannot be added to an encounter until revived. - All packages at version 1.8.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-06 14:25:46 +02:00