src/rules/dungeon.ts

@@ -49,7 +49,15 @@ function cloneRoom(room: RoomState): RoomState {
     dimensions: { ...room.dimensions },
     exits: room.exits.map((exit) => ({ ...exit })),
     discovery: { ...room.discovery },
-    encounter: room.encounter ? { ...room.encounter, creatureIds: [...room.encounter.creatureIds] } : undefined,
+    encounter: room.encounter
+      ? {
+          ...room.encounter,
+          creatureIds: [...room.encounter.creatureIds],
+          creatureNames: room.encounter.creatureNames
+            ? [...room.encounter.creatureNames]
+            : undefined,
+        }
+      : undefined,
     objects: room.objects.map((object) => ({
       ...object,
       effects: object.effects ? [...object.effects] : undefined,

src/rules/encounters.test.ts

@@ -0,0 +1,73 @@
+import { describe, expect, it } from "vitest";
+
+import { sampleContentPack } from "@/data/sampleContentPack";
+
+import { createRoomStateFromTemplate } from "./rooms";
+import { resolveRoomEncounter } from "./encounters";
+
+function createSequenceRoller(values: number[]) {
+  let index = 0;
+
+  return () => {
+    const next = values[index];
+    index += 1;
+    return next;
+  };
+}
+
+describe("encounter resolution", () => {
+  it("marks explicitly empty rooms as having no encounter", () => {
+    const room = createRoomStateFromTemplate(
+      sampleContentPack,
+      "room.level1.small.empty",
+      1,
+      "room.level1.small.empty-space",
+    );
+    room.notes.push("Nothing here.");
+
+    const result = resolveRoomEncounter(sampleContentPack, room);
+
+    expect(result.encounter?.creatureIds).toEqual([]);
+    expect(result.encounter?.resultLabel).toBe("No encounter");
+  });
+
+  it("uses room context to resolve a guard encounter table", () => {
+    const room = createRoomStateFromTemplate(
+      sampleContentPack,
+      "room.level1.guard-room",
+      1,
+      "room.level1.normal.guard-room",
+    );
+    room.notes.push("Use the guards encounter table if occupied.");
+
+    const result = resolveRoomEncounter(
+      sampleContentPack,
+      room,
+      createSequenceRoller([6]),
+    );
+
+    expect(result.lookup?.entry.label).toBe("Guard and Warrior");
+    expect(result.encounter?.sourceTableCode).toBe("L1G");
+    expect(result.encounter?.creatureNames).toEqual(["Guard", "Warrior"]);
+  });
+
+  it("resolves crate events from room context when the room hints at crate rolls", () => {
+    const room = createRoomStateFromTemplate(
+      sampleContentPack,
+      "room.level1.storage-area",
+      1,
+      "room.level1.normal.storage-area",
+    );
+    room.notes.push("Roll for food, drink, or crate events while searching.");
+
+    const result = resolveRoomEncounter(
+      sampleContentPack,
+      room,
+      createSequenceRoller([2]),
+    );
+
+    expect(result.lookup?.entry.label).toBe("Giant Rat Pair");
+    expect(result.encounter?.sourceTableCode).toBe("L1CE");
+    expect(result.encounter?.creatureNames).toEqual(["Giant Rat Pair"]);
+  });
+});

src/rules/encounters.ts

@@ -0,0 +1,110 @@
+import { findTableByCode } from "@/data/contentHelpers";
+import type { ContentPack } from "@/types/content";
+import type { EncounterState, RoomState } from "@/types/state";
+
+import { lookupTable, type TableLookupResult } from "./tables";
+import type { DiceRoller } from "./dice";
+
+export type EncounterResolutionResult = {
+  room: RoomState;
+  encounter?: EncounterState;
+  lookup?: TableLookupResult;
+};
+
+const ROOM_HINT_TO_TABLE: Array<{ pattern: RegExp; tableCode: string }> = [
+  { pattern: /\bdogs?\b/i, tableCode: "L1D" },
+  { pattern: /\bguards?\b/i, tableCode: "L1G" },
+  { pattern: /\bmartial\b/i, tableCode: "L1M" },
+  { pattern: /\bworkers?\b/i, tableCode: "L1W" },
+  { pattern: /\blabourers?\b/i, tableCode: "L1P" },
+  { pattern: /\bpreacher\b/i, tableCode: "L1P" },
+  { pattern: /\banimals?\b/i, tableCode: "L1A" },
+  { pattern: /\bsnakes?\b/i, tableCode: "L1A" },
+  { pattern: /\bfungal\b/i, tableCode: "L1F" },
+  { pattern: /\bslimy\b/i, tableCode: "L1F" },
+  { pattern: /\bcrate\b/i, tableCode: "L1CE" },
+];
+
+function splitEncounterLabel(label: string) {
+  return label
+    .split(/\sand\s/i)
+    .map((part) => part.trim())
+    .filter(Boolean);
+}
+
+function inferEncounterTableCode(room: RoomState) {
+  const noteText = room.notes.join(" ");
+  const flagText = room.flags.join(" ");
+  const combinedText = `${noteText} ${flagText}`;
+
+  for (const mapping of ROOM_HINT_TO_TABLE) {
+    if (mapping.pattern.test(combinedText)) {
+      return mapping.tableCode;
+    }
+  }
+
+  return undefined;
+}
+
+function isNonEncounterRoom(room: RoomState) {
+  const noteText = room.notes.join(" ").toLowerCase();
+  return noteText.includes("nothing here") || noteText.includes("no encounter");
+}
+
+export function resolveRoomEncounter(
+  content: ContentPack,
+  room: RoomState,
+  roller?: DiceRoller,
+): EncounterResolutionResult {
+  if (room.encounter?.resolved) {
+    return {
+      room,
+      encounter: room.encounter,
+    };
+  }
+
+  if (isNonEncounterRoom(room)) {
+    const emptyEncounter: EncounterState = {
+      id: `${room.id}.encounter`,
+      creatureIds: [],
+      creatureNames: [],
+      resultLabel: "No encounter",
+      resolved: true,
+    };
+
+    return {
+      room: {
+        ...room,
+        encounter: emptyEncounter,
+      },
+      encounter: emptyEncounter,
+    };
+  }
+
+  const tableCode = inferEncounterTableCode(room);
+
+  if (!tableCode) {
+    return { room };
+  }
+
+  const table = findTableByCode(content, tableCode);
+  const lookup = lookupTable(table, { roller });
+  const creatureNames = splitEncounterLabel(lookup.entry.label);
+  const encounter: EncounterState = {
+    id: `${room.id}.encounter`,
+    sourceTableCode: tableCode,
+    creatureIds: creatureNames.map((_, index) => `${room.id}.creature.${index + 1}`),
+    creatureNames,
+    resultLabel: lookup.entry.label,
+    resolved: true,
+  };
+
+  return {
+    room: {
+      ...room,
+      encounter,
+    },
+    encounter,
+    lookup,
+  };
+}

src/schemas/state.ts

@@ -110,6 +110,8 @@ export const encounterStateSchema = z.object({
   id: z.string().min(1),
   sourceTableCode: z.string().optional(),
   creatureIds: z.array(z.string()),
+  creatureNames: z.array(z.string()).optional(),
+  resultLabel: z.string().optional(),
   resolved: z.boolean(),
   surprise: z.boolean().optional(),
   rewardPending: z.boolean().optional(),

src/types/state.ts

@@ -111,6 +111,8 @@ export type EncounterState = {
   id: string;
   sourceTableCode?: string;
   creatureIds: string[];
+  creatureNames?: string[];
+  resultLabel?: string;
   resolved: boolean;
   surprise?: boolean;
   rewardPending?: boolean;