diff --git a/examples/three-monks/rules.ts b/examples/three-monks/rules.ts
index 781d2d4..9489fdb 100644
--- a/examples/three-monks/rules.ts
+++ b/examples/three-monks/rules.ts
@@ -1,5 +1,6 @@
 import type { Entity, World } from "../../src/index";
 import { query } from "../../src/query";
+import type { ToolEffectRecorder } from "./stats";
 import {
   ActionCard,
   CARRYING_TOOLS,
@@ -82,20 +83,20 @@ export function collectProposals(world: World): RoundProposals {
   return proposals;
 }
 
-export function resolveRound(world: World): void {
+export function resolveRound(world: World, stats?: ToolEffectRecorder): void {
   const state = world.getSingleton(GameState);
   if (state.phase === "gameOver") return;
 
   state.phase = "resolving";
   const proposals = collectProposals(world);
 
-  if (proposals.chant) resolveChant(world);
-  if (proposals.fetchWater) resolveFetchWater(world);
-  if (proposals.exchange) resolveExchange(world);
-  if (proposals.drink) resolveDrink(world);
+  if (proposals.chant) resolveChant(world, stats);
+  if (proposals.fetchWater) resolveFetchWater(world, stats);
+  if (proposals.exchange) resolveExchange(world, stats);
+  if (proposals.drink) resolveDrink(world, stats);
   if (world.getSingleton(GameState).phase === "gameOver") return;
 
-  resolveEndOfRoundTools(world);
+  resolveEndOfRoundTools(world, stats);
   checkWinner(world);
 }
 
@@ -118,7 +119,10 @@ export function prepareNextRound(world: World): void {
   state.message = `Round ${world.getSingleton(Table).round}: choose an action card.`;
 }
 
-export function resolveFetchWater(world: World): void {
+export function resolveFetchWater(
+  world: World,
+  stats?: ToolEffectRecorder,
+): void {
   const table = world.getSingleton(Table);
   const players = getPlayersInSeatOrder(world);
   const participants = players.filter((player) => {
@@ -141,6 +145,12 @@ export function resolveFetchWater(world: World): void {
     if (playerData.water >= placed) {
       playerData.water -= placed;
       tool.water += placed;
+      stats?.record(tool.kind, "挑水", {
+        playerWaterDelta: -placed,
+        ownToolWaterDelta: placed,
+      });
+    } else {
+      stats?.record(tool.kind, "挑水", {}, "水不足，未放水");
     }
   }
 
@@ -151,11 +161,18 @@ export function resolveFetchWater(world: World): void {
     if (tool.kind === "ladle" && table.centralWater > 0) {
       table.centralWater--;
       tool.water++;
+      stats?.record(tool.kind, "挑水", {
+        ownToolWaterDelta: 1,
+        centralWaterDelta: -1,
+      });
     }
   }
 }
 
-export function resolveExchange(world: World): void {
+export function resolveExchange(
+  world: World,
+  stats?: ToolEffectRecorder,
+): void {
   const participants = getPlayersInSeatOrder(world).filter(
     (player) => getSelectedAction(world, player) !== "chant",
   );
@@ -167,8 +184,13 @@ export function resolveExchange(world: World): void {
   for (const toolEntity of tools) {
     const tool = world.get(toolEntity, Tool);
     if (tool.kind === "shoulderPole" && tool.water > 0) {
-      table.centralWater += tool.water;
+      const dumped = tool.water;
+      table.centralWater += dumped;
       tool.water = 0;
+      stats?.record(tool.kind, "交换", {
+        ownToolWaterDelta: -dumped,
+        centralWaterDelta: dumped,
+      });
     }
   }
 
@@ -179,7 +201,7 @@ export function resolveExchange(world: World): void {
   }
 }
 
-export function resolveDrink(world: World): void {
+export function resolveDrink(world: World, stats?: ToolEffectRecorder): void {
   for (const player of getPlayersFromMarker(world)) {
     if (!canParticipateInDrink(world, player)) continue;
 
@@ -199,10 +221,17 @@ export function resolveDrink(world: World): void {
       tool.water -= maxFromTool;
       playerData.water += maxFromTool;
       drankFromTool = maxFromTool;
+      stats?.record(tool.kind, "喝水", {
+        playerWaterDelta: maxFromTool,
+        ownToolWaterDelta: -maxFromTool,
+      });
     }
 
     if (tool.kind === "waterJar") {
       playerData.water++;
+      stats?.record(tool.kind, "喝水", {
+        playerWaterDelta: 1,
+      });
     }
 
     if (
@@ -212,6 +241,10 @@ export function resolveDrink(world: World): void {
     ) {
       table.centralWater--;
       tool.water++;
+      stats?.record(tool.kind, "喝水", {
+        ownToolWaterDelta: 1,
+        centralWaterDelta: -1,
+      });
     }
 
     if (playerData.water >= 10) {
@@ -221,7 +254,7 @@ export function resolveDrink(world: World): void {
   }
 }
 
-export function resolveChant(world: World): void {
+export function resolveChant(world: World, stats?: ToolEffectRecorder): void {
   const chanters = getPlayersFromMarker(world).filter(
     (player) => getSelectedAction(world, player) === "chant",
   );
@@ -235,17 +268,32 @@ export function resolveChant(world: World): void {
 
     if (tool.kind === "bottle") {
       tool.water++;
+      stats?.record(tool.kind, "念经", {
+        ownToolWaterDelta: 1,
+      });
     } else if (tool.kind === "mouse") {
-      moveOneNeighborWaterTo(world, player, toolEntity);
+      const moved = moveOneNeighborWaterTo(world, player, toolEntity);
+      if (moved) {
+        stats?.record(tool.kind, "念经", {
+          ownToolWaterDelta: 1,
+          otherToolWaterDelta: -1,
+        });
+      } else {
+        stats?.record(tool.kind, "念经", {}, "相邻道具无水可偷");
+      }
     }
   }
 }
 
-export function resolveEndOfRoundTools(world: World): void {
+export function resolveEndOfRoundTools(
+  world: World,
+  stats?: ToolEffectRecorder,
+): void {
   for (const toolEntity of world.query(query(Tool))) {
     const tool = world.get(toolEntity, Tool);
     if (tool.kind === "woodenFish") {
       world.getSingleton(WoodenFishMarker).holder = tool.owner;
+      stats?.record(tool.kind, "轮末", {}, "获得木鱼标记");
       return;
     }
   }
@@ -271,7 +319,7 @@ function moveOneNeighborWaterTo(
   world: World,
   player: Entity,
   destinationTool: Entity,
-): void {
+): boolean {
   const neighbors = [
     getLeftPlayer(world, player),
     getRightPlayer(world, player),
@@ -282,9 +330,10 @@ function moveOneNeighborWaterTo(
     if (neighborTool.water > 0) {
       neighborTool.water--;
       world.get(destinationTool, Tool).water++;
-      return;
+      return true;
     }
   }
+  return false;
 }
 
 function setWinner(world: World, player: Entity): void {
diff --git a/examples/three-monks/simulate.ts b/examples/three-monks/simulate.ts
index 555a420..e21543b 100644
--- a/examples/three-monks/simulate.ts
+++ b/examples/three-monks/simulate.ts
@@ -8,6 +8,7 @@ import {
   getPlayersInSeatOrder,
   type ActionKind,
 } from "./components";
+import { ToolEffectStats, formatToolEffectSummaries } from "./stats";
 import {
   beginSelectionPhase,
   checkWinner,
@@ -52,7 +53,7 @@ interface GameStats {
   waterDiff: number;
 }
 
-function runSingleGame(seed: number): GameStats {
+function runSingleGame(seed: number, stats?: ToolEffectStats): GameStats {
   const random = mulberry32(seed);
   const world = new World();
   const playerNames = ["慧空", "明心", "了尘", "净远"];
@@ -76,13 +77,13 @@ function runSingleGame(seed: number): GameStats {
 
     const proposals = collectProposals(world);
 
-    if (proposals.chant) resolveChant(world);
-    if (proposals.fetchWater) resolveFetchWater(world);
-    if (proposals.exchange) resolveExchange(world);
-    if (proposals.drink) resolveDrink(world);
+    if (proposals.chant) resolveChant(world, stats);
+    if (proposals.fetchWater) resolveFetchWater(world, stats);
+    if (proposals.exchange) resolveExchange(world, stats);
+    if (proposals.drink) resolveDrink(world, stats);
     if (world.getSingleton(GameState).phase === "gameOver") break;
 
-    resolveEndOfRoundTools(world);
+    resolveEndOfRoundTools(world, stats);
     checkWinner(world);
     if (world.getSingleton(GameState).phase === "gameOver") break;
 
@@ -104,12 +105,13 @@ function runSingleGame(seed: number): GameStats {
 export function runSimulation(gameCount = 100, startSeed = 20260701): void {
   let totalRounds = 0;
   let totalWaterDiff = 0;
+  const toolStats = new ToolEffectStats();
 
   console.log(`开始模拟 ${gameCount} 局游戏...`);
 
   for (let i = 0; i < gameCount; i++) {
     const seed = startSeed + i;
-    const stats = runSingleGame(seed);
+    const stats = runSingleGame(seed, toolStats);
     totalRounds += stats.rounds;
     totalWaterDiff += stats.waterDiff;
   }
@@ -122,6 +124,10 @@ export function runSimulation(gameCount = 100, startSeed = 20260701): void {
   console.log(`结束时平均轮数: ${avgRounds.toFixed(2)} 轮`);
   console.log(`结束时首尾玩家平均水差距: ${avgWaterDiff.toFixed(2)} 口水`);
   console.log("==========================================");
+  console.log("\n道具效果统计（总变化量）:");
+  for (const line of formatToolEffectSummaries(toolStats)) {
+    console.log(line);
+  }
 }
 
 if (process.argv[1]?.endsWith("simulate.ts")) {
diff --git a/examples/three-monks/stats.ts b/examples/three-monks/stats.ts
new file mode 100644
index 0000000..f7a45f6
--- /dev/null
+++ b/examples/three-monks/stats.ts
@@ -0,0 +1,94 @@
+import type { ToolKind } from "./components";
+import { TOOL_LABELS } from "./logging";
+
+export interface ToolEffectDelta {
+  playerWaterDelta?: number;
+  ownToolWaterDelta?: number;
+  otherToolWaterDelta?: number;
+  centralWaterDelta?: number;
+}
+
+export interface ToolEffectRecord extends Required<ToolEffectDelta> {
+  tool: ToolKind;
+  phase: string;
+  description?: string;
+}
+
+export interface ToolEffectSummary extends Required<ToolEffectDelta> {
+  tool: ToolKind;
+  activations: number;
+}
+
+export interface ToolEffectRecorder {
+  record(tool: ToolKind, phase: string, delta?: ToolEffectDelta, description?: string): void;
+}
+
+export class ToolEffectStats implements ToolEffectRecorder {
+  private readonly summaries = new Map<ToolKind, ToolEffectSummary>();
+  private readonly records: ToolEffectRecord[] = [];
+
+  record(
+    tool: ToolKind,
+    phase: string,
+    delta: ToolEffectDelta = {},
+    description?: string,
+  ): void {
+    const record: ToolEffectRecord = {
+      tool,
+      phase,
+      description,
+      playerWaterDelta: delta.playerWaterDelta ?? 0,
+      ownToolWaterDelta: delta.ownToolWaterDelta ?? 0,
+      otherToolWaterDelta: delta.otherToolWaterDelta ?? 0,
+      centralWaterDelta: delta.centralWaterDelta ?? 0,
+    };
+
+    this.records.push(record);
+
+    const summary = this.summaries.get(tool) ?? {
+      tool,
+      activations: 0,
+      playerWaterDelta: 0,
+      ownToolWaterDelta: 0,
+      otherToolWaterDelta: 0,
+      centralWaterDelta: 0,
+    };
+
+    summary.activations++;
+    summary.playerWaterDelta += record.playerWaterDelta;
+    summary.ownToolWaterDelta += record.ownToolWaterDelta;
+    summary.otherToolWaterDelta += record.otherToolWaterDelta;
+    summary.centralWaterDelta += record.centralWaterDelta;
+    this.summaries.set(tool, summary);
+  }
+
+  getRecords(): readonly ToolEffectRecord[] {
+    return this.records;
+  }
+
+  getSummaries(): ToolEffectSummary[] {
+    return [...this.summaries.values()].sort((a, b) =>
+      TOOL_LABELS[a.tool].localeCompare(TOOL_LABELS[b.tool], "zh-Hans-CN"),
+    );
+  }
+}
+
+export function formatToolEffectSummaries(stats: ToolEffectStats): string[] {
+  const summaries = stats.getSummaries();
+  if (summaries.length === 0) return ["无道具效果记录"];
+
+  return [
+    "道具 | 触发次数 | 玩家水变化 | 自身道具水变化 | 其他道具水变化 | 中央水变化",
+    "--- | ---: | ---: | ---: | ---: | ---:",
+    ...summaries.map((summary) =>
+      [
+        TOOL_LABELS[summary.tool],
+        summary.activations,
+        summary.playerWaterDelta,
+        summary.ownToolWaterDelta,
+        summary.otherToolWaterDelta,
+        summary.centralWaterDelta,
+      ].join(" | "),
+    ),
+  ];
+}