diff --git a/apps/client/src/scenes/game/GameManager.ts b/apps/client/src/scenes/game/GameManager.ts
index 87ff08e..3eaa308 100644
--- a/apps/client/src/scenes/game/GameManager.ts
+++ b/apps/client/src/scenes/game/GameManager.ts
@@ -4,11 +4,11 @@
  * マップ，ネットワーク同期，ゲームループを統合する
  */
 import { Application, Container, Ticker } from "pixi.js";
+import { createBombIdFromPayload } from "@repo/shared";
+import type { BombNetworkPayload } from "@repo/shared";
 import { socketManager } from "@client/network/SocketManager";
 import { GameMapController } from "./entities/map/GameMapController";
 import { BombManager } from "./entities/bomb/BombManager";
-import { createBombIdFromPayload } from "./entities/bomb/BombManager";
-import type { BombUpsertPayload } from "./entities/bomb/BombManager";
 import { GameTimer } from "./application/GameTimer";
 import { GameNetworkSync } from "./application/GameNetworkSync";
 import { GameLoop } from "./application/GameLoop";
@@ -47,8 +47,8 @@
     return placed.bombId;
   }
 
-  public upsertBomb(bombId: string, payload: BombUpsertPayload): void {
-    this.bombManager?.upsertBomb(bombId, payload);
+  public upsertBombFromNetwork(bombId: string, payload: BombNetworkPayload): void {
+    this.bombManager?.upsertBombFromNetwork(bombId, payload);
   }
 
   public removeBomb(bombId: string): void {
@@ -103,7 +103,7 @@
       onGameEnd: this.lockInput.bind(this),
       onBombPlaced: (payload) => {
         const bombId = createBombIdFromPayload(payload);
-        this.upsertBomb(bombId, payload);
+        this.upsertBombFromNetwork(bombId, payload);
       },
     });
     this.networkSync.bind();
diff --git a/apps/client/src/scenes/game/entities/bomb/BombManager.ts b/apps/client/src/scenes/game/entities/bomb/BombManager.ts
index 7691fb2..dfd69fb 100644
--- a/apps/client/src/scenes/game/entities/bomb/BombManager.ts
+++ b/apps/client/src/scenes/game/entities/bomb/BombManager.ts
@@ -5,7 +5,8 @@
  */
 import type { Container } from "pixi.js";
 import { config } from "@client/config";
-import type { BombPlacedPayload } from "@repo/shared";
+import { createBombIdFromPayload } from "@repo/shared";
+import type { BombNetworkPayload } from "@repo/shared";
 import { LocalPlayerController } from "@client/scenes/game/entities/player/PlayerController";
 import { BombController } from "./BombController";
 import type { GamePlayers } from "@client/scenes/game/application/game.types";
@@ -13,20 +14,15 @@
 /** 経過時間ミリ秒を返す関数型 */
 export type ElapsedMsProvider = () => number;
 
-/** 爆弾の追加更新に使う入力データ型 */
-export type BombUpsertPayload = BombPlacedPayload & {
-  radiusGrid?: number;
+/** 爆弾の描画更新に使う入力データ型 */
+export type BombRenderPayload = BombNetworkPayload & {
+  radiusGrid: number;
 };
 
 /** 爆弾設置時に返す結果型 */
 export type BombPlacementResult = {
   bombId: string;
-  payload: BombPlacedPayload;
-};
-
-/** 爆弾ペイロードから一意キーを生成する */
-export const createBombIdFromPayload = (payload: BombPlacedPayload): string => {
-  return `${payload.x}:${payload.y}:${payload.explodeAtElapsedMs}`;
+  payload: BombNetworkPayload;
 };
 
 type BombManagerOptions = {
@@ -64,14 +60,14 @@
     }
 
     const position = me.getPosition();
-    const payload: BombPlacedPayload = {
+    const payload: BombNetworkPayload = {
       x: position.x,
       y: position.y,
       explodeAtElapsedMs: elapsedMs + BOMB_FUSE_MS,
     };
     const bombId = createBombIdFromPayload(payload);
 
-    this.upsertBomb(bombId, payload);
+    this.upsertBombFromNetwork(bombId, payload);
     this.lastBombPlacedElapsedMs = elapsedMs;
     return {
       bombId,
@@ -79,20 +75,25 @@
     };
   }
 
-  /** 指定IDの爆弾を追加または更新する */
-  public upsertBomb(bombId: string, payload: BombUpsertPayload): void {
+  /** 通信ペイロードから指定IDの爆弾を追加または更新する */
+  public upsertBombFromNetwork(bombId: string, payload: BombNetworkPayload): void {
+    const renderPayload: BombRenderPayload = {
+      ...payload,
+      radiusGrid: config.GAME_CONFIG.BOMB_RADIUS_GRID,
+    };
+
+    this.upsertBomb(bombId, renderPayload);
+  }
+
+  /** 描画ペイロードで指定IDの爆弾を追加または更新する */
+  public upsertBomb(bombId: string, payload: BombRenderPayload): void {
     const current = this.bombs.get(bombId);
     if (current) {
       this.worldContainer.removeChild(current.getDisplayObject());
       current.destroy();
     }
 
-    const resolvedPayload = {
-      ...payload,
-      radiusGrid: payload.radiusGrid ?? config.GAME_CONFIG.BOMB_RADIUS_GRID,
-    };
-
-    const bomb = new BombController(resolvedPayload);
+    const bomb = new BombController(payload);
     this.bombs.set(bombId, bomb);
     this.worldContainer.addChild(bomb.getDisplayObject());
   }
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index 67972ff..f25e374 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -31,6 +31,7 @@
 	ServerToClientPayloadOf,
 	CurrentPlayersPayload,
 	BombPlacedPayload,
+	BombNetworkPayload,
 	GameStartPayload,
 	GameResultPayload,
 	GameResultRanking,
@@ -44,6 +45,8 @@
 } from "./protocol/events";
 /** ソケットイベントブリッジ生成関数を再公開 */
 export { createSocketEventBridge } from "./protocol/socketEventBridge";
+/** 爆弾ペイロードから同期用IDを生成するユーティリティを再公開 */
+export { createBombIdFromPayload } from "./protocol/events";
 /** ソケットイベントブリッジ生成に必要な最小インターフェースを再公開 */
 export type { SocketBridgeTarget } from "./protocol/socketEventBridge";
 /** 共有設定値を再公開 */
diff --git a/packages/shared/src/protocol/bombIdentity.ts b/packages/shared/src/protocol/bombIdentity.ts
new file mode 100644
index 0000000..ac2dcb0
--- /dev/null
+++ b/packages/shared/src/protocol/bombIdentity.ts
@@ -0,0 +1,14 @@
+/**
+ * bombIdentity
+ * 爆弾通信ペイロードの識別キー生成を提供する
+ * クライアントとサーバーで同一規約のID生成を共有する
+ */
+import type { BombPlacedPayload } from "./eventPayloads";
+
+/** 通信で扱う爆弾基本ペイロード型 */
+export type BombNetworkPayload = BombPlacedPayload;
+
+/** 爆弾ペイロードから同期用IDを生成する */
+export const createBombIdFromPayload = (payload: BombNetworkPayload): string => {
+  return `${payload.x}:${payload.y}:${payload.explodeAtElapsedMs}`;
+};
diff --git a/packages/shared/src/protocol/events.ts b/packages/shared/src/protocol/events.ts
index 4415c64..bdd0978 100644
--- a/packages/shared/src/protocol/events.ts
+++ b/packages/shared/src/protocol/events.ts
@@ -7,6 +7,12 @@
 /** ソケットイベント名定数を再公開する */
 export { SocketEvents } from "./socketEvents";
 
+/** 爆弾同期識別子の生成ユーティリティを再公開する */
+export { createBombIdFromPayload } from "./bombIdentity";
+
+/** 爆弾通信ペイロード型を再公開する */
+export type { BombNetworkPayload } from "./bombIdentity";
+
 /** 基本ペイロード型を再公開する */
 export type {
   UpdatePlayersPayload,