diff --git a/apps/client/src/network/handlers/GameHandler.ts b/apps/client/src/network/handlers/GameHandler.ts
index 783f994..b337cd4 100644
--- a/apps/client/src/network/handlers/GameHandler.ts
+++ b/apps/client/src/network/handlers/GameHandler.ts
@@ -6,8 +6,10 @@
 import type { Socket } from "socket.io-client";
 import { protocol } from "@repo/shared";
 import type {
-  playerTypes,
   CurrentPlayersPayload,
+  GameStartPayload,
+  NewPlayerPayload,
+  RemovePlayerPayload,
   UpdateMapCellsPayload,
   UpdatePlayersPayload,
 } from "@repo/shared";
@@ -16,16 +18,16 @@
 export type GameHandler = {
   onCurrentPlayers: (callback: (players: CurrentPlayersPayload) => void) => void;
   offCurrentPlayers: (callback: (players: CurrentPlayersPayload) => void) => void;
-  onNewPlayer: (callback: (player: playerTypes.PlayerData) => void) => void;
-  offNewPlayer: (callback: (player: playerTypes.PlayerData) => void) => void;
+  onNewPlayer: (callback: (player: NewPlayerPayload) => void) => void;
+  offNewPlayer: (callback: (player: NewPlayerPayload) => void) => void;
   onUpdatePlayers: (callback: (players: UpdatePlayersPayload) => void) => void;
   offUpdatePlayers: (callback: (players: UpdatePlayersPayload) => void) => void;
-  onRemovePlayer: (callback: (id: string) => void) => void;
-  offRemovePlayer: (callback: (id: string) => void) => void;
+  onRemovePlayer: (callback: (id: RemovePlayerPayload) => void) => void;
+  offRemovePlayer: (callback: (id: RemovePlayerPayload) => void) => void;
   onUpdateMapCells: (callback: (updates: UpdateMapCellsPayload) => void) => void;
   offUpdateMapCells: (callback: (updates: UpdateMapCellsPayload) => void) => void;
-  onGameStart: (callback: (data: { startTime: number }) => void) => void;
-  offGameStart: (callback: (data: { startTime: number }) => void) => void;
+  onGameStart: (callback: (data: GameStartPayload) => void) => void;
+  offGameStart: (callback: (data: GameStartPayload) => void) => void;
   sendMove: (x: number, y: number) => void;
   readyForGame: () => void;
 };
@@ -70,7 +72,7 @@
       socket.off(protocol.SocketEvents.GAME_START, callback);
     },
     sendMove: (x, y) => {
-      const payload: playerTypes.MovePayload = { x, y };
+      const payload = { x, y };
       socket.emit(protocol.SocketEvents.MOVE, payload);
     },
     readyForGame: () => {
diff --git a/apps/client/src/scenes/game/application/GameNetworkSync.ts b/apps/client/src/scenes/game/application/GameNetworkSync.ts
index 6a0e349..9a8a245 100644
--- a/apps/client/src/scenes/game/application/GameNetworkSync.ts
+++ b/apps/client/src/scenes/game/application/GameNetworkSync.ts
@@ -4,7 +4,14 @@
  * プレイヤー生成更新削除とマップ更新購読を管理する
  */
 import { Container } from "pixi.js";
-import type { playerTypes, CurrentPlayersPayload, UpdateMapCellsPayload } from "@repo/shared";
+import type {
+  CurrentPlayersPayload,
+  GameStartPayload,
+  NewPlayerPayload,
+  RemovePlayerPayload,
+  UpdateMapCellsPayload,
+  UpdatePlayersPayload,
+} from "@repo/shared";
 import { socketManager } from "@client/network/SocketManager";
 import { LocalPlayerController, RemotePlayerController } from "@client/scenes/game/entities/player/PlayerController";
 import { GameMapController } from "@client/scenes/game/entities/map/GameMapController";
@@ -35,20 +42,20 @@
     });
   };
 
-  private handleNewPlayer = (p: playerTypes.PlayerData) => {
+  private handleNewPlayer = (p: NewPlayerPayload) => {
     const playerController = new RemotePlayerController(p);
     this.worldContainer.addChild(playerController.getDisplayObject());
     this.players[p.id] = playerController;
   };
 
-  private handleGameStart = (data: { startTime: number }) => {
+  private handleGameStart = (data: GameStartPayload) => {
     if (data && data.startTime) {
       this.onGameStart(data.startTime);
       console.log(`[GameManager] ゲーム開始時刻同期完了: ${data.startTime}`);
     }
   };
 
-  private handlePlayerUpdates = (changedPlayers: playerTypes.PlayerData[]) => {
+  private handlePlayerUpdates = (changedPlayers: UpdatePlayersPayload) => {
     // UPDATE_PLAYERS は差分のみ届くため，対象IDだけ上書き更新する
     changedPlayers.forEach((playerData) => {
       if (playerData.id === this.myId) return;
@@ -60,7 +67,7 @@
     });
   };
 
-  private handleRemovePlayer = (id: string) => {
+  private handleRemovePlayer = (id: RemovePlayerPayload) => {
     const target = this.players[id];
     if (target) {
       this.worldContainer.removeChild(target.getDisplayObject());
diff --git a/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts b/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
index 6708616..fdb544f 100644
--- a/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
+++ b/apps/server/src/domains/game/application/ports/gameUseCasePorts.ts
@@ -7,6 +7,8 @@
   playerTypes,
   roomTypes,
   CurrentPlayersPayload,
+  GameStartPayload,
+  RemovePlayerPayload,
   UpdateMapCellsPayload,
   UpdatePlayersPayload,
 } from "@repo/shared";
@@ -62,8 +64,8 @@
     cellUpdates: UpdateMapCellsPayload
   ): void;
   publishGameEndToRoom(roomId: roomTypes.Room["roomId"]): void;
-  publishGameStartToRoom(roomId: roomTypes.Room["roomId"], payload: { startTime: number }): void;
+  publishGameStartToRoom(roomId: roomTypes.Room["roomId"], payload: GameStartPayload): void;
   publishCurrentPlayersToSocket(players: CurrentPlayersPayload): void;
-  publishGameStartToSocket(payload: { startTime: number }): void;
-  publishPlayerRemovedToRoom(roomId: roomTypes.Room["roomId"], removedPlayerId: string): void;
+  publishGameStartToSocket(payload: GameStartPayload): void;
+  publishPlayerRemovedToRoom(roomId: roomTypes.Room["roomId"], removedPlayerId: RemovePlayerPayload): void;
 }
diff --git a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
index d152965..4d92e41 100644
--- a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
+++ b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
@@ -5,9 +5,10 @@
 import { Server } from "socket.io";
 import { protocol } from "@repo/shared";
 import type {
-  playerTypes,
+  GameStartPayload,
   roomTypes,
   CurrentPlayersPayload,
+  RemovePlayerPayload,
   UpdateMapCellsPayload,
   UpdatePlayersPayload,
 } from "@repo/shared";
@@ -16,9 +17,7 @@
 import type { CommonHandlerContext } from "../CommonHandler";
 
 type RoomId = roomTypes.Room["roomId"];
-type SocketId = playerTypes.PlayerData["id"];
 type PongPayload = { clientTime: number; serverTime: number };
-type GameStartPayload = { startTime: number };
 
 /** ゲーム出力アダプターのインターフェース */
 export type GameOutputAdapter = Omit<GameOutputPort, "publishPlayerRemovedToRoom">;
@@ -58,7 +57,7 @@
   const emitToRoom = createEmitToRoom(io);
 
   return {
-    publishPlayerRemovedToRoom: (roomId: RoomId, removedPlayerId: SocketId) => {
+    publishPlayerRemovedToRoom: (roomId: RoomId, removedPlayerId: RemovePlayerPayload) => {
       emitToRoom(roomId, protocol.SocketEvents.REMOVE_PLAYER, removedPlayerId);
     },
   };
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index 4f3646a..6141266 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -10,6 +10,9 @@
 export * as protocol from "./protocol/events";
 export type {
 	CurrentPlayersPayload,
+	GameStartPayload,
+	NewPlayerPayload,
+	RemovePlayerPayload,
 	UpdateMapCellsPayload,
 	UpdatePlayersPayload,
 } from "./protocol/events";
diff --git a/packages/shared/src/protocol/events.ts b/packages/shared/src/protocol/events.ts
index d64eb18..99a17ff 100644
--- a/packages/shared/src/protocol/events.ts
+++ b/packages/shared/src/protocol/events.ts
@@ -4,6 +4,7 @@
  * クライアントとサーバー間のイベント契約を共有する
  */
 import type { TickData } from "../domains/game/game.type";
+import type { PlayerData } from "../domains/player/player.type";
 
 /** ソケットイベント名の一覧定数 */
 export const SocketEvents = {
@@ -42,3 +43,12 @@
 
 /** UPDATE_MAP_CELLS イベントで送受信するマップ差分配列 */
 export type UpdateMapCellsPayload = TickData["cellUpdates"];
+
+/** NEW_PLAYER イベントで送受信するプレイヤー情報 */
+export type NewPlayerPayload = PlayerData;
+
+/** REMOVE_PLAYER イベントで送受信するプレイヤーID */
+export type RemovePlayerPayload = PlayerData["id"];
+
+/** GAME_START イベントで送受信するゲーム開始情報 */
+export type GameStartPayload = { startTime: number };