diff --git a/apps/client/src/scenes/game/application/loopSteps/SimulationStep.ts b/apps/client/src/scenes/game/application/loopSteps/SimulationStep.ts
index 0f4759e..2aef873 100644
--- a/apps/client/src/scenes/game/application/loopSteps/SimulationStep.ts
+++ b/apps/client/src/scenes/game/application/loopSteps/SimulationStep.ts
@@ -63,7 +63,10 @@
       me.tick();
 
       const now = this.nowMsProvider();
-      if (now - this.lastPositionSentTime >= config.GAME_CONFIG.PLAYER_POSITION_UPDATE_MS) {
+      if (
+        now - this.lastPositionSentTime
+        >= config.GAME_CONFIG.NETWORK_SYNC.PLAYER_POSITION_UPDATE_MS
+      ) {
         const position = me.getPosition();
         this.moveSender.sendMove(position.x, position.y);
         this.lastPositionSentTime = now;
@@ -71,7 +74,7 @@
     } else if (this.wasMoving) {
       me.tick();
       const position = me.getPosition();
-      this.moveSender.sendMove(position.x, position.y);
+      this.moveSender.sendMove(position.x, position.y, { force: true });
     } else {
       me.tick();
     }
diff --git a/apps/client/src/scenes/game/application/network/PlayerMoveSender.ts b/apps/client/src/scenes/game/application/network/PlayerMoveSender.ts
index df0c394..64fee02 100644
--- a/apps/client/src/scenes/game/application/network/PlayerMoveSender.ts
+++ b/apps/client/src/scenes/game/application/network/PlayerMoveSender.ts
@@ -3,32 +3,33 @@
  * ローカルプレイヤー移動の送信責務を提供する
  * シミュレーション層から通信実装を分離する
  */
-import { config } from "@client/config";
+import { domain } from "@repo/shared";
 import { socketManager } from "@client/network/SocketManager";
 
+/** 移動送信時の動作オプション */
+export type SendMoveOptions = {
+  force?: boolean;
+};
+
 /** 移動送信のインターフェース型 */
 export type MoveSender = {
-  sendMove: (x: number, y: number) => void;
-};
-
-type QuantizedPosition = {
-  x: number;
-  y: number;
+  sendMove: (x: number, y: number, options?: SendMoveOptions) => void;
 };
 
 /** ソケット経由で移動送信を行う実装 */
 export class SocketPlayerMoveSender implements MoveSender {
-  private lastSentPosition: QuantizedPosition | null = null;
+  private lastSentPosition: domain.game.player.MovePayload | null = null;
 
   /** 指定座標をサーバーへ送信する */
-  public sendMove(x: number, y: number): void {
-    const quantizedPosition = this.quantizePosition(x, y);
+  public sendMove(x: number, y: number, options?: SendMoveOptions): void {
+    const quantizedPosition = domain.game.player.quantizeMovePayload({ x, y });
     const lastPosition = this.lastSentPosition;
 
     if (
+      !options?.force
+      &&
       lastPosition
-      && lastPosition.x === quantizedPosition.x
-      && lastPosition.y === quantizedPosition.y
+      && domain.game.player.isSameMovePayload(lastPosition, quantizedPosition)
     ) {
       return;
     }
@@ -36,20 +37,4 @@
     this.lastSentPosition = quantizedPosition;
     socketManager.game.sendMove(quantizedPosition.x, quantizedPosition.y);
   }
-
-  private quantizePosition(x: number, y: number): QuantizedPosition {
-    return {
-      x: this.quantizeAxis(x),
-      y: this.quantizeAxis(y),
-    };
-  }
-
-  private quantizeAxis(value: number): number {
-    if (!Number.isFinite(value)) {
-      return 0;
-    }
-
-    const scale = config.GAME_CONFIG.POSITION_QUANTIZE_SCALE;
-    return Math.round(value * scale) / scale;
-  }
 }
\ No newline at end of file
diff --git a/apps/server/src/domains/game/application/services/GameSessionLifecycleService.ts b/apps/server/src/domains/game/application/services/GameSessionLifecycleService.ts
index f6e826c..76ba85c 100644
--- a/apps/server/src/domains/game/application/services/GameSessionLifecycleService.ts
+++ b/apps/server/src/domains/game/application/services/GameSessionLifecycleService.ts
@@ -85,7 +85,7 @@
       return;
     }
 
-    const tickRate = config.GAME_CONFIG.PLAYER_POSITION_UPDATE_MS;
+    const tickRate = config.GAME_CONFIG.NETWORK_SYNC.PLAYER_POSITION_UPDATE_MS;
     const session = new GameRoomSession(
       this.roomId,
       playerIds,
diff --git a/apps/server/src/domains/game/application/useCases/startGameUseCase.ts b/apps/server/src/domains/game/application/useCases/startGameUseCase.ts
index ed6fa07..b0a9b7d 100644
--- a/apps/server/src/domains/game/application/useCases/startGameUseCase.ts
+++ b/apps/server/src/domains/game/application/useCases/startGameUseCase.ts
@@ -25,6 +25,34 @@
   output: StartGameOutputPort;
 };
 
+type TickUpdatePublishParams = {
+  roomId: string;
+  output: StartGameOutputPort;
+  tickData: Parameters<StartGamePort["startRoomSession"]>[2] extends {
+    onTick: (data: infer TTickData) => void;
+  }
+    ? TTickData
+    : never;
+};
+
+const publishTickUpdates = ({
+  roomId,
+  output,
+  tickData,
+}: TickUpdatePublishParams): void => {
+  if (tickData.playerUpdates.length > 0) {
+    output.publishUpdatePlayersToRoom(roomId, tickData.playerUpdates);
+  }
+
+  if (tickData.cellUpdates.length > 0) {
+    output.publishMapCellUpdatesToRoom(roomId, tickData.cellUpdates);
+  }
+
+  if (tickData.hurricaneUpdates.length > 0) {
+    output.publishUpdateHurricanesToRoom(roomId, tickData.hurricaneUpdates);
+  }
+};
+
 /** ゲームセッション開始とティック通知，終了通知を実行する */
 export const startGameUseCase = ({
   roomId,
@@ -50,17 +78,7 @@
 
   gameSession.startRoomSession(playerIds, playerNamesById, {
     onTick: (tickData) => {
-      if (tickData.playerUpdates.length > 0) {
-        output.publishUpdatePlayersToRoom(roomId, tickData.playerUpdates);
-      }
-
-      if (tickData.cellUpdates.length > 0) {
-        output.publishMapCellUpdatesToRoom(roomId, tickData.cellUpdates);
-      }
-
-      if (tickData.hurricaneUpdates.length > 0) {
-        output.publishUpdateHurricanesToRoom(roomId, tickData.hurricaneUpdates);
-      }
+      publishTickUpdates({ roomId, output, tickData });
     },
     onGameEnd: (resultPayload) => {
       logEvent(logScopes.GAME_USE_CASE, {
diff --git a/apps/server/src/network/adapters/gamePayloadSanitizers.ts b/apps/server/src/network/adapters/gamePayloadSanitizers.ts
index 35fffec..2c2ba1f 100644
--- a/apps/server/src/network/adapters/gamePayloadSanitizers.ts
+++ b/apps/server/src/network/adapters/gamePayloadSanitizers.ts
@@ -2,11 +2,19 @@
  * gamePayloadSanitizers
  * ゲーム関連の送信ペイロードを境界で正規化する
  */
+import { domain } from "@repo/shared";
 import type { UpdatePlayersPayload } from "@repo/shared";
 
 /** UPDATE_PLAYERS の送信値を座標差分のみへ正規化する */
 export const sanitizeUpdatePlayersPayload = (
   players: UpdatePlayersPayload
 ): UpdatePlayersPayload => {
-  return players.map(({ id, x, y }) => ({ id, x, y }));
+  return players.map(({ id, x, y }) => {
+    const quantized = domain.game.player.quantizeMovePayload({ x, y });
+    return {
+      id,
+      x: quantized.x,
+      y: quantized.y,
+    };
+  });
 };
diff --git a/apps/server/src/network/handlers/CommonHandler.ts b/apps/server/src/network/handlers/CommonHandler.ts
index 493e951..2636c34 100644
--- a/apps/server/src/network/handlers/CommonHandler.ts
+++ b/apps/server/src/network/handlers/CommonHandler.ts
@@ -12,27 +12,45 @@
   createEmitToSocketById,
 } from "@server/network/adapters/socketEmitters";
 
-/** ハンドラで共通利用する送信コンテキスト */
-export type CommonHandlerContext = {
+/** 到達保証を重視する送信関数群 */
+export type ReliableEmitters = {
   emitToAll: ReturnType<typeof createEmitToAll>;
   emitToRoom: ReturnType<typeof createEmitToRoom>;
-  emitToRoomVolatile: ReturnType<typeof createEmitToRoomVolatile>;
   emitToRoomExceptSocket: ReturnType<typeof createEmitToRoomExceptSocket>;
   emitToSocket: ReturnType<typeof createEmitToSocket>;
   emitToSocketById: ReturnType<typeof createEmitToSocketById>;
 };
 
+/** 鮮度を重視する高頻度送信関数群 */
+export type RealtimeEmitters = {
+  emitToRoom: ReturnType<typeof createEmitToRoomVolatile>;
+};
+
+/** ハンドラで共通利用する送信コンテキスト */
+export type CommonHandlerContext = {
+  reliable: ReliableEmitters;
+  realtime: RealtimeEmitters;
+};
+
 /** 送信先別のエミッタをまとめた共通コンテキストを生成する */
 export const createCommonHandlerContext = (
   io: Server,
   socket: Socket
 ): CommonHandlerContext => {
-  return {
+  const reliable: ReliableEmitters = {
     emitToAll: createEmitToAll(io),
     emitToRoom: createEmitToRoom(io),
-    emitToRoomVolatile: createEmitToRoomVolatile(io),
     emitToRoomExceptSocket: createEmitToRoomExceptSocket(io),
     emitToSocket: createEmitToSocket(socket),
     emitToSocketById: createEmitToSocketById(io),
   };
+
+  const realtime: RealtimeEmitters = {
+    emitToRoom: createEmitToRoomVolatile(io),
+  };
+
+  return {
+    reliable,
+    realtime,
+  };
 };
diff --git a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
index 0fb931b..3173cc0 100644
--- a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
+++ b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
@@ -48,16 +48,18 @@
 export const createGameOutputAdapter = (
   common: CommonHandlerContext,
 ): GameOutputAdapter => {
+  const { reliable, realtime } = common;
+
   return {
     publishPongToSocket: (payload: PongPayload) => {
-      common.emitToSocket(protocol.SocketEvents.PONG, payload);
+      reliable.emitToSocket(protocol.SocketEvents.PONG, payload);
     },
     publishUpdatePlayersToRoom: (
       roomId: RoomId,
       players: UpdatePlayersPayload,
     ) => {
       const sanitizedPlayers = sanitizeUpdatePlayersPayload(players);
-      common.emitToRoomVolatile(
+      realtime.emitToRoom(
         roomId,
         protocol.SocketEvents.UPDATE_PLAYERS,
         sanitizedPlayers,
@@ -68,7 +70,7 @@
       cellUpdates: domainNs.game.gridMap.CellUpdate[],
     ) => {
       const grouped = domainNs.game.gridMap.groupCellUpdates(cellUpdates);
-      common.emitToRoom(
+      reliable.emitToRoom(
         roomId,
         protocol.SocketEvents.UPDATE_MAP_CELLS,
         grouped,
@@ -78,26 +80,26 @@
       roomId: RoomId,
       hurricanes: UpdateHurricanesPayload,
     ) => {
-      common.emitToRoomVolatile(
+      realtime.emitToRoom(
         roomId,
         protocol.SocketEvents.UPDATE_HURRICANES,
         hurricanes,
       );
     },
     publishGameEndToRoom: (roomId: RoomId) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.GAME_END);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.GAME_END);
     },
     publishGameResultToRoom: (roomId: RoomId, payload: GameResultPayload) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.GAME_RESULT, payload);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.GAME_RESULT, payload);
     },
     publishGameStartToRoom: (roomId: RoomId, payload: GameStartPayload) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.GAME_START, payload);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.GAME_START, payload);
     },
     publishCurrentPlayersToSocket: (players: CurrentPlayersPayload) => {
-      common.emitToSocket(protocol.SocketEvents.CURRENT_PLAYERS, players);
+      reliable.emitToSocket(protocol.SocketEvents.CURRENT_PLAYERS, players);
     },
     publishGameStartToSocket: (payload: GameStartPayload) => {
-      common.emitToSocket(protocol.SocketEvents.GAME_START, payload);
+      reliable.emitToSocket(protocol.SocketEvents.GAME_START, payload);
     },
     publishBombPlacedToOthersInRoom: (
       roomId: RoomId,
@@ -105,11 +107,11 @@
       payload: BombPlacedPayload,
     ) => {
       if (isBotPlayerId(ownerSocketId)) {
-        common.emitToRoom(roomId, protocol.SocketEvents.BOMB_PLACED, payload);
+        reliable.emitToRoom(roomId, protocol.SocketEvents.BOMB_PLACED, payload);
         return;
       }
 
-      common.emitToRoomExceptSocket(
+      reliable.emitToRoomExceptSocket(
         roomId,
         ownerSocketId,
         protocol.SocketEvents.BOMB_PLACED,
@@ -120,7 +122,7 @@
       socketId: string,
       payload: BombPlacedAckPayload,
     ) => {
-      common.emitToSocketById(
+      reliable.emitToSocketById(
         socketId,
         protocol.SocketEvents.BOMB_PLACED_ACK,
         payload,
@@ -131,7 +133,7 @@
       deadPlayerId: string,
       payload: PlayerHitPayload,
     ) => {
-      common.emitToRoomExceptSocket(
+      reliable.emitToRoomExceptSocket(
         roomId,
         deadPlayerId,
         protocol.SocketEvents.PLAYER_HIT,
@@ -139,13 +141,13 @@
       );
     },
     publishPlayerHitToRoom: (roomId: RoomId, payload: PlayerHitPayload) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.PLAYER_HIT, payload);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.PLAYER_HIT, payload);
     },
     publishHurricaneHitToRoom: (
       roomId: RoomId,
       payload: HurricaneHitPayload,
     ) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.HURRICANE_HIT, payload);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.HURRICANE_HIT, payload);
     },
   };
 };
diff --git a/apps/server/src/network/handlers/game/gameEventOrchestrators.ts b/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
index bb6b4ae..faad83c 100644
--- a/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
+++ b/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
@@ -86,6 +86,7 @@
   deps: GameEventOrchestratorDeps,
   move: domain.game.player.MovePayload,
 ): void => {
+  const normalizedMove = domain.game.player.quantizeMovePayload(move);
   const resolved = runWithRuntimeByPlayerId(
     deps.roomManager,
     deps.runtimeRegistry,
@@ -94,7 +95,7 @@
       movePlayerUseCase({
         gameManager,
         playerId: deps.socketId,
-        move,
+        move: normalizedMove,
       });
     },
   );
diff --git a/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts b/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
index 090a0b9..daf7957 100644
--- a/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
+++ b/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
@@ -19,12 +19,14 @@
 export const createRoomOutputAdapter = (
   common: CommonHandlerContext
 ): RoomOutputAdapter => {
+  const { reliable } = common;
+
   return {
     publishRoomUpdateToRoom: (roomId: RoomId, room: RoomUpdatePayload) => {
-      common.emitToRoom(roomId, protocol.SocketEvents.ROOM_UPDATE, room);
+      reliable.emitToRoom(roomId, protocol.SocketEvents.ROOM_UPDATE, room);
     },
     publishJoinRejectedToSocket: (payload: domain.room.JoinRoomRejectedPayload) => {
-      common.emitToSocket(protocol.SocketEvents.ROOM_JOIN_REJECTED, payload);
+      reliable.emitToSocket(protocol.SocketEvents.ROOM_JOIN_REJECTED, payload);
     },
   };
 };
diff --git a/packages/shared/src/config/gameConfig.ts b/packages/shared/src/config/gameConfig.ts
index aaa29d8..b16fa5e 100644
--- a/packages/shared/src/config/gameConfig.ts
+++ b/packages/shared/src/config/gameConfig.ts
@@ -4,14 +4,21 @@
  * クライアントとサーバーで参照する定数群を提供する
  */
 /** ゲーム全体で利用する共有設定値 */
+const NETWORK_SYNC_CONFIG = {
+  PLAYER_POSITION_UPDATE_MS: 50,
+  POSITION_QUANTIZE_SCALE: 100,
+} as const;
+
+/** ゲーム全体で利用する共有設定値 */
 export const GAME_CONFIG = {
   // ゲーム進行設定（クライアント/サーバー契約）
   GAME_DURATION_SEC: 180, // 1ゲームの制限時間（秒）
   GAME_START_DELAY_MS: 5000, // 開始通知から実際にゲーム進行を開始するまでの待機時間（ms）
 
   // ネットワーク同期設定（クライアント/サーバー契約）
-  PLAYER_POSITION_UPDATE_MS: 50, // 座標送信間隔（20Hz）
-  POSITION_QUANTIZE_SCALE: 100, // 送信座標の量子化スケール（100なら小数第2位まで保持）
+  NETWORK_SYNC: NETWORK_SYNC_CONFIG,
+  PLAYER_POSITION_UPDATE_MS: NETWORK_SYNC_CONFIG.PLAYER_POSITION_UPDATE_MS, // 後方互換のため維持
+  POSITION_QUANTIZE_SCALE: NETWORK_SYNC_CONFIG.POSITION_QUANTIZE_SCALE, // 後方互換のため維持
 
   // グリッド（マス）設定（クライアント/サーバー契約）
   GRID_COLS: 40, // 横のマス数（グリッド単位）
diff --git a/packages/shared/src/domains/game/player/index.ts b/packages/shared/src/domains/game/player/index.ts
index d302a12..3dc0d4d 100644
--- a/packages/shared/src/domains/game/player/index.ts
+++ b/packages/shared/src/domains/game/player/index.ts
@@ -6,3 +6,9 @@
 
 /** プレイヤー契約関連の型を再公開する */
 export type { PlayerData, MovePayload } from "./player.type";
+/** MOVE ペイロード送信の正規化関数を再公開する */
+export {
+	DEFAULT_MOVE_QUANTIZE_SCALE,
+	quantizeMovePayload,
+	isSameMovePayload,
+} from "./moveSync";
diff --git a/packages/shared/src/domains/game/player/moveSync.ts b/packages/shared/src/domains/game/player/moveSync.ts
new file mode 100644
index 0000000..24f6c01
--- /dev/null
+++ b/packages/shared/src/domains/game/player/moveSync.ts
@@ -0,0 +1,41 @@
+/**
+ * moveSync
+ * MOVE ペイロードの送信正規化に関する関数を提供する
+ */
+import { GAME_CONFIG } from "../../../config/gameConfig";
+import type { MovePayload } from "./player.type";
+
+/** MOVE ペイロード量子化の既定スケール */
+export const DEFAULT_MOVE_QUANTIZE_SCALE =
+  GAME_CONFIG.NETWORK_SYNC.POSITION_QUANTIZE_SCALE;
+
+/** MOVE 座標を量子化して送信用の値へ正規化する */
+export const quantizeMovePayload = (
+  move: Readonly<MovePayload>,
+  scale = DEFAULT_MOVE_QUANTIZE_SCALE,
+): MovePayload => {
+  return {
+    x: quantizeMoveAxis(move.x, scale),
+    y: quantizeMoveAxis(move.y, scale),
+  };
+};
+
+/** MOVE ペイロードの値が一致するかを判定する */
+export const isSameMovePayload = (
+  left: Readonly<MovePayload>,
+  right: Readonly<MovePayload>,
+): boolean => {
+  return left.x === right.x && left.y === right.y;
+};
+
+const quantizeMoveAxis = (value: number, scale: number): number => {
+  if (!Number.isFinite(value)) {
+    return 0;
+  }
+
+  if (!Number.isFinite(scale) || scale <= 0) {
+    return value;
+  }
+
+  return Math.round(value * scale) / scale;
+};
\ No newline at end of file