diff --git a/src/main/java/game/single/service/SingleGameServiceImpl.java b/src/main/java/game/single/service/SingleGameServiceImpl.java
index 0b78fa9..c8c4b99 100644
--- a/src/main/java/game/single/service/SingleGameServiceImpl.java
+++ b/src/main/java/game/single/service/SingleGameServiceImpl.java
@@ -49,7 +49,11 @@ public SingleGameServiceImpl(String roomId, ScheduledExecutorService scheduler)
 	
 	@Override
 	public synchronized void onOpen(Session session, String userId) throws Exception {
+		System.out.println("[SingleGame] onOpen - roomId=" + roomId + " userId=" + userId
+			+ " currentPlayers=" + players.size() + " sessionId=" + session.getId());
+
 		if (players.size() >= 2) {
+			System.out.println("[SingleGame] REJECT - 이미 2명이 접속중입니다.");
 	        session.close();
 	        return;
 	    }
@@ -58,7 +62,7 @@ public synchronized void onOpen(Session session, String userId) throws Exception
 	    players.add(session);
 	    sessionToUserId.put(session, userId);
 
-	    System.out.println("접속: " + session.getId());
+	    System.out.println("[SingleGame] 접속 완료: " + session.getId() + " (현재 " + players.size() + "명)");
 
 	    // 2) 아직 2명 안 찼으면 WAIT 브로드캐스트
 	    if (players.size() < 2) {
@@ -96,9 +100,14 @@ public synchronized void onOpen(Session session, String userId) throws Exception
 
 	@Override
 	public synchronized void onMessage(String msg, Session session) throws Exception {
-		if (gameOver.get())
+		System.out.println("[SingleGame] onMessage - msg=" + msg + " sessionId=" + session.getId()
+			+ " gameOver=" + gameOver.get() + " turn=" + turn.get() + " players.size=" + players.size());
+
+		if (gameOver.get()) {
+			System.out.println("[SingleGame] 게임이 이미 종료됨 - 메시지 무시");
 			return;
-		
+		}
+
 		JsonObject json = gson.fromJson(msg, JsonObject.class);
 
 		if (msg.contains("SINGLE_GIVEUP")) {
@@ -125,8 +134,17 @@ public synchronized void onMessage(String msg, Session session) throws Exception
 			return;
 		}
 
-		if (players.get(turn.get()) != session)
+		int currentTurnIdx = turn.get();
+		Session currentTurnSession = (currentTurnIdx < players.size()) ? players.get(currentTurnIdx) : null;
+		System.out.println("[SingleGame] 턴 체크 - currentTurnIdx=" + currentTurnIdx
+			+ " currentTurnSession=" + (currentTurnSession != null ? currentTurnSession.getId() : "null")
+			+ " requestSession=" + session.getId()
+			+ " isSame=" + (currentTurnSession == session));
+
+		if (players.get(turn.get()) != session) {
+			System.out.println("[SingleGame] 턴이 아닌 플레이어의 요청 - 무시");
 			return;
+		}
 		
 		if (!json.has("x") || !json.has("y")) {
 			return;
@@ -182,11 +200,15 @@ public synchronized void onMessage(String msg, Session session) throws Exception
 
 	@Override
 	public synchronized void onClose(Session session) {
+		System.out.println("[SingleGame] onClose - sessionId=" + session.getId()
+			+ " currentPlayers=" + players.size());
+
 		players.remove(session);
 		sessionToUserId.remove(session);
 
 	    // 남은 사람이 없으면 게임 리셋(혹은 게임 종료 처리)
 	    if (players.isEmpty()) {
+			System.out.println("[SingleGame] 모든 플레이어 나감 - 게임 리셋");
 	        board = new int[15][15];
 	        turn.set(0);
 	        gameOver.set(false);
@@ -194,7 +216,7 @@ public synchronized void onClose(Session session) {
 	        wpass = 0;
 	        if (turnTask != null) turnTask.cancel(false);
 	    }
-	    System.out.println("연결 종료: " + session.getId());
+	    System.out.println("[SingleGame] 연결 종료 완료: " + session.getId() + " (남은 플레이어: " + players.size() + "명)");
 	}
 
 	private synchronized void startTurnTimer() {
diff --git a/src/main/java/room/service/RoomService.java b/src/main/java/room/service/RoomService.java
index e1e663c..7f341bf 100644
--- a/src/main/java/room/service/RoomService.java
+++ b/src/main/java/room/service/RoomService.java
@@ -10,6 +10,7 @@ public class RoomService {
 
 	private static final String STATUS_IN_ROOM = "0";
 	private static final String STATUS_EXIT = "2";
+	private static final String DELETED_ROOM_ID = "00000000-0000-0000-0000-000000000000";
 
 	/**
 	 * @return 결과 상태
@@ -72,6 +73,12 @@ SELECT COUNT(*) AS cnt
 			  AND host_user_id = ?
 			""";
 
+		final String qUpdateGameResultRoomId = """
+			UPDATE game_result
+			SET room_id = ?
+			WHERE room_id = ?
+			""";
+
 		final String qDeleteRoomPlayers = """
 			DELETE FROM room_player
 			WHERE room_id = ?
@@ -87,14 +94,21 @@ SELECT COUNT(*) AS cnt
 
 			try {
 				// 방 row 잠금
+				boolean roomExists = false;
 				try (PreparedStatement pstmt = conn.prepareStatement(qLockRoom)) {
 					pstmt.setString(1, roomId);
 					try (ResultSet rs = pstmt.executeQuery()) {
-						if (!rs.next())
-							throw new IllegalArgumentException("room not found: " + roomId);
+						roomExists = rs.next();
 					}
 				}
 
+				// 방이 이미 삭제되었으면 조용히 종료 (정상 처리)
+				if (!roomExists) {
+					System.out.println("[RoomService] 방이 이미 삭제됨 - roomId=" + roomId);
+					conn.commit();
+					return "ROOM_DELETE";
+				}
+
 				// 퇴장 처리 (IN_ROOM -> EXIT)
 				int updated;
 				try (PreparedStatement pstmt = conn.prepareStatement(qExitPlayer)) {
@@ -105,8 +119,11 @@ SELECT COUNT(*) AS cnt
 					updated = pstmt.executeUpdate();
 				}
 
+				System.out.println("[RoomService] 퇴장 처리 - roomId=" + roomId + " userId=" + userId + " updated=" + updated);
+
 				// 이미 나가있거나 없는 유저면 아무 것도 안 함
 				if (updated == 0) {
+					System.out.println("[RoomService] 이미 나간 유저 - 종료");
 					conn.commit();
 					return "ROOM_EXIT";
 				}
@@ -128,18 +145,32 @@ SELECT COUNT(*) AS cnt
 					}
 				}
 
+				System.out.println("[RoomService] 남은 인원 - roomId=" + roomId + " activeCnt=" + activeCnt);
+
 				// 방에 아무도 없으면 방 삭제
 				if (activeCnt == 0) {
+					// 1) game_result의 room_id를 특수 값으로 변경 (외래 키 제약 조건 회피)
+					try (PreparedStatement pstmt = conn.prepareStatement(qUpdateGameResultRoomId)) {
+						pstmt.setString(1, DELETED_ROOM_ID);
+						pstmt.setString(2, roomId);
+						int gameResultUpdated = pstmt.executeUpdate();
+						System.out.println("[RoomService] game_result의 room_id 업데이트: " + gameResultUpdated + "건");
+					}
+
+					// 2) room_player 삭제
 					try (PreparedStatement pstmt = conn.prepareStatement(qDeleteRoomPlayers)) {
 						pstmt.setString(1, roomId);
 						pstmt.executeUpdate();
 					}
+
+					// 3) room 삭제
 					try (PreparedStatement pstmt = conn.prepareStatement(qDeleteRoom)) {
 						pstmt.setString(1, roomId);
 						pstmt.executeUpdate();
 					}
 
 					conn.commit();
+					System.out.println("[RoomService] 방 삭제 완료: " + roomId);
 					return "ROOM_DELETE";
 				}
 
diff --git a/src/main/resources/db/migration/V7__alter_gameresult.sql b/src/main/resources/db/migration/V7__alter_gameresult.sql
new file mode 100644
index 0000000..b3b1b0d
--- /dev/null
+++ b/src/main/resources/db/migration/V7__alter_gameresult.sql
@@ -0,0 +1,2 @@
+ALTER TABLE game_result
+DROP CONSTRAINT FK_GAME_RESULT_ROOM;
\ No newline at end of file
diff --git a/src/main/resources/db/migration/V8__insert_room.sql b/src/main/resources/db/migration/V8__insert_room.sql
new file mode 100644
index 0000000..0d1a991
--- /dev/null
+++ b/src/main/resources/db/migration/V8__insert_room.sql
@@ -0,0 +1,4 @@
+DELETE
+FROM room
+WHERE id = '00000000-0000-0000-0000-000000000000';
+COMMIT;
\ No newline at end of file