diff --git a/.github/workflows/slack-notify-pr-open.yml b/.github/workflows/slack-notify-pr-open.yml
new file mode 100644
index 00000000..e992b56a
--- /dev/null
+++ b/.github/workflows/slack-notify-pr-open.yml
@@ -0,0 +1,22 @@
+name: slack-notify-pr-open
+
+on:
+  pull_request:
+    types: [opened, reopened]
+
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Send Slack notification
+        uses: rtCamp/action-slack-notify@v2
+        env:
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
+          SLACK_USERNAME: Github CI
+          SLACK_ICON: https://github.com/github.png
+          MSG_MINIMAL: ref,event
+          SLACK_COLOR: '#36a64f'
+          SLACK_TITLE: 'New Pull Request 🚀'
+          SLACK_MESSAGE: |
+            #${{ github.event.pull_request.number }} ${{ github.event.pull_request.title }}
+            🔗 ${{ github.event.pull_request.html_url }}
diff --git a/backend/build.gradle b/backend/build.gradle
index caf92a70..fda0ab52 100644
--- a/backend/build.gradle
+++ b/backend/build.gradle
@@ -42,6 +42,7 @@ dependencies {
 	testAnnotationProcessor 'org.projectlombok:lombok'
 	testRuntimeOnly 'com.h2database:h2'
 	testImplementation 'org.springframework.security:spring-security-test'
+	testImplementation 'com.github.database-rider:rider-spring:1.44.0'
 
 	/* ETC */
 	implementation 'org.apache.commons:commons-lang3:3.12.0'
diff --git a/backend/src/main/java/io/f1/backend/domain/admin/app/AdminDetailService.java b/backend/src/main/java/io/f1/backend/domain/admin/app/AdminDetailService.java
index 18bcedf8..989a6270 100644
--- a/backend/src/main/java/io/f1/backend/domain/admin/app/AdminDetailService.java
+++ b/backend/src/main/java/io/f1/backend/domain/admin/app/AdminDetailService.java
@@ -3,6 +3,7 @@
 import io.f1.backend.domain.admin.dao.AdminRepository;
 import io.f1.backend.domain.admin.dto.AdminPrincipal;
 import io.f1.backend.domain.admin.entity.Admin;
+import io.f1.backend.global.exception.errorcode.AdminErrorCode;
 
 import lombok.RequiredArgsConstructor;
 
@@ -23,7 +24,9 @@ public UserDetails loadUserByUsername(String username) throws UsernameNotFoundEx
                 adminRepository
                         .findByUsername(username)
                         .orElseThrow(
-                                () -> new UsernameNotFoundException("E404007: 존재하지 않는 관리자입니다."));
+                                () ->
+                                        new UsernameNotFoundException(
+                                                AdminErrorCode.ADMIN_NOT_FOUND.getMessage()));
         // 프론트엔드로 내려가지 않는 예외
         return new AdminPrincipal(admin);
     }
diff --git a/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginFailureHandler.java b/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginFailureHandler.java
index fe16eef5..74ee18d0 100644
--- a/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginFailureHandler.java
+++ b/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginFailureHandler.java
@@ -3,6 +3,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import io.f1.backend.domain.admin.dto.AdminLoginFailResponse;
+import io.f1.backend.global.exception.errorcode.AuthErrorCode;
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
@@ -31,7 +32,9 @@ public void onAuthenticationFailure(
         response.setContentType("application/json;charset=UTF-8");
 
         AdminLoginFailResponse errorResponse =
-                new AdminLoginFailResponse("E401005", "아이디 또는 비밀번호가 일치하지 않습니다.");
+                new AdminLoginFailResponse(
+                        AuthErrorCode.LOGIN_FAILED.getCode(),
+                        AuthErrorCode.LOGIN_FAILED.getMessage());
 
         response.getWriter().write(objectMapper.writeValueAsString(errorResponse));
     }
diff --git a/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginSuccessHandler.java b/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginSuccessHandler.java
index 7150d35a..8b786f8a 100644
--- a/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginSuccessHandler.java
+++ b/backend/src/main/java/io/f1/backend/domain/admin/app/handler/AdminLoginSuccessHandler.java
@@ -6,6 +6,8 @@
 import io.f1.backend.domain.admin.dao.AdminRepository;
 import io.f1.backend.domain.admin.dto.AdminPrincipal;
 import io.f1.backend.domain.admin.entity.Admin;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.AdminErrorCode;
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
@@ -36,7 +38,7 @@ public void onAuthenticationSuccess(
         Admin admin =
                 adminRepository
                         .findByUsername(principal.getUsername())
-                        .orElseThrow(() -> new RuntimeException("E404007: 존재하지 않는 관리자입니다."));
+                        .orElseThrow(() -> new CustomException(AdminErrorCode.ADMIN_NOT_FOUND));
 
         admin.updateLastLogin(LocalDateTime.now());
         adminRepository.save(admin);
diff --git a/backend/src/main/java/io/f1/backend/domain/game/app/GameService.java b/backend/src/main/java/io/f1/backend/domain/game/app/GameService.java
index 12cbd7ed..701b6b73 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/app/GameService.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/app/GameService.java
@@ -1,6 +1,8 @@
 package io.f1.backend.domain.game.app;
 
-import io.f1.backend.domain.game.dto.GameStartData;
+import static io.f1.backend.domain.quiz.mapper.QuizMapper.toGameStartResponse;
+
+import io.f1.backend.domain.game.dto.request.GameStartRequest;
 import io.f1.backend.domain.game.dto.response.GameStartResponse;
 import io.f1.backend.domain.game.event.RoomUpdatedEvent;
 import io.f1.backend.domain.game.model.GameSetting;
@@ -8,14 +10,19 @@
 import io.f1.backend.domain.game.model.Room;
 import io.f1.backend.domain.game.model.RoomState;
 import io.f1.backend.domain.game.store.RoomRepository;
+import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.quiz.app.QuizService;
 import io.f1.backend.domain.quiz.entity.Quiz;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.GameErrorCode;
+import io.f1.backend.global.exception.errorcode.RoomErrorCode;
 
 import lombok.RequiredArgsConstructor;
 
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 
+import java.util.List;
 import java.util.Map;
 
 @Service
@@ -26,15 +33,17 @@ public class GameService {
     private final RoomRepository roomRepository;
     private final ApplicationEventPublisher eventPublisher;
 
-    public GameStartData gameStart(Long roomId, Long quizId) {
+    public GameStartResponse gameStart(Long roomId, GameStartRequest gameStartRequest) {
+
+        Long quizId = gameStartRequest.quizId();
 
         Room room =
                 roomRepository
                         .findRoom(roomId)
-                        .orElseThrow(() -> new IllegalArgumentException("404 존재하지 않는 방입니다."));
+                        .orElseThrow(() -> new CustomException(RoomErrorCode.ROOM_NOT_FOUND));
 
         if (!validateReadyStatus(room)) {
-            throw new IllegalArgumentException("E403004 : 레디 상태가 아닙니다.");
+            throw new CustomException(RoomErrorCode.PLAYER_NOT_READY);
         }
 
         // 방의 gameSetting에 설정된 퀴즈랑 요청 퀴즈랑 같은지 체크 후 GameSetting에서 라운드 가져오기
@@ -43,22 +52,25 @@ public GameStartData gameStart(Long roomId, Long quizId) {
         Quiz quiz = quizService.getQuizWithQuestionsById(quizId);
 
         // 라운드 수만큼 랜덤 Question 추출
-        GameStartResponse questions = quizService.getRandomQuestionsWithoutAnswer(quizId, round);
+        List<Question> questions = quizService.getRandomQuestionsWithoutAnswer(quizId, round);
+        room.updateQuestions(questions);
+
+        GameStartResponse gameStartResponse = toGameStartResponse(questions);
 
         // 방 정보 게임 중으로 변경
         room.updateRoomState(RoomState.PLAYING);
 
         eventPublisher.publishEvent(new RoomUpdatedEvent(room, quiz));
 
-        return new GameStartData(getDestination(roomId), questions);
+        return gameStartResponse;
     }
 
     private Integer checkGameSetting(Room room, Long quizId) {
 
         GameSetting gameSetting = room.getGameSetting();
 
-        if (!gameSetting.checkQuizId(quizId)) {
-            throw new IllegalArgumentException("E409002 : 게임 설정이 다릅니다. (게임을 시작할 수 없습니다.)");
+        if (!gameSetting.validateQuizId(quizId)) {
+            throw new CustomException(GameErrorCode.GAME_SETTING_CONFLICT);
         }
 
         return gameSetting.getRound();
@@ -70,8 +82,4 @@ private boolean validateReadyStatus(Room room) {
 
         return playerSessionMap.values().stream().allMatch(Player::isReady);
     }
-
-    private static String getDestination(Long roomId) {
-        return "/sub/room/" + roomId;
-    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/app/RoomService.java b/backend/src/main/java/io/f1/backend/domain/game/app/RoomService.java
index d4544e9f..e96bdec9 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/app/RoomService.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/app/RoomService.java
@@ -4,15 +4,19 @@
 import static io.f1.backend.domain.game.mapper.RoomMapper.toGameSetting;
 import static io.f1.backend.domain.game.mapper.RoomMapper.toGameSettingResponse;
 import static io.f1.backend.domain.game.mapper.RoomMapper.toPlayerListResponse;
+import static io.f1.backend.domain.game.mapper.RoomMapper.toQuestionResultResponse;
+import static io.f1.backend.domain.game.mapper.RoomMapper.toRankUpdateResponse;
 import static io.f1.backend.domain.game.mapper.RoomMapper.toRoomResponse;
 import static io.f1.backend.domain.game.mapper.RoomMapper.toRoomSetting;
 import static io.f1.backend.domain.game.mapper.RoomMapper.toRoomSettingResponse;
 import static io.f1.backend.global.util.SecurityUtils.getCurrentUserId;
 import static io.f1.backend.global.util.SecurityUtils.getCurrentUserNickname;
 
+import io.f1.backend.domain.game.dto.ChatMessage;
 import io.f1.backend.domain.game.dto.RoomEventType;
 import io.f1.backend.domain.game.dto.RoomExitData;
 import io.f1.backend.domain.game.dto.RoomInitialData;
+import io.f1.backend.domain.game.dto.RoundResult;
 import io.f1.backend.domain.game.dto.request.RoomCreateRequest;
 import io.f1.backend.domain.game.dto.request.RoomValidationRequest;
 import io.f1.backend.domain.game.dto.response.GameSettingResponse;
@@ -22,15 +26,17 @@
 import io.f1.backend.domain.game.dto.response.RoomResponse;
 import io.f1.backend.domain.game.dto.response.RoomSettingResponse;
 import io.f1.backend.domain.game.dto.response.SystemNoticeResponse;
-import io.f1.backend.domain.game.event.RoomCreatedEvent;
 import io.f1.backend.domain.game.model.GameSetting;
 import io.f1.backend.domain.game.model.Player;
 import io.f1.backend.domain.game.model.Room;
 import io.f1.backend.domain.game.model.RoomSetting;
 import io.f1.backend.domain.game.model.RoomState;
 import io.f1.backend.domain.game.store.RoomRepository;
+import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.quiz.app.QuizService;
+import io.f1.backend.domain.quiz.dto.QuizMinData;
 import io.f1.backend.domain.quiz.entity.Quiz;
+import io.f1.backend.domain.user.dto.UserPrincipal;
 import io.f1.backend.global.exception.CustomException;
 import io.f1.backend.global.exception.errorcode.RoomErrorCode;
 
@@ -60,10 +66,10 @@ public class RoomService {
 
     public RoomCreateResponse saveRoom(RoomCreateRequest request) {
 
-        Long quizMinId = quizService.getQuizMinId();
-        Quiz quiz = quizService.getQuizWithQuestionsById(quizMinId);
+        QuizMinData quizMinData = quizService.getQuizMinData();
+        // Quiz quiz = quizService.getQuizWithQuestionsById(quizMinId);
 
-        GameSetting gameSetting = toGameSetting(quiz);
+        GameSetting gameSetting = toGameSetting(quizMinData);
 
         Player host = createPlayer();
 
@@ -77,7 +83,7 @@ public RoomCreateResponse saveRoom(RoomCreateRequest request) {
 
         roomRepository.saveRoom(room);
 
-        eventPublisher.publishEvent(new RoomCreatedEvent(room, quiz));
+        // eventPublisher.publishEvent(new RoomCreatedEvent(room, quiz));
 
         return new RoomCreateResponse(newId);
     }
@@ -110,11 +116,12 @@ public void enterRoom(RoomValidationRequest request) {
         }
     }
 
-    public RoomInitialData initializeRoomSocket(Long roomId, String sessionId) {
+    public RoomInitialData initializeRoomSocket(
+            Long roomId, String sessionId, UserPrincipal principal) {
 
         Room room = findRoom(roomId);
 
-        Player player = createPlayer();
+        Player player = createPlayer(principal);
 
         Map<String, Player> playerSessionMap = room.getPlayerSessionMap();
         Map<Long, String> userIdSessionMap = room.getUserIdSessionMap();
@@ -140,30 +147,25 @@ public RoomInitialData initializeRoomSocket(Long roomId, String sessionId) {
 
         PlayerListResponse playerListResponse = toPlayerListResponse(room);
 
-        SystemNoticeResponse systemNoticeResponse = ofPlayerEvent(player, RoomEventType.ENTER);
+        SystemNoticeResponse systemNoticeResponse =
+                ofPlayerEvent(player.getNickname(), RoomEventType.ENTER);
 
         return new RoomInitialData(
-                getDestination(roomId),
-                roomSettingResponse,
-                gameSettingResponse,
-                playerListResponse,
-                systemNoticeResponse);
+                roomSettingResponse, gameSettingResponse, playerListResponse, systemNoticeResponse);
     }
 
-    public RoomExitData exitRoom(Long roomId, String sessionId) {
+    public RoomExitData exitRoom(Long roomId, String sessionId, UserPrincipal principal) {
 
         Object lock = roomLocks.computeIfAbsent(roomId, k -> new Object());
 
         synchronized (lock) {
             Room room = findRoom(roomId);
 
-            String destination = getDestination(roomId);
-
-            Player removePlayer = getRemovePlayer(room, sessionId);
+            Player removePlayer = getRemovePlayer(room, sessionId, principal);
 
             /* 방 삭제 */
             if (isLastPlayer(room, sessionId)) {
-                return removeRoom(room, destination);
+                return removeRoom(room);
             }
 
             /* 방장 변경 */
@@ -175,14 +177,27 @@ public RoomExitData exitRoom(Long roomId, String sessionId) {
             removePlayer(room, sessionId, removePlayer);
 
             SystemNoticeResponse systemNoticeResponse =
-                    ofPlayerEvent(removePlayer, RoomEventType.EXIT);
+                    ofPlayerEvent(removePlayer.nickname, RoomEventType.EXIT);
 
             PlayerListResponse playerListResponse = toPlayerListResponse(room);
 
-            return new RoomExitData(destination, playerListResponse, systemNoticeResponse, false);
+            return new RoomExitData(playerListResponse, systemNoticeResponse, false);
         }
     }
 
+    public PlayerListResponse handlePlayerReady(Long roomId, String sessionId) {
+        Player player =
+                roomRepository
+                        .findPlayerInRoomBySessionId(roomId, sessionId)
+                        .orElseThrow(() -> new CustomException(RoomErrorCode.PLAYER_NOT_FOUND));
+
+        player.toggleReady();
+
+        Room room = findRoom(roomId);
+
+        return toPlayerListResponse(room);
+    }
+
     public RoomListResponse getAllRooms() {
         List<Room> rooms = roomRepository.findAll();
         List<RoomResponse> roomResponses =
@@ -198,17 +213,44 @@ public RoomListResponse getAllRooms() {
         return new RoomListResponse(roomResponses);
     }
 
-    private Player getRemovePlayer(Room room, String sessionId) {
+    // todo 동시성적용
+    public RoundResult chat(Long roomId, String sessionId, ChatMessage chatMessage) {
+        Room room = findRoom(roomId);
+
+        if (!room.isPlaying()) {
+            return buildResultOnlyChat(chatMessage);
+        }
+
+        Question currentQuestion = room.getCurrentQuestion();
+
+        String answer = currentQuestion.getAnswer();
+
+        if (!answer.equals(chatMessage.message())) {
+            return buildResultOnlyChat(chatMessage);
+        }
+
+        room.increasePlayerCorrectCount(sessionId);
+
+        return RoundResult.builder()
+                .questionResult(
+                        toQuestionResultResponse(currentQuestion.getId(), chatMessage, answer))
+                .rankUpdate(toRankUpdateResponse(room))
+                .systemNotice(ofPlayerEvent(chatMessage.nickname(), RoomEventType.ENTER))
+                .chat(chatMessage)
+                .build();
+    }
+
+    private Player getRemovePlayer(Room room, String sessionId, UserPrincipal principal) {
         Player removePlayer = room.getPlayerSessionMap().get(sessionId);
         if (removePlayer == null) {
-            room.removeUserId(getCurrentUserId());
+            room.removeUserId(principal.getUserId());
             throw new CustomException(RoomErrorCode.SOCKET_SESSION_NOT_FOUND);
         }
         return removePlayer;
     }
 
-    private static String getDestination(Long roomId) {
-        return "/sub/room/" + roomId;
+    private Player createPlayer(UserPrincipal principal) {
+        return new Player(principal.getUserId(), principal.getUserNickname());
     }
 
     private Player createPlayer() {
@@ -226,12 +268,12 @@ private boolean isLastPlayer(Room room, String sessionId) {
         return playerSessionMap.size() == 1 && playerSessionMap.containsKey(sessionId);
     }
 
-    private RoomExitData removeRoom(Room room, String destination) {
+    private RoomExitData removeRoom(Room room) {
         Long roomId = room.getId();
         roomRepository.removeRoom(roomId);
         roomLocks.remove(roomId);
         log.info("{}번 방 삭제", roomId);
-        return RoomExitData.builder().destination(destination).removedRoom(true).build();
+        return RoomExitData.builder().removedRoom(true).build();
     }
 
     private void changeHost(Room room, String hostSessionId) {
@@ -255,4 +297,8 @@ private void removePlayer(Room room, String sessionId, Player removePlayer) {
         room.removeUserId(removePlayer.getId());
         room.removeSessionId(sessionId);
     }
+
+    private RoundResult buildResultOnlyChat(ChatMessage chatMessage) {
+        return RoundResult.builder().chat(chatMessage).build();
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/ChatMessage.java b/backend/src/main/java/io/f1/backend/domain/game/dto/ChatMessage.java
new file mode 100644
index 00000000..da1bb4ea
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/ChatMessage.java
@@ -0,0 +1,5 @@
+package io.f1.backend.domain.game.dto;
+
+import java.time.Instant;
+
+public record ChatMessage(String nickname, String message, Instant timestamp) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/GameStartData.java b/backend/src/main/java/io/f1/backend/domain/game/dto/GameStartData.java
deleted file mode 100644
index c68d056e..00000000
--- a/backend/src/main/java/io/f1/backend/domain/game/dto/GameStartData.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package io.f1.backend.domain.game.dto;
-
-import io.f1.backend.domain.game.dto.response.GameStartResponse;
-
-public record GameStartData(String destination, GameStartResponse gameStartResponse) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/MessageType.java b/backend/src/main/java/io/f1/backend/domain/game/dto/MessageType.java
index 22dfdee2..7e5384eb 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/dto/MessageType.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/MessageType.java
@@ -6,4 +6,7 @@ public enum MessageType {
     PLAYER_LIST,
     SYSTEM_NOTICE,
     GAME_START,
+    CHAT,
+    QUESTION_RESULT,
+    RANK_UPDATE,
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/Rank.java b/backend/src/main/java/io/f1/backend/domain/game/dto/Rank.java
new file mode 100644
index 00000000..04fc4600
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/Rank.java
@@ -0,0 +1,3 @@
+package io.f1.backend.domain.game.dto;
+
+public record Rank(String nickname, int correctCount) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/RoomExitData.java b/backend/src/main/java/io/f1/backend/domain/game/dto/RoomExitData.java
index 1fc51f2e..76efee90 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/dto/RoomExitData.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/RoomExitData.java
@@ -9,18 +9,15 @@
 @Getter
 public class RoomExitData {
 
-    private final String destination;
     private final PlayerListResponse playerListResponses;
     private final SystemNoticeResponse systemNoticeResponse;
     private final boolean removedRoom;
 
     @Builder
     public RoomExitData(
-            String destination,
             PlayerListResponse playerListResponses,
             SystemNoticeResponse systemNoticeResponse,
             boolean removedRoom) {
-        this.destination = destination;
         this.playerListResponses = playerListResponses;
         this.systemNoticeResponse = systemNoticeResponse;
         this.removedRoom = removedRoom;
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/RoomInitialData.java b/backend/src/main/java/io/f1/backend/domain/game/dto/RoomInitialData.java
index c925b690..439daca8 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/dto/RoomInitialData.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/RoomInitialData.java
@@ -6,7 +6,6 @@
 import io.f1.backend.domain.game.dto.response.SystemNoticeResponse;
 
 public record RoomInitialData(
-        String destination,
         RoomSettingResponse roomSettingResponse,
         GameSettingResponse gameSettingResponse,
         PlayerListResponse playerListResponse,
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/RoundResult.java b/backend/src/main/java/io/f1/backend/domain/game/dto/RoundResult.java
new file mode 100644
index 00000000..6a537b3d
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/RoundResult.java
@@ -0,0 +1,36 @@
+package io.f1.backend.domain.game.dto;
+
+import io.f1.backend.domain.game.dto.response.QuestionResultResponse;
+import io.f1.backend.domain.game.dto.response.RankUpdateResponse;
+import io.f1.backend.domain.game.dto.response.SystemNoticeResponse;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+public class RoundResult {
+    QuestionResultResponse questionResult;
+    RankUpdateResponse rankUpdate;
+    SystemNoticeResponse systemNotice;
+    ChatMessage chat;
+
+    @Builder
+    public RoundResult(
+            QuestionResultResponse questionResult,
+            RankUpdateResponse rankUpdate,
+            SystemNoticeResponse systemNotice,
+            ChatMessage chat) {
+        this.questionResult = questionResult;
+        this.rankUpdate = rankUpdate;
+        this.systemNotice = systemNotice;
+        this.chat = chat;
+    }
+
+    public boolean hasChat() {
+        return chat != null;
+    }
+
+    public boolean hasOnlyChat() {
+        return chat != null && questionResult == null && rankUpdate == null && systemNotice == null;
+    }
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/request/DefaultWebSocketRequest.java b/backend/src/main/java/io/f1/backend/domain/game/dto/request/DefaultWebSocketRequest.java
new file mode 100644
index 00000000..a95981e4
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/request/DefaultWebSocketRequest.java
@@ -0,0 +1,14 @@
+package io.f1.backend.domain.game.dto.request;
+
+import io.f1.backend.domain.game.dto.MessageType;
+import io.f1.backend.domain.game.dto.WebSocketDto;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class DefaultWebSocketRequest<T> implements WebSocketDto<T> {
+    private final MessageType type;
+    private final T message;
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/response/QuestionResultResponse.java b/backend/src/main/java/io/f1/backend/domain/game/dto/response/QuestionResultResponse.java
new file mode 100644
index 00000000..5d8c131e
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/response/QuestionResultResponse.java
@@ -0,0 +1,3 @@
+package io.f1.backend.domain.game.dto.response;
+
+public record QuestionResultResponse(Long questionId, String correctUser, String answer) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/dto/response/RankUpdateResponse.java b/backend/src/main/java/io/f1/backend/domain/game/dto/response/RankUpdateResponse.java
new file mode 100644
index 00000000..68cf3ce2
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/game/dto/response/RankUpdateResponse.java
@@ -0,0 +1,7 @@
+package io.f1.backend.domain.game.dto.response;
+
+import io.f1.backend.domain.game.dto.Rank;
+
+import java.util.List;
+
+public record RankUpdateResponse(List<Rank> rank) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/game/mapper/RoomMapper.java b/backend/src/main/java/io/f1/backend/domain/game/mapper/RoomMapper.java
index cd3d109f..3ec0bbc9 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/mapper/RoomMapper.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/mapper/RoomMapper.java
@@ -1,11 +1,15 @@
 package io.f1.backend.domain.game.mapper;
 
+import io.f1.backend.domain.game.dto.ChatMessage;
+import io.f1.backend.domain.game.dto.Rank;
 import io.f1.backend.domain.game.dto.RoomEventType;
 import io.f1.backend.domain.game.dto.request.RoomCreateRequest;
 import io.f1.backend.domain.game.dto.response.GameSettingResponse;
 import io.f1.backend.domain.game.dto.response.PlayerListResponse;
 import io.f1.backend.domain.game.dto.response.PlayerResponse;
+import io.f1.backend.domain.game.dto.response.QuestionResultResponse;
 import io.f1.backend.domain.game.dto.response.QuizResponse;
+import io.f1.backend.domain.game.dto.response.RankUpdateResponse;
 import io.f1.backend.domain.game.dto.response.RoomResponse;
 import io.f1.backend.domain.game.dto.response.RoomSettingResponse;
 import io.f1.backend.domain.game.dto.response.SystemNoticeResponse;
@@ -13,9 +17,11 @@
 import io.f1.backend.domain.game.model.Player;
 import io.f1.backend.domain.game.model.Room;
 import io.f1.backend.domain.game.model.RoomSetting;
+import io.f1.backend.domain.quiz.dto.QuizMinData;
 import io.f1.backend.domain.quiz.entity.Quiz;
 
 import java.time.Instant;
+import java.util.Comparator;
 import java.util.List;
 
 public class RoomMapper {
@@ -27,8 +33,11 @@ public static RoomSetting toRoomSetting(RoomCreateRequest request) {
                 request.roomName(), request.maxUserCount(), request.locked(), request.password());
     }
 
-    public static GameSetting toGameSetting(Quiz quiz) {
-        return new GameSetting(quiz.getId(), quiz.getQuestions().size(), DEFAULT_TIME_LIMIT);
+    public static GameSetting toGameSetting(QuizMinData quizMinData) {
+        return new GameSetting(
+                quizMinData.quizMinId(),
+                quizMinData.questionCount().intValue(),
+                DEFAULT_TIME_LIMIT);
     }
 
     public static RoomSettingResponse toRoomSettingResponse(Room room) {
@@ -76,13 +85,26 @@ public static QuizResponse toQuizResponse(Quiz quiz) {
                 quiz.getQuestions().size());
     }
 
-    public static SystemNoticeResponse ofPlayerEvent(Player player, RoomEventType roomEventType) {
+    public static SystemNoticeResponse ofPlayerEvent(String nickname, RoomEventType roomEventType) {
         String message = "";
         if (roomEventType == RoomEventType.ENTER) {
             message = " 님이 입장하셨습니다";
         } else if (roomEventType == RoomEventType.EXIT) {
             message = " 님이 퇴장하셨습니다";
         }
-        return new SystemNoticeResponse(player.getNickname() + message, Instant.now());
+        return new SystemNoticeResponse(nickname + message, Instant.now());
+    }
+
+    public static QuestionResultResponse toQuestionResultResponse(
+            Long questionId, ChatMessage chatMessage, String answer) {
+        return new QuestionResultResponse(questionId, chatMessage.nickname(), answer);
+    }
+
+    public static RankUpdateResponse toRankUpdateResponse(Room room) {
+        return new RankUpdateResponse(
+                room.getPlayerSessionMap().values().stream()
+                        .sorted(Comparator.comparing(Player::getCorrectCount).reversed())
+                        .map(player -> new Rank(player.getNickname(), player.getCorrectCount()))
+                        .toList());
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/model/GameSetting.java b/backend/src/main/java/io/f1/backend/domain/game/model/GameSetting.java
index 7634d114..0b8b17e1 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/model/GameSetting.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/model/GameSetting.java
@@ -3,6 +3,8 @@
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 
+import java.util.Objects;
+
 @Getter
 @AllArgsConstructor
 public class GameSetting {
@@ -11,10 +13,7 @@ public class GameSetting {
     private Integer round; // 게임 변경 시 해당 게임의 총 문제 수로 설정
     private int timeLimit = 60;
 
-    public boolean checkQuizId(Long quizId) {
-        if (this.quizId != null && this.quizId.equals(quizId)) {
-            return false;
-        }
-        return true;
+    public boolean validateQuizId(Long quizId) {
+        return Objects.equals(this.quizId, quizId);
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/model/Player.java b/backend/src/main/java/io/f1/backend/domain/game/model/Player.java
index a5b1241c..4d054c8c 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/model/Player.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/model/Player.java
@@ -23,4 +23,8 @@ public Player(Long id, String nickname) {
     public void toggleReady() {
         this.isReady = !this.isReady;
     }
+
+    public void increaseCorrectCount() {
+        correctCount++;
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/model/Room.java b/backend/src/main/java/io/f1/backend/domain/game/model/Room.java
index d42abc8d..82b4b18e 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/model/Room.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/model/Room.java
@@ -31,6 +31,8 @@ public class Room {
 
     private final LocalDateTime createdAt = LocalDateTime.now();
 
+    private int currentRound = 0;
+
     public Room(Long id, RoomSetting roomSetting, GameSetting gameSetting, Player host) {
         this.id = id;
         this.roomSetting = roomSetting;
@@ -42,6 +44,10 @@ public boolean isHost(Long id) {
         return this.host.getId().equals(id);
     }
 
+    public void updateQuestions(List<Question> questions) {
+        this.questions = questions;
+    }
+
     public void updateHost(Player nextHost) {
         this.host = nextHost;
     }
@@ -57,4 +63,20 @@ public void removeUserId(Long id) {
     public void removeSessionId(String sessionId) {
         this.playerSessionMap.remove(sessionId);
     }
+
+    public void increasePlayerCorrectCount(String sessionId) {
+        this.playerSessionMap.get(sessionId).increaseCorrectCount();
+    }
+
+    public Question getCurrentQuestion() {
+        return questions.get(currentRound - 1);
+    }
+
+    public Boolean isPlaying() {
+        return state == RoomState.PLAYING;
+    }
+
+    public void increaseCorrectCount() {
+        currentRound++;
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepository.java b/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepository.java
index 6e87760d..f2852c5d 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepository.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepository.java
@@ -1,11 +1,13 @@
 package io.f1.backend.domain.game.store;
 
+import io.f1.backend.domain.game.model.Player;
 import io.f1.backend.domain.game.model.Room;
 
 import java.util.List;
 import java.util.Optional;
 
 public interface RoomRepository {
+
     void saveRoom(Room room);
 
     Optional<Room> findRoom(Long roomId);
@@ -13,4 +15,6 @@ public interface RoomRepository {
     List<Room> findAll();
 
     void removeRoom(Long roomId);
+
+    Optional<Player> findPlayerInRoomBySessionId(Long roomId, String sessionId);
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepositoryImpl.java b/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepositoryImpl.java
index cffbba47..7efd4d9e 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepositoryImpl.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/store/RoomRepositoryImpl.java
@@ -1,5 +1,6 @@
 package io.f1.backend.domain.game.store;
 
+import io.f1.backend.domain.game.model.Player;
 import io.f1.backend.domain.game.model.Room;
 
 import org.springframework.stereotype.Repository;
@@ -35,6 +36,11 @@ public void removeRoom(Long roomId) {
         roomMap.remove(roomId);
     }
 
+    @Override
+    public Optional<Player> findPlayerInRoomBySessionId(Long roomId, String sessionId) {
+        return findRoom(roomId).map(room -> room.getPlayerSessionMap().get(sessionId));
+    }
+
     // 테스트 전용 메소드
     public Room getRoomForTest(Long roomId) {
         return roomMap.get(roomId);
diff --git a/backend/src/main/java/io/f1/backend/domain/game/websocket/GameSocketController.java b/backend/src/main/java/io/f1/backend/domain/game/websocket/GameSocketController.java
index e84e9c36..d51c18f2 100644
--- a/backend/src/main/java/io/f1/backend/domain/game/websocket/GameSocketController.java
+++ b/backend/src/main/java/io/f1/backend/domain/game/websocket/GameSocketController.java
@@ -2,11 +2,16 @@
 
 import io.f1.backend.domain.game.app.GameService;
 import io.f1.backend.domain.game.app.RoomService;
-import io.f1.backend.domain.game.dto.GameStartData;
+import io.f1.backend.domain.game.dto.ChatMessage;
 import io.f1.backend.domain.game.dto.MessageType;
 import io.f1.backend.domain.game.dto.RoomExitData;
 import io.f1.backend.domain.game.dto.RoomInitialData;
+import io.f1.backend.domain.game.dto.RoundResult;
+import io.f1.backend.domain.game.dto.request.DefaultWebSocketRequest;
 import io.f1.backend.domain.game.dto.request.GameStartRequest;
+import io.f1.backend.domain.game.dto.response.GameStartResponse;
+import io.f1.backend.domain.game.dto.response.PlayerListResponse;
+import io.f1.backend.domain.user.dto.UserPrincipal;
 
 import lombok.RequiredArgsConstructor;
 
@@ -14,6 +19,7 @@
 import org.springframework.messaging.handler.annotation.DestinationVariable;
 import org.springframework.messaging.handler.annotation.MessageMapping;
 import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
+import org.springframework.security.core.Authentication;
 import org.springframework.stereotype.Controller;
 
 @Controller
@@ -29,9 +35,12 @@ public void initializeRoomSocket(@DestinationVariable Long roomId, Message<?> me
 
         String websocketSessionId = getSessionId(message);
 
+        UserPrincipal principal = getSessionUser(message);
+
         RoomInitialData roomInitialData =
-                roomService.initializeRoomSocket(roomId, websocketSessionId);
-        String destination = roomInitialData.destination();
+                roomService.initializeRoomSocket(roomId, websocketSessionId, principal);
+
+        String destination = getDestination(roomId);
 
         messageSender.send(
                 destination, MessageType.ROOM_SETTING, roomInitialData.roomSettingResponse());
@@ -47,10 +56,11 @@ public void initializeRoomSocket(@DestinationVariable Long roomId, Message<?> me
     public void exitRoom(@DestinationVariable Long roomId, Message<?> message) {
 
         String websocketSessionId = getSessionId(message);
+        UserPrincipal principal = getSessionUser(message);
 
-        RoomExitData roomExitData = roomService.exitRoom(roomId, websocketSessionId);
+        RoomExitData roomExitData = roomService.exitRoom(roomId, websocketSessionId, principal);
 
-        String destination = roomExitData.getDestination();
+        String destination = getDestination(roomId);
 
         if (!roomExitData.isRemovedRoom()) {
             messageSender.send(
@@ -61,19 +71,59 @@ public void exitRoom(@DestinationVariable Long roomId, Message<?> message) {
     }
 
     @MessageMapping("/room/start/{roomId}")
-    public void gameStart(@DestinationVariable Long roomId, Message<GameStartRequest> message) {
+    public void gameStart(
+            @DestinationVariable Long roomId,
+            Message<DefaultWebSocketRequest<GameStartRequest>> message) {
+
+        GameStartResponse gameStartResponse =
+                gameService.gameStart(roomId, message.getPayload().getMessage());
+
+        String destination = getDestination(roomId);
+
+        messageSender.send(destination, MessageType.GAME_START, gameStartResponse);
+    }
+
+    @MessageMapping("room/chat/{roomId}")
+    public void chat(
+            @DestinationVariable Long roomId,
+            Message<DefaultWebSocketRequest<ChatMessage>> message) {
+        RoundResult roundResult =
+                roomService.chat(roomId, getSessionId(message), message.getPayload().getMessage());
+
+        String destination = getDestination(roomId);
+
+        messageSender.send(destination, MessageType.CHAT, roundResult.getChat());
 
-        Long quizId = message.getPayload().quizId();
+        if (!roundResult.hasOnlyChat()) {
+            messageSender.send(
+                    destination, MessageType.QUESTION_RESULT, roundResult.getQuestionResult());
+            messageSender.send(destination, MessageType.RANK_UPDATE, roundResult.getRankUpdate());
+            messageSender.send(
+                    destination, MessageType.SYSTEM_NOTICE, roundResult.getSystemNotice());
+        }
+    }
 
-        GameStartData gameStartData = gameService.gameStart(roomId, quizId);
+    @MessageMapping("/room/ready/{roomId}")
+    public void playerReady(@DestinationVariable Long roomId, Message<?> message) {
 
-        String destination = gameStartData.destination();
+        PlayerListResponse playerListResponse =
+                roomService.handlePlayerReady(roomId, getSessionId(message));
 
-        messageSender.send(destination, MessageType.GAME_START, gameStartData.gameStartResponse());
+        messageSender.send(getDestination(roomId), MessageType.PLAYER_LIST, playerListResponse);
     }
 
     private static String getSessionId(Message<?> message) {
         StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
         return accessor.getSessionId();
     }
+
+    private static UserPrincipal getSessionUser(Message<?> message) {
+        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
+        Authentication auth = (Authentication) accessor.getUser();
+        return (UserPrincipal) auth.getPrincipal();
+    }
+
+    private String getDestination(Long roomId) {
+        return "/sub/room/" + roomId;
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/question/app/QuestionService.java b/backend/src/main/java/io/f1/backend/domain/question/app/QuestionService.java
index 6fc7c954..277353b1 100644
--- a/backend/src/main/java/io/f1/backend/domain/question/app/QuestionService.java
+++ b/backend/src/main/java/io/f1/backend/domain/question/app/QuestionService.java
@@ -9,14 +9,14 @@
 import io.f1.backend.domain.question.entity.Question;
 import io.f1.backend.domain.question.entity.TextQuestion;
 import io.f1.backend.domain.quiz.entity.Quiz;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.QuestionErrorCode;
 
 import lombok.RequiredArgsConstructor;
 
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
-import java.util.NoSuchElementException;
-
 @Service
 @RequiredArgsConstructor
 public class QuestionService {
@@ -44,7 +44,8 @@ public void updateQuestionContent(Long questionId, String content) {
         Question question =
                 questionRepository
                         .findById(questionId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 문제입니다."));
+                        .orElseThrow(
+                                () -> new CustomException(QuestionErrorCode.QUESTION_NOT_FOUND));
 
         TextQuestion textQuestion = question.getTextQuestion();
         textQuestion.changeContent(content);
@@ -58,7 +59,8 @@ public void updateQuestionAnswer(Long questionId, String answer) {
         Question question =
                 questionRepository
                         .findById(questionId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 문제입니다."));
+                        .orElseThrow(
+                                () -> new CustomException(QuestionErrorCode.QUESTION_NOT_FOUND));
 
         question.changeAnswer(answer);
     }
@@ -69,20 +71,21 @@ public void deleteQuestion(Long questionId) {
         Question question =
                 questionRepository
                         .findById(questionId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 문제입니다."));
+                        .orElseThrow(
+                                () -> new CustomException(QuestionErrorCode.QUESTION_NOT_FOUND));
 
         questionRepository.delete(question);
     }
 
     private void validateAnswer(String answer) {
         if (answer.trim().length() < 5 || answer.trim().length() > 30) {
-            throw new IllegalArgumentException("정답은 1자 이상 30자 이하로 입력해주세요.");
+            throw new CustomException(QuestionErrorCode.INVALID_ANSWER_LENGTH);
         }
     }
 
     private void validateContent(String content) {
         if (content.trim().length() < 5 || content.trim().length() > 30) {
-            throw new IllegalArgumentException("문제는 5자 이상 30자 이하로 입력해주세요.");
+            throw new CustomException(QuestionErrorCode.INVALID_CONTENT_LENGTH);
         }
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/api/QuizController.java b/backend/src/main/java/io/f1/backend/domain/quiz/api/QuizController.java
index ee8d03a6..4d7a0d60 100644
--- a/backend/src/main/java/io/f1/backend/domain/quiz/api/QuizController.java
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/api/QuizController.java
@@ -6,6 +6,8 @@
 import io.f1.backend.domain.quiz.dto.QuizListPageResponse;
 import io.f1.backend.domain.quiz.dto.QuizQuestionListResponse;
 import io.f1.backend.domain.quiz.dto.QuizUpdateRequest;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.CommonErrorCode;
 
 import jakarta.validation.Valid;
 
@@ -28,8 +30,6 @@
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.multipart.MultipartFile;
 
-import java.io.IOException;
-
 @RestController
 @RequestMapping("/quizzes")
 @RequiredArgsConstructor
@@ -40,8 +40,7 @@ public class QuizController {
     @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     public ResponseEntity<QuizCreateResponse> saveQuiz(
             @RequestPart(required = false) MultipartFile thumbnailFile,
-            @Valid @RequestPart QuizCreateRequest request)
-            throws IOException {
+            @Valid @RequestPart QuizCreateRequest request) {
         QuizCreateResponse response = quizService.saveQuiz(thumbnailFile, request);
 
         return ResponseEntity.status(HttpStatus.CREATED).body(response);
@@ -58,8 +57,7 @@ public ResponseEntity<Void> deleteQuiz(@PathVariable Long quizId) {
     public ResponseEntity<Void> updateQuiz(
             @PathVariable Long quizId,
             @RequestPart(required = false) MultipartFile thumbnailFile,
-            @RequestPart QuizUpdateRequest request)
-            throws IOException {
+            @RequestPart QuizUpdateRequest request) {
 
         if (request.title() != null) {
             quizService.updateQuizTitle(quizId, request.title());
@@ -83,6 +81,13 @@ public ResponseEntity<QuizListPageResponse> getQuizzes(
             @RequestParam(required = false) String title,
             @RequestParam(required = false) String creator) {
 
+        if (page <= 0) {
+            throw new CustomException(CommonErrorCode.INVALID_PAGINATION);
+        }
+        if (size <= 0 || size > 100) {
+            throw new CustomException(CommonErrorCode.INVALID_PAGINATION);
+        }
+
         Pageable pageable =
                 PageRequest.of(page - 1, size, Sort.by(Sort.Direction.DESC, "createdAt"));
         QuizListPageResponse quizzes = quizService.getQuizzes(title, creator, pageable);
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/app/QuizService.java b/backend/src/main/java/io/f1/backend/domain/quiz/app/QuizService.java
index ce705fb6..3042f0a0 100644
--- a/backend/src/main/java/io/f1/backend/domain/quiz/app/QuizService.java
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/app/QuizService.java
@@ -4,7 +4,6 @@
 
 import static java.nio.file.Files.deleteIfExists;
 
-import io.f1.backend.domain.game.dto.response.GameStartResponse;
 import io.f1.backend.domain.question.app.QuestionService;
 import io.f1.backend.domain.question.dto.QuestionRequest;
 import io.f1.backend.domain.question.entity.Question;
@@ -13,10 +12,14 @@
 import io.f1.backend.domain.quiz.dto.QuizCreateResponse;
 import io.f1.backend.domain.quiz.dto.QuizListPageResponse;
 import io.f1.backend.domain.quiz.dto.QuizListResponse;
+import io.f1.backend.domain.quiz.dto.QuizMinData;
 import io.f1.backend.domain.quiz.dto.QuizQuestionListResponse;
 import io.f1.backend.domain.quiz.entity.Quiz;
 import io.f1.backend.domain.user.dao.UserRepository;
 import io.f1.backend.domain.user.entity.User;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.AuthErrorCode;
+import io.f1.backend.global.exception.errorcode.QuizErrorCode;
 
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -48,6 +51,7 @@ public class QuizService {
     private String defaultThumbnailPath;
 
     private final String DEFAULT = "default";
+    private static final long MAX_FILE_SIZE = 5 * 1024 * 1024; // 5MB
 
     // TODO : 시큐리티 구현 이후 삭제해도 되는 의존성 주입
     private final UserRepository userRepository;
@@ -55,8 +59,7 @@ public class QuizService {
     private final QuizRepository quizRepository;
 
     @Transactional
-    public QuizCreateResponse saveQuiz(MultipartFile thumbnailFile, QuizCreateRequest request)
-            throws IOException {
+    public QuizCreateResponse saveQuiz(MultipartFile thumbnailFile, QuizCreateRequest request) {
         String thumbnailPath = defaultThumbnailPath;
 
         if (thumbnailFile != null && !thumbnailFile.isEmpty()) {
@@ -81,29 +84,38 @@ public QuizCreateResponse saveQuiz(MultipartFile thumbnailFile, QuizCreateReques
     private void validateImageFile(MultipartFile thumbnailFile) {
 
         if (!thumbnailFile.getContentType().startsWith("image")) {
-            // TODO : 이후 커스텀 예외로 변경
-            throw new IllegalArgumentException("이미지 파일을 업로드해주세요.");
+            throw new CustomException(QuizErrorCode.UNSUPPORTED_MEDIA_TYPE);
         }
 
         List<String> allowedExt = List.of("jpg", "jpeg", "png", "webp");
-        if (!allowedExt.contains(getExtension(thumbnailFile.getOriginalFilename()))) {
-            throw new IllegalArgumentException("지원하지 않는 확장자입니다.");
+        String ext = getExtension(thumbnailFile.getOriginalFilename());
+        if (!allowedExt.contains(ext)) {
+            throw new CustomException(QuizErrorCode.UNSUPPORTED_IMAGE_FORMAT);
+        }
+
+        if (thumbnailFile.getSize() > MAX_FILE_SIZE) {
+            throw new CustomException(QuizErrorCode.FILE_SIZE_TOO_LARGE);
         }
     }
 
-    private String convertToThumbnailPath(MultipartFile thumbnailFile) throws IOException {
+    private String convertToThumbnailPath(MultipartFile thumbnailFile) {
         String originalFilename = thumbnailFile.getOriginalFilename();
         String ext = getExtension(originalFilename);
         String savedFilename = UUID.randomUUID().toString() + "." + ext;
 
-        Path savePath = Paths.get(uploadPath, savedFilename).toAbsolutePath();
-        thumbnailFile.transferTo(savePath.toFile());
+        try {
+            Path savePath = Paths.get(uploadPath, savedFilename).toAbsolutePath();
+            thumbnailFile.transferTo(savePath.toFile());
+        } catch (IOException e) {
+            log.error("썸네일 업로드 중 IOException 발생", e);
+            throw new CustomException(QuizErrorCode.THUMBNAIL_SAVE_FAILED);
+        }
 
         return "/images/thumbnail/" + savedFilename;
     }
 
     private String getExtension(String filename) {
-        return filename.substring(filename.lastIndexOf(".") + 1);
+        return filename.substring(filename.lastIndexOf(".") + 1).toLowerCase();
     }
 
     @Transactional
@@ -112,11 +124,11 @@ public void deleteQuiz(Long quizId) {
         Quiz quiz =
                 quizRepository
                         .findById(quizId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
 
         // TODO : util 메서드에서 사용자 ID 꺼내쓰는 식으로 수정하기
         if (1L != quiz.getCreator().getId()) {
-            throw new RuntimeException("권한이 없습니다.");
+            throw new CustomException(AuthErrorCode.FORBIDDEN);
         }
 
         deleteThumbnailFile(quiz.getThumbnailUrl());
@@ -128,7 +140,7 @@ public void updateQuizTitle(Long quizId, String title) {
         Quiz quiz =
                 quizRepository
                         .findById(quizId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
 
         validateTitle(title);
         quiz.changeTitle(title);
@@ -140,19 +152,19 @@ public void updateQuizDesc(Long quizId, String description) {
         Quiz quiz =
                 quizRepository
                         .findById(quizId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
 
         validateDesc(description);
         quiz.changeDescription(description);
     }
 
     @Transactional
-    public void updateThumbnail(Long quizId, MultipartFile thumbnailFile) throws IOException {
+    public void updateThumbnail(Long quizId, MultipartFile thumbnailFile) {
 
         Quiz quiz =
                 quizRepository
                         .findById(quizId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
 
         validateImageFile(thumbnailFile);
         String newThumbnailPath = convertToThumbnailPath(thumbnailFile);
@@ -163,13 +175,13 @@ public void updateThumbnail(Long quizId, MultipartFile thumbnailFile) throws IOE
 
     private void validateDesc(String desc) {
         if (desc.trim().length() < 10 || desc.trim().length() > 50) {
-            throw new IllegalArgumentException("설명은 10자 이상 50자 이하로 입력해주세요.");
+            throw new CustomException(QuizErrorCode.INVALID_DESC_LENGTH);
         }
     }
 
     private void validateTitle(String title) {
         if (title.trim().length() < 2 || title.trim().length() > 30) {
-            throw new IllegalArgumentException("제목은 2자 이상 30자 이하로 입력해주세요.");
+            throw new CustomException(QuizErrorCode.INVALID_TITLE_LENGTH);
         }
     }
 
@@ -192,7 +204,7 @@ private void deleteThumbnailFile(String oldFilename) {
             }
         } catch (IOException e) {
             log.error("기존 썸네일 삭제 중 오류 : {}", filePath);
-            throw new RuntimeException(e);
+            throw new CustomException(QuizErrorCode.THUMBNAIL_DELETE_FAILED);
         }
     }
 
@@ -202,9 +214,9 @@ public QuizListPageResponse getQuizzes(String title, String creator, Pageable pa
         Page<Quiz> quizzes;
 
         // 검색어가 있을 때
-        if (StringUtils.isBlank(title)) {
+        if (!StringUtils.isBlank(title)) {
             quizzes = quizRepository.findQuizzesByTitleContaining(title, pageable);
-        } else if (StringUtils.isBlank(creator)) {
+        } else if (!StringUtils.isBlank(creator)) {
             quizzes = quizRepository.findQuizzesByCreator_NicknameContaining(creator, pageable);
         } else { // 검색어가 없을 때 혹은 빈 문자열일 때
             quizzes = quizRepository.findAll(pageable);
@@ -220,13 +232,13 @@ public Quiz getQuizWithQuestionsById(Long quizId) {
         Quiz quiz =
                 quizRepository
                         .findQuizWithQuestionsById(quizId)
-                        .orElseThrow(() -> new RuntimeException("E404002: 존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
         return quiz;
     }
 
     @Transactional(readOnly = true)
-    public Long getQuizMinId() {
-        return quizRepository.getQuizMinId();
+    public QuizMinData getQuizMinData() {
+        return quizRepository.getQuizMinData();
     }
 
     @Transactional(readOnly = true)
@@ -234,19 +246,19 @@ public QuizQuestionListResponse getQuizWithQuestions(Long quizId) {
         Quiz quiz =
                 quizRepository
                         .findById(quizId)
-                        .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
+                        .orElseThrow(() -> new CustomException(QuizErrorCode.QUIZ_NOT_FOUND));
 
         return quizToQuizQuestionListResponse(quiz);
     }
 
     @Transactional(readOnly = true)
-    public GameStartResponse getRandomQuestionsWithoutAnswer(Long quizId, Integer round) {
+    public List<Question> getRandomQuestionsWithoutAnswer(Long quizId, Integer round) {
         quizRepository
                 .findById(quizId)
                 .orElseThrow(() -> new NoSuchElementException("존재하지 않는 퀴즈입니다."));
 
         List<Question> randomQuestions = quizRepository.findRandQuestionsByQuizId(quizId, round);
 
-        return toGameStartResponse(randomQuestions);
+        return randomQuestions;
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/dao/QuizRepository.java b/backend/src/main/java/io/f1/backend/domain/quiz/dao/QuizRepository.java
index b2d1728d..5c205705 100644
--- a/backend/src/main/java/io/f1/backend/domain/quiz/dao/QuizRepository.java
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/dao/QuizRepository.java
@@ -1,6 +1,7 @@
 package io.f1.backend.domain.quiz.dao;
 
 import io.f1.backend.domain.question.entity.Question;
+import io.f1.backend.domain.quiz.dto.QuizMinData;
 import io.f1.backend.domain.quiz.entity.Quiz;
 
 import org.springframework.data.domain.Page;
@@ -20,8 +21,15 @@ public interface QuizRepository extends JpaRepository<Quiz, Long> {
     @Query("SELECT q FROM Quiz q LEFT JOIN FETCH q.questions WHERE q.id = :quizId")
     Optional<Quiz> findQuizWithQuestionsById(Long quizId);
 
-    @Query("SELECT MIN(q.id) FROM Quiz q")
-    Long getQuizMinId();
+    @Query(
+"""
+    SELECT new io.f1.backend.domain.quiz.dto.QuizMinData (q.id, COUNT(qs.id))
+    FROM Quiz q
+    LEFT JOIN q.questions qs
+    WHERE q.id = (SELECT MIN(q2.id) FROM Quiz q2)
+    GROUP BY q.id
+""")
+    QuizMinData getQuizMinData();
 
     @Query(
             value = "SELECT * FROM question WHERE quiz_id = :quizId ORDER BY RAND() LIMIT :round",
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/dto/QuizMinData.java b/backend/src/main/java/io/f1/backend/domain/quiz/dto/QuizMinData.java
new file mode 100644
index 00000000..cb2b2074
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/dto/QuizMinData.java
@@ -0,0 +1,3 @@
+package io.f1.backend.domain.quiz.dto;
+
+public record QuizMinData(Long quizMinId, Long questionCount) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/entity/Quiz.java b/backend/src/main/java/io/f1/backend/domain/quiz/entity/Quiz.java
index fde07c7e..1cba9273 100644
--- a/backend/src/main/java/io/f1/backend/domain/quiz/entity/Quiz.java
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/entity/Quiz.java
@@ -50,7 +50,7 @@ public class Quiz extends BaseEntity {
     private String thumbnailUrl;
 
     @ManyToOne
-    @JoinColumn(name = "creator_id")
+    @JoinColumn(name = "creator_id", nullable = true)
     private User creator;
 
     public Quiz(
@@ -81,4 +81,20 @@ public void changeDescription(String description) {
     public void changeThumbnailUrl(String thumbnailUrl) {
         this.thumbnailUrl = thumbnailUrl;
     }
+
+    public Long findCreatorId() {
+        if (this.creator == null) {
+            return null;
+        }
+
+        return this.creator.getId();
+    }
+
+    public String findCreatorNickname() {
+        if (this.creator == null) {
+            return "탈퇴한 사용자";
+        }
+
+        return this.creator.getNickname();
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/quiz/mapper/QuizMapper.java b/backend/src/main/java/io/f1/backend/domain/quiz/mapper/QuizMapper.java
index 0c0c0513..b9dffc0e 100644
--- a/backend/src/main/java/io/f1/backend/domain/quiz/mapper/QuizMapper.java
+++ b/backend/src/main/java/io/f1/backend/domain/quiz/mapper/QuizMapper.java
@@ -39,7 +39,7 @@ public static QuizCreateResponse quizToQuizCreateResponse(Quiz quiz) {
                 quiz.getQuizType(),
                 quiz.getDescription(),
                 quiz.getThumbnailUrl(),
-                quiz.getCreator().getId());
+                quiz.findCreatorId());
     }
 
     public static QuizListResponse quizToQuizListResponse(Quiz quiz) {
@@ -47,7 +47,7 @@ public static QuizListResponse quizToQuizListResponse(Quiz quiz) {
                 quiz.getId(),
                 quiz.getTitle(),
                 quiz.getDescription(),
-                quiz.getCreator().getNickname(),
+                quiz.findCreatorNickname(),
                 quiz.getQuestions().size(),
                 quiz.getThumbnailUrl());
     }
@@ -79,7 +79,7 @@ public static QuizQuestionListResponse quizToQuizQuestionListResponse(Quiz quiz)
         return new QuizQuestionListResponse(
                 quiz.getTitle(),
                 quiz.getQuizType(),
-                quiz.getCreator().getId(),
+                quiz.findCreatorId(),
                 quiz.getDescription(),
                 quiz.getThumbnailUrl(),
                 quiz.getQuestions().size(),
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/api/StatController.java b/backend/src/main/java/io/f1/backend/domain/stat/api/StatController.java
new file mode 100644
index 00000000..38c14de8
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/api/StatController.java
@@ -0,0 +1,32 @@
+package io.f1.backend.domain.stat.api;
+
+import io.f1.backend.domain.stat.app.StatService;
+import io.f1.backend.domain.stat.dto.StatPageResponse;
+import io.f1.backend.global.validation.LimitPageSize;
+
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort.Direction;
+import org.springframework.data.web.PageableDefault;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/stats")
+public class StatController {
+
+    private final StatService statService;
+
+    @LimitPageSize
+    @GetMapping("/rankings")
+    public ResponseEntity<StatPageResponse> getRankings(
+            @PageableDefault(sort = "score", direction = Direction.DESC) Pageable pageable) {
+        StatPageResponse response = statService.getRanks(pageable);
+
+        return ResponseEntity.ok().body(response);
+    }
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/app/StatService.java b/backend/src/main/java/io/f1/backend/domain/stat/app/StatService.java
new file mode 100644
index 00000000..b123c80d
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/app/StatService.java
@@ -0,0 +1,25 @@
+package io.f1.backend.domain.stat.app;
+
+import static io.f1.backend.domain.stat.mapper.StatMapper.toStatListPageResponse;
+
+import io.f1.backend.domain.stat.dao.StatRepository;
+import io.f1.backend.domain.stat.dto.StatPageResponse;
+import io.f1.backend.domain.stat.dto.StatWithNickname;
+
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class StatService {
+
+    private final StatRepository statRepository;
+
+    public StatPageResponse getRanks(Pageable pageable) {
+        Page<StatWithNickname> stats = statRepository.findWithUser(pageable);
+        return toStatListPageResponse(stats);
+    }
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/dao/StatRepository.java b/backend/src/main/java/io/f1/backend/domain/stat/dao/StatRepository.java
new file mode 100644
index 00000000..912e735c
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/dao/StatRepository.java
@@ -0,0 +1,22 @@
+package io.f1.backend.domain.stat.dao;
+
+import io.f1.backend.domain.stat.dto.StatWithNickname;
+import io.f1.backend.domain.stat.entity.Stat;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+
+public interface StatRepository extends JpaRepository<Stat, Long> {
+
+    @Query(
+            """
+            SELECT
+            		new io.f1.backend.domain.stat.dto.StatWithNickname
+            				(u.nickname, s.totalGames, s.winningGames, s.score)
+            FROM
+            		Stat s JOIN s.user u
+            """)
+    Page<StatWithNickname> findWithUser(Pageable pageable);
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/dto/StatPageResponse.java b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatPageResponse.java
new file mode 100644
index 00000000..a33e9a4d
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatPageResponse.java
@@ -0,0 +1,6 @@
+package io.f1.backend.domain.stat.dto;
+
+import java.util.List;
+
+public record StatPageResponse(
+        int totalPages, int currentPage, int totalElements, List<StatResponse> ranks) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/dto/StatResponse.java b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatResponse.java
new file mode 100644
index 00000000..5dd3a88e
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatResponse.java
@@ -0,0 +1,4 @@
+package io.f1.backend.domain.stat.dto;
+
+public record StatResponse(
+        long rank, String nickname, long totalGames, long winningGames, long score) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/dto/StatWithNickname.java b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatWithNickname.java
new file mode 100644
index 00000000..e2596a06
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/dto/StatWithNickname.java
@@ -0,0 +1,3 @@
+package io.f1.backend.domain.stat.dto;
+
+public record StatWithNickname(String nickname, long totalGames, long winningGames, long score) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/stat/mapper/StatMapper.java b/backend/src/main/java/io/f1/backend/domain/stat/mapper/StatMapper.java
new file mode 100644
index 00000000..57956a32
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/domain/stat/mapper/StatMapper.java
@@ -0,0 +1,40 @@
+package io.f1.backend.domain.stat.mapper;
+
+import io.f1.backend.domain.stat.dto.StatPageResponse;
+import io.f1.backend.domain.stat.dto.StatResponse;
+import io.f1.backend.domain.stat.dto.StatWithNickname;
+
+import org.springframework.data.domain.Page;
+
+public class StatMapper {
+
+    public static StatPageResponse toStatListPageResponse(Page<StatWithNickname> statPage) {
+        int curPage = statPage.getNumber() + 1;
+
+        return new StatPageResponse(
+                statPage.getTotalPages(),
+                curPage,
+                statPage.getNumberOfElements(),
+                statPage.stream()
+                        .map(
+                                stat -> {
+                                    long rank =
+                                            getRankFromPage(
+                                                    curPage,
+                                                    statPage.getSize(),
+                                                    statPage.getContent().indexOf(stat));
+                                    return toStatResponse(stat, rank);
+                                })
+                        .toList());
+    }
+
+    private static StatResponse toStatResponse(StatWithNickname stat, long rank) {
+        return new StatResponse(
+                rank, stat.nickname(), stat.totalGames(), stat.winningGames(), stat.score());
+    }
+
+    private static long getRankFromPage(int curPage, int pageSize, int index) {
+        int startRank = (curPage - 1) * pageSize + 1;
+        return startRank + index;
+    }
+}
diff --git a/backend/src/main/java/io/f1/backend/domain/user/api/SignupController.java b/backend/src/main/java/io/f1/backend/domain/user/api/SignupController.java
index 9fa1d7de..e39abbc2 100644
--- a/backend/src/main/java/io/f1/backend/domain/user/api/SignupController.java
+++ b/backend/src/main/java/io/f1/backend/domain/user/api/SignupController.java
@@ -1,8 +1,8 @@
 package io.f1.backend.domain.user.api;
 
+import io.f1.backend.domain.auth.dto.CurrentUserAndAdminResponse;
 import io.f1.backend.domain.user.app.UserService;
 import io.f1.backend.domain.user.dto.SignupRequest;
-import io.f1.backend.domain.user.dto.SignupResponse;
 
 import jakarta.servlet.http.HttpSession;
 
@@ -10,8 +10,10 @@
 
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
@@ -21,9 +23,15 @@ public class SignupController {
     private final UserService userService;
 
     @PostMapping("/signup")
-    public ResponseEntity<SignupResponse> completeSignup(
+    public ResponseEntity<CurrentUserAndAdminResponse> completeSignup(
             @RequestBody SignupRequest signupRequest, HttpSession httpSession) {
-        SignupResponse response = userService.signup(httpSession, signupRequest);
+        CurrentUserAndAdminResponse response = userService.signup(httpSession, signupRequest);
         return ResponseEntity.status(HttpStatus.CREATED).body(response);
     }
+
+    @GetMapping("/check-nickname")
+    public ResponseEntity<Void> checkNicknameDuplicate(@RequestParam String nickname) {
+        userService.checkNickname(nickname);
+        return ResponseEntity.ok().build();
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/user/app/UserService.java b/backend/src/main/java/io/f1/backend/domain/user/app/UserService.java
index d2f035d9..bdf86e96 100644
--- a/backend/src/main/java/io/f1/backend/domain/user/app/UserService.java
+++ b/backend/src/main/java/io/f1/backend/domain/user/app/UserService.java
@@ -2,13 +2,16 @@
 
 import static io.f1.backend.domain.user.constants.SessionKeys.OAUTH_USER;
 import static io.f1.backend.domain.user.constants.SessionKeys.USER;
-import static io.f1.backend.domain.user.mapper.UserMapper.toSignupResponse;
 
+import io.f1.backend.domain.auth.dto.CurrentUserAndAdminResponse;
 import io.f1.backend.domain.user.dao.UserRepository;
 import io.f1.backend.domain.user.dto.AuthenticationUser;
 import io.f1.backend.domain.user.dto.SignupRequest;
-import io.f1.backend.domain.user.dto.SignupResponse;
+import io.f1.backend.domain.user.dto.UserPrincipal;
 import io.f1.backend.domain.user.entity.User;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.AuthErrorCode;
+import io.f1.backend.global.exception.errorcode.UserErrorCode;
 import io.f1.backend.global.util.SecurityUtils;
 
 import jakarta.servlet.http.HttpSession;
@@ -25,45 +28,46 @@ public class UserService {
     private final UserRepository userRepository;
 
     @Transactional
-    public SignupResponse signup(HttpSession session, SignupRequest signupRequest) {
+    public CurrentUserAndAdminResponse signup(HttpSession session, SignupRequest signupRequest) {
         AuthenticationUser authenticationUser = extractSessionUser(session);
-
         String nickname = signupRequest.nickname();
-        validateNicknameFormat(nickname);
-        validateNicknameDuplicate(nickname);
+
+        checkNickname(nickname);
 
         User user = initNickname(authenticationUser.userId(), nickname);
         updateSessionAfterSignup(session, user);
+
         SecurityUtils.setAuthentication(user);
+        UserPrincipal userPrincipal = SecurityUtils.getCurrentUserPrincipal();
 
-        return toSignupResponse(user);
+        return CurrentUserAndAdminResponse.from(userPrincipal);
     }
 
     private AuthenticationUser extractSessionUser(HttpSession session) {
         AuthenticationUser authenticationUser =
                 (AuthenticationUser) session.getAttribute(OAUTH_USER);
         if (authenticationUser == null) {
-            throw new RuntimeException("E401001: 로그인이 필요합니다.");
+            throw new CustomException(AuthErrorCode.UNAUTHORIZED);
         }
         return authenticationUser;
     }
 
     private void validateNicknameFormat(String nickname) {
         if (nickname == null || nickname.trim().isEmpty()) {
-            throw new RuntimeException("E400002: 닉네임은 필수 입력입니다.");
+            throw new CustomException(UserErrorCode.NICKNAME_EMPTY);
         }
         if (nickname.length() > 6) {
-            throw new RuntimeException("E400003: 닉네임은 6글자 이하로 입력해야 합니다.");
+            throw new CustomException(UserErrorCode.NICKNAME_TOO_LONG);
         }
         if (!nickname.matches("^[가-힣a-zA-Z0-9]+$")) {
-            throw new RuntimeException("E400004: 한글, 영문, 숫자만 입력해주세요.");
+            throw new CustomException(UserErrorCode.NICKNAME_NOT_ALLOWED);
         }
     }
 
     @Transactional(readOnly = true)
     public void validateNicknameDuplicate(String nickname) {
         if (userRepository.existsUserByNickname(nickname)) {
-            throw new RuntimeException("E409001: 중복된 닉네임입니다.");
+            throw new CustomException(UserErrorCode.NICKNAME_CONFLICT);
         }
     }
 
@@ -72,7 +76,7 @@ public User initNickname(Long userId, String nickname) {
         User user =
                 userRepository
                         .findById(userId)
-                        .orElseThrow(() -> new RuntimeException("E404001: 존재하지 않는 회원입니다."));
+                        .orElseThrow(() -> new CustomException(UserErrorCode.USER_NOT_FOUND));
         user.updateNickname(nickname);
 
         return userRepository.save(user);
@@ -88,17 +92,22 @@ public void deleteUser(Long userId) {
         User user =
                 userRepository
                         .findById(userId)
-                        .orElseThrow(() -> new RuntimeException("E404001: 존재하지 않는 회원입니다."));
+                        .orElseThrow(() -> new CustomException(UserErrorCode.USER_NOT_FOUND));
         userRepository.delete(user);
     }
 
     @Transactional
     public void updateNickname(Long userId, String newNickname, HttpSession session) {
-        validateNicknameFormat(newNickname);
-        validateNicknameDuplicate(newNickname);
+        checkNickname(newNickname);
 
         User user = initNickname(userId, newNickname);
         session.setAttribute(USER, AuthenticationUser.from(user));
         SecurityUtils.setAuthentication(user);
     }
+
+    @Transactional(readOnly = true)
+    public void checkNickname(String nickname) {
+        validateNicknameFormat(nickname);
+        validateNicknameDuplicate(nickname);
+    }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/user/app/handler/CustomAuthenticationEntryPoint.java b/backend/src/main/java/io/f1/backend/domain/user/app/handler/CustomAuthenticationEntryPoint.java
index ebc9ffb1..caa60dd2 100644
--- a/backend/src/main/java/io/f1/backend/domain/user/app/handler/CustomAuthenticationEntryPoint.java
+++ b/backend/src/main/java/io/f1/backend/domain/user/app/handler/CustomAuthenticationEntryPoint.java
@@ -1,17 +1,28 @@
 package io.f1.backend.domain.user.app.handler;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.f1.backend.global.exception.errorcode.AuthErrorCode;
+
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 
+import lombok.RequiredArgsConstructor;
+
 import org.springframework.security.core.AuthenticationException;
 import org.springframework.security.web.AuthenticationEntryPoint;
 import org.springframework.stereotype.Component;
 
 import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
 
 @Component
+@RequiredArgsConstructor
 public class CustomAuthenticationEntryPoint implements AuthenticationEntryPoint {
 
+    private final ObjectMapper objectMapper;
+
     @Override
     public void commence(
             HttpServletRequest request,
@@ -20,6 +31,11 @@ public void commence(
             throws IOException {
         response.setContentType("application/json;charset=UTF-8");
         response.setStatus(HttpServletResponse.SC_UNAUTHORIZED); // 401
-        response.getWriter().write("{\"error\": \"Unauthorized\"}");
+
+        Map<String, String> errorResponse = new HashMap<>();
+        errorResponse.put("code", AuthErrorCode.UNAUTHORIZED.getCode());
+        errorResponse.put("message", AuthErrorCode.UNAUTHORIZED.getMessage());
+
+        objectMapper.writeValue(response.getWriter(), errorResponse);
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/user/app/handler/OAuthSuccessHandler.java b/backend/src/main/java/io/f1/backend/domain/user/app/handler/OAuthSuccessHandler.java
index 37f410f0..085f7644 100644
--- a/backend/src/main/java/io/f1/backend/domain/user/app/handler/OAuthSuccessHandler.java
+++ b/backend/src/main/java/io/f1/backend/domain/user/app/handler/OAuthSuccessHandler.java
@@ -25,9 +25,11 @@ public void onAuthenticationSuccess(
         response.setContentType("application/json;charset=UTF-8");
 
         if (principal.getUserNickname() == null) {
-            getRedirectStrategy().sendRedirect(request, response, "/signup");
+            String SIGNUP_REDIRECT_URL = "http://localhost:3000/signup";
+            getRedirectStrategy().sendRedirect(request, response, SIGNUP_REDIRECT_URL);
         } else {
-            getRedirectStrategy().sendRedirect(request, response, "/room");
+            String MAIN_REDIRECT_URL = "http://localhost:3000/room";
+            getRedirectStrategy().sendRedirect(request, response, MAIN_REDIRECT_URL);
         }
     }
 }
diff --git a/backend/src/main/java/io/f1/backend/domain/user/dto/SignupResponse.java b/backend/src/main/java/io/f1/backend/domain/user/dto/SignupResponse.java
deleted file mode 100644
index afada0fd..00000000
--- a/backend/src/main/java/io/f1/backend/domain/user/dto/SignupResponse.java
+++ /dev/null
@@ -1,3 +0,0 @@
-package io.f1.backend.domain.user.dto;
-
-public record SignupResponse(Long id, String nickname) {}
diff --git a/backend/src/main/java/io/f1/backend/domain/user/mapper/UserMapper.java b/backend/src/main/java/io/f1/backend/domain/user/mapper/UserMapper.java
deleted file mode 100644
index be828638..00000000
--- a/backend/src/main/java/io/f1/backend/domain/user/mapper/UserMapper.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package io.f1.backend.domain.user.mapper;
-
-import io.f1.backend.domain.user.dto.SignupResponse;
-import io.f1.backend.domain.user.entity.User;
-
-public class UserMapper {
-
-    private UserMapper() {}
-
-    public static SignupResponse toSignupResponse(User user) {
-        return new SignupResponse(user.getId(), user.getNickname());
-    }
-}
diff --git a/backend/src/main/java/io/f1/backend/global/config/CorsConfig.java b/backend/src/main/java/io/f1/backend/global/config/CorsConfig.java
index 2b3a4573..3cc2e2aa 100644
--- a/backend/src/main/java/io/f1/backend/global/config/CorsConfig.java
+++ b/backend/src/main/java/io/f1/backend/global/config/CorsConfig.java
@@ -12,7 +12,8 @@ public class CorsConfig {
     public CorsConfigurationSource corsConfigurationSource() {
         CorsConfiguration config = new CorsConfiguration();
 
-        config.addAllowedOriginPattern("*");
+        config.addAllowedOrigin("https://brainrace.duckdns.org");
+
         config.addAllowedHeader("*");
         config.addAllowedMethod("*");
         config.setAllowCredentials(true);
diff --git a/backend/src/main/java/io/f1/backend/global/config/CustomPageableHandlerArgumentResolver.java b/backend/src/main/java/io/f1/backend/global/config/CustomPageableHandlerArgumentResolver.java
new file mode 100644
index 00000000..af25faa1
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/global/config/CustomPageableHandlerArgumentResolver.java
@@ -0,0 +1,45 @@
+package io.f1.backend.global.config;
+
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.CommonErrorCode;
+import io.f1.backend.global.validation.LimitPageSize;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.web.PageableHandlerMethodArgumentResolver;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+public class CustomPageableHandlerArgumentResolver extends PageableHandlerMethodArgumentResolver {
+
+    @Override
+    public Pageable resolveArgument(
+            MethodParameter methodParameter,
+            ModelAndViewContainer mavContainer,
+            NativeWebRequest webRequest,
+            WebDataBinderFactory binderFactory) {
+
+        Pageable pageable =
+                super.resolveArgument(methodParameter, mavContainer, webRequest, binderFactory);
+
+        if (methodParameter.hasMethodAnnotation(LimitPageSize.class)) {
+            LimitPageSize limitPageSize = methodParameter.getMethodAnnotation(LimitPageSize.class);
+            validatePageable(limitPageSize, pageable);
+        }
+
+        return PageRequest.of(
+                oneIndexedPageNumber(pageable.getPageNumber()), pageable.getPageSize());
+    }
+
+    private int oneIndexedPageNumber(int pageNumber) {
+        return pageNumber <= 0 ? 0 : pageNumber - 1;
+    }
+
+    private void validatePageable(LimitPageSize limitPageSize, Pageable pageable) {
+        if (pageable.getPageSize() > limitPageSize.max()) {
+            throw new CustomException(CommonErrorCode.INVALID_PAGINATION);
+        }
+    }
+}
diff --git a/backend/src/main/java/io/f1/backend/global/config/SecurityConfig.java b/backend/src/main/java/io/f1/backend/global/config/SecurityConfig.java
index 26a726da..c6b4680c 100644
--- a/backend/src/main/java/io/f1/backend/global/config/SecurityConfig.java
+++ b/backend/src/main/java/io/f1/backend/global/config/SecurityConfig.java
@@ -11,6 +11,7 @@
 
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpMethod;
 import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -47,6 +48,8 @@ public SecurityFilterChain userFilterChain(HttpSecurity http) throws Exception {
                                                 "/js/**",
                                                 "/admin/login")
                                         .permitAll()
+                                        .requestMatchers(HttpMethod.OPTIONS, "/**")
+                                        .permitAll()
                                         .requestMatchers("/ws/**")
                                         .authenticated()
                                         .requestMatchers("/user/me")
@@ -55,6 +58,10 @@ public SecurityFilterChain userFilterChain(HttpSecurity http) throws Exception {
                                         .hasRole("ADMIN")
                                         .requestMatchers("/auth/me")
                                         .hasAnyRole("USER", "ADMIN")
+                                        .requestMatchers("/quizzes/**")
+                                        .hasAnyRole("USER", "ADMIN")
+                                        .requestMatchers("/questions/**")
+                                        .hasAnyRole("USER", "ADMIN")
                                         .anyRequest()
                                         .authenticated())
                 .formLogin(
diff --git a/backend/src/main/java/io/f1/backend/global/config/WebConfig.java b/backend/src/main/java/io/f1/backend/global/config/WebConfig.java
index a80ae64c..1fb6747c 100644
--- a/backend/src/main/java/io/f1/backend/global/config/WebConfig.java
+++ b/backend/src/main/java/io/f1/backend/global/config/WebConfig.java
@@ -3,9 +3,12 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.filter.HiddenHttpMethodFilter;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
+import java.util.List;
+
 @Configuration
 public class WebConfig implements WebMvcConfigurer {
 
@@ -17,6 +20,11 @@ public void addResourceHandlers(ResourceHandlerRegistry registry) {
                 .addResourceLocations("file:images/thumbnail/");
     }
 
+    @Override
+    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+        resolvers.add(new CustomPageableHandlerArgumentResolver());
+    }
+
     @Bean
     public HiddenHttpMethodFilter hiddenHttpMethodFilter() {
         return new HiddenHttpMethodFilter();
diff --git a/backend/src/main/java/io/f1/backend/global/config/WebSocketConfig.java b/backend/src/main/java/io/f1/backend/global/config/WebSocketConfig.java
index 910e3b83..cb229ed4 100644
--- a/backend/src/main/java/io/f1/backend/global/config/WebSocketConfig.java
+++ b/backend/src/main/java/io/f1/backend/global/config/WebSocketConfig.java
@@ -8,6 +8,7 @@
 import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
 import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
 import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
+import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
 
 @Configuration
 @RequiredArgsConstructor
@@ -18,7 +19,9 @@ public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
 
     @Override
     public void registerStompEndpoints(StompEndpointRegistry registry) {
-        registry.addEndpoint("/ws/game-room").setAllowedOriginPatterns("*");
+        registry.addEndpoint("/ws/game-room")
+                .addInterceptors(new HttpSessionHandshakeInterceptor())
+                .setAllowedOriginPatterns("*");
     }
 
     @Override
diff --git a/backend/src/main/java/io/f1/backend/global/exception/errorcode/AdminErrorCode.java b/backend/src/main/java/io/f1/backend/global/exception/errorcode/AdminErrorCode.java
new file mode 100644
index 00000000..5d7dc260
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/global/exception/errorcode/AdminErrorCode.java
@@ -0,0 +1,18 @@
+package io.f1.backend.global.exception.errorcode;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.http.HttpStatus;
+
+@Getter
+@RequiredArgsConstructor
+public enum AdminErrorCode implements ErrorCode {
+    ADMIN_NOT_FOUND("E404007", HttpStatus.NOT_FOUND, "존재하지 않는 관리자 입니다");
+
+    private final String code;
+
+    private final HttpStatus httpStatus;
+
+    private final String message;
+}
diff --git a/backend/src/main/java/io/f1/backend/global/exception/errorcode/GameErrorCode.java b/backend/src/main/java/io/f1/backend/global/exception/errorcode/GameErrorCode.java
new file mode 100644
index 00000000..73a12122
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/global/exception/errorcode/GameErrorCode.java
@@ -0,0 +1,18 @@
+package io.f1.backend.global.exception.errorcode;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import org.springframework.http.HttpStatus;
+
+@Getter
+@RequiredArgsConstructor
+public enum GameErrorCode implements ErrorCode {
+    GAME_SETTING_CONFLICT("E409002", HttpStatus.CONFLICT, "게임 설정이 맞지 않습니다.");
+
+    private final String code;
+
+    private final HttpStatus httpStatus;
+
+    private final String message;
+}
diff --git a/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuestionErrorCode.java b/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuestionErrorCode.java
index 9b7c0c1e..7a179950 100644
--- a/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuestionErrorCode.java
+++ b/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuestionErrorCode.java
@@ -8,6 +8,8 @@
 @Getter
 @RequiredArgsConstructor
 public enum QuestionErrorCode implements ErrorCode {
+    INVALID_CONTENT_LENGTH("E400011", HttpStatus.BAD_REQUEST, "문제는 5자 이상 30자 이하로 입력해주세요."),
+    INVALID_ANSWER_LENGTH("E400012", HttpStatus.BAD_REQUEST, "정답은 1자 이상 30자 이하로 입력해주세요."),
     QUESTION_NOT_FOUND("E404003", HttpStatus.NOT_FOUND, "존재하지 않는 문제입니다.");
 
     private final String code;
diff --git a/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuizErrorCode.java b/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuizErrorCode.java
index e03983b1..fbedd44c 100644
--- a/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuizErrorCode.java
+++ b/backend/src/main/java/io/f1/backend/global/exception/errorcode/QuizErrorCode.java
@@ -9,9 +9,15 @@
 @RequiredArgsConstructor
 public enum QuizErrorCode implements ErrorCode {
     FILE_SIZE_TOO_LARGE("E400005", HttpStatus.BAD_REQUEST, "파일 크기가 너무 큽니다."),
+    INVALID_TITLE_LENGTH("E400009", HttpStatus.BAD_REQUEST, "제목은 2자 이상 30자 이하로 입력해주세요."),
+    INVALID_DESC_LENGTH("E400010", HttpStatus.BAD_REQUEST, "설명은 10자 이상 50자 이하로 입력해주세요."),
+    UNSUPPORTED_IMAGE_FORMAT(
+            "E400013", HttpStatus.BAD_REQUEST, "지원하지 않는 이미지 형식입니다. (jpg, jpeg, png, webp 만 가능)"),
     UNSUPPORTED_MEDIA_TYPE("E415001", HttpStatus.UNSUPPORTED_MEDIA_TYPE, "지원하지 않는 파일 형식입니다."),
     INVALID_FILTER("E400007", HttpStatus.BAD_REQUEST, "title 또는 creator 중 하나만 입력 가능합니다."),
-    QUIZ_NOT_FOUND("E404002", HttpStatus.NOT_FOUND, "존재하지 않는 퀴즈입니다.");
+    QUIZ_NOT_FOUND("E404002", HttpStatus.NOT_FOUND, "존재하지 않는 퀴즈입니다."),
+    THUMBNAIL_SAVE_FAILED("E500002", HttpStatus.INTERNAL_SERVER_ERROR, "썸네일 저장에 실패했습니다."),
+    THUMBNAIL_DELETE_FAILED("E500003", HttpStatus.INTERNAL_SERVER_ERROR, "썸네일 삭제에 실패했습니다.");
 
     private final String code;
 
diff --git a/backend/src/main/java/io/f1/backend/global/exception/errorcode/RoomErrorCode.java b/backend/src/main/java/io/f1/backend/global/exception/errorcode/RoomErrorCode.java
index 0626fab0..2925373e 100644
--- a/backend/src/main/java/io/f1/backend/global/exception/errorcode/RoomErrorCode.java
+++ b/backend/src/main/java/io/f1/backend/global/exception/errorcode/RoomErrorCode.java
@@ -10,8 +10,10 @@
 public enum RoomErrorCode implements ErrorCode {
     ROOM_USER_LIMIT_REACHED("E403002", HttpStatus.FORBIDDEN, "정원이 모두 찼습니다."),
     ROOM_GAME_IN_PROGRESS("E403003", HttpStatus.FORBIDDEN, "게임이 진행 중 입니다."),
+    PLAYER_NOT_READY("E403004", HttpStatus.FORBIDDEN, "게임 시작을 위한 준비 상태가 아닙니다."),
     ROOM_NOT_FOUND("E404005", HttpStatus.NOT_FOUND, "존재하지 않는 방입니다."),
     WRONG_PASSWORD("E401006", HttpStatus.UNAUTHORIZED, "비밀번호가 일치하지않습니다."),
+    PLAYER_NOT_FOUND("E404007", HttpStatus.NOT_FOUND, "존재하지 않는 플레이어입니다."),
     SOCKET_SESSION_NOT_FOUND("E404006", HttpStatus.NOT_FOUND, "존재하지 않는 소켓 세션입니다.");
 
     private final String code;
diff --git a/backend/src/main/java/io/f1/backend/global/util/SecurityUtils.java b/backend/src/main/java/io/f1/backend/global/util/SecurityUtils.java
index 2735545a..96e2b316 100644
--- a/backend/src/main/java/io/f1/backend/global/util/SecurityUtils.java
+++ b/backend/src/main/java/io/f1/backend/global/util/SecurityUtils.java
@@ -3,6 +3,8 @@
 import io.f1.backend.domain.admin.dto.AdminPrincipal;
 import io.f1.backend.domain.user.dto.UserPrincipal;
 import io.f1.backend.domain.user.entity.User;
+import io.f1.backend.global.exception.CustomException;
+import io.f1.backend.global.exception.errorcode.AuthErrorCode;
 
 import jakarta.servlet.http.HttpSession;
 
@@ -25,7 +27,7 @@ public static void setAuthentication(User user) {
     }
 
     public static UserPrincipal getCurrentUserPrincipal() {
-        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+        Authentication authentication = getAuthentication();
         if (authentication != null
                 && authentication.getPrincipal() instanceof UserPrincipal userPrincipal) {
             return userPrincipal;
@@ -53,12 +55,12 @@ private static void clearAuthentication() {
     }
 
     public static AdminPrincipal getCurrentAdminPrincipal() {
-        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+        Authentication authentication = getAuthentication();
         if (authentication != null
                 && authentication.getPrincipal() instanceof AdminPrincipal adminPrincipal) {
             return adminPrincipal;
         }
-        throw new RuntimeException("E401001: 로그인이 필요합니다.");
+        throw new CustomException(AuthErrorCode.UNAUTHORIZED);
     }
 
     public static Authentication getAuthentication() {
diff --git a/backend/src/main/java/io/f1/backend/global/validation/LimitPageSize.java b/backend/src/main/java/io/f1/backend/global/validation/LimitPageSize.java
new file mode 100644
index 00000000..38ad0f68
--- /dev/null
+++ b/backend/src/main/java/io/f1/backend/global/validation/LimitPageSize.java
@@ -0,0 +1,14 @@
+package io.f1.backend.global.validation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Documented
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface LimitPageSize {
+    int max() default 100;
+}
diff --git a/backend/src/main/resources/application.yml b/backend/src/main/resources/application.yml
index 4fe7ef60..711788eb 100644
--- a/backend/src/main/resources/application.yml
+++ b/backend/src/main/resources/application.yml
@@ -1,4 +1,8 @@
 spring:
+  servlet:
+    multipart:
+      max-file-size: 5MB
+
   config:
     import: optional:file:.env[.properties]
 
@@ -12,11 +16,11 @@ spring:
     username: ${DB_USERNAME}
     password: ${DB_PASSWORD}
 
-#  Redis 도입 시 정의
-#  data:
-#    redis:
-#      host: ${REDIS_HOST}
-#      port: ${REDIS_PORT}
+  #  Redis 도입 시 정의
+  #  data:
+  #    redis:
+  #      host: ${REDIS_HOST}
+  #      port: ${REDIS_PORT}
 
   jpa:
     defer-datasource-initialization: true # 현재는 data.sql 에서 더미 유저 자동 추가를 위해 넣어뒀음.
@@ -48,5 +52,14 @@ spring:
             user-name-attribute: id
 
 file:
-  thumbnail-path : images/thumbnail/ # 이후 배포 환경에서는 바꾸면 될 듯
+  thumbnail-path: images/thumbnail/ # 이후 배포 환경에서는 바꾸면 될 듯
   default-thumbnail-url: /images/thumbnail/default.png
+
+server:
+  servlet:
+    session:
+      cookie:
+        same-site: None
+        secure: true
+        http-only: true
+      timeout: 60
\ No newline at end of file
diff --git a/backend/src/main/resources/data.sql b/backend/src/main/resources/data.sql
index 015cab81..db9171aa 100644
--- a/backend/src/main/resources/data.sql
+++ b/backend/src/main/resources/data.sql
@@ -1,2 +1,40 @@
 INSERT INTO user (id, nickname, provider, provider_id, last_login)
 VALUES (1, 'test-user', 'kakao', 'kakao-1234', NOW());
+
+
+INSERT INTO quiz (title,
+                  description,
+                  quiz_type,
+                  thumbnail_url,
+                  creator_id)
+VALUES ('기본 상식 퀴즈',
+        '일반 상식을 테스트하는 쉬운 퀴즈입니다.',
+        'TEXT',
+        'https://picsum.photos/200/300',
+        1);
+
+INSERT INTO question (quiz_id, answer, created_at, updated_at)
+VALUES
+    (1, '정답1', NOW(), NOW()),
+    (1, '정답2', NOW(), NOW()),
+    (1, '정답3', NOW(), NOW()),
+    (1, '정답4', NOW(), NOW()),
+    (1, '정답5', NOW(), NOW()),
+    (1, '정답6', NOW(), NOW()),
+    (1, '정답7', NOW(), NOW()),
+    (1, '정답8', NOW(), NOW()),
+    (1, '정답9', NOW(), NOW()),
+    (1, '정답10', NOW(), NOW());
+
+INSERT INTO text_question (question_id, content)
+VALUES
+    (1, '1번 문제 내용입니다.'),
+    (2, '2번 문제 내용입니다.'),
+    (3, '3번 문제 내용입니다.'),
+    (4, '4번 문제 내용입니다.'),
+    (5, '5번 문제 내용입니다.'),
+    (6, '6번 문제 내용입니다.'),
+    (7, '7번 문제 내용입니다.'),
+    (8, '8번 문제 내용입니다.'),
+    (9, '9번 문제 내용입니다.'),
+    (10, '10번 문제 내용입니다.');
\ No newline at end of file
diff --git a/backend/src/test/java/io/f1/backend/domain/game/app/RoomServiceTests.java b/backend/src/test/java/io/f1/backend/domain/game/app/RoomServiceTests.java
index 2c9df079..dbe01b8f 100644
--- a/backend/src/test/java/io/f1/backend/domain/game/app/RoomServiceTests.java
+++ b/backend/src/test/java/io/f1/backend/domain/game/app/RoomServiceTests.java
@@ -11,6 +11,7 @@
 import io.f1.backend.domain.game.model.RoomSetting;
 import io.f1.backend.domain.game.store.RoomRepository;
 import io.f1.backend.domain.quiz.app.QuizService;
+import io.f1.backend.domain.user.dto.UserPrincipal;
 import io.f1.backend.domain.user.entity.User;
 import io.f1.backend.global.util.SecurityUtils;
 
@@ -29,6 +30,7 @@
 
 import java.time.LocalDateTime;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CountDownLatch;
@@ -142,9 +144,11 @@ void exitRoom_synchronized() throws Exception {
             executorService.submit(
                     () -> {
                         try {
+                            UserPrincipal principal =
+                                    new UserPrincipal(user, Collections.emptyMap());
                             SecurityUtils.setAuthentication(user);
                             log.info("room.getHost().getId() = {}", room.getHost().getId());
-                            roomService.exitRoom(roomId, sessionId);
+                            roomService.exitRoom(roomId, sessionId, principal);
                         } catch (Exception e) {
                             e.printStackTrace();
                         } finally {
diff --git a/backend/src/test/java/io/f1/backend/domain/stat/StatBrowserTest.java b/backend/src/test/java/io/f1/backend/domain/stat/StatBrowserTest.java
new file mode 100644
index 00000000..e3af6120
--- /dev/null
+++ b/backend/src/test/java/io/f1/backend/domain/stat/StatBrowserTest.java
@@ -0,0 +1,89 @@
+package io.f1.backend.domain.stat;
+
+import static io.f1.backend.global.exception.errorcode.CommonErrorCode.INVALID_PAGINATION;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import com.github.database.rider.core.api.dataset.DataSet;
+
+import io.f1.backend.global.template.BrowserTestTemplate;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.security.test.context.support.WithMockUser;
+import org.springframework.test.web.servlet.ResultActions;
+
+@WithMockUser
+public class StatBrowserTest extends BrowserTestTemplate {
+    @Test
+    @DataSet("datasets/stat/one-user-stat.yml")
+    @DisplayName("총 유저 수가 1명이면 첫 페이지에서 1개의 결과를 반환한다")
+    void totalRankingForSingleUser() throws Exception {
+        // when
+        ResultActions result = mockMvc.perform(get("/stats/rankings"));
+
+        // then
+        result.andExpectAll(
+                status().isOk(),
+                jsonPath("$.totalPages").value(1),
+                jsonPath("$.currentPage").value(1),
+                jsonPath("$.totalElements").value(1),
+                jsonPath("$.ranks.length()").value(1));
+    }
+
+    @Test
+    @DisplayName("100을 넘는 페이지 크기 요청이 오면 예외를 발생시킨다")
+    void totalRankingForSingleUserWithInvalidPageSize() throws Exception {
+        // when
+        ResultActions result = mockMvc.perform(get("/stats/rankings").param("size", "101"));
+
+        // then
+        result.andExpectAll(
+                status().isBadRequest(), jsonPath("$.code").value(INVALID_PAGINATION.getCode()));
+    }
+
+    @Test
+    @DataSet("datasets/stat/three-user-stat.yml")
+    @DisplayName("총 유저 수가 3명이면 첫 페이지에서 3개의 결과를 반환한다")
+    void totalRankingForThreeUser() throws Exception {
+        // when
+        ResultActions result = mockMvc.perform(get("/stats/rankings"));
+
+        // then
+        result.andExpectAll(
+                status().isOk(),
+                jsonPath("$.totalPages").value(1),
+                jsonPath("$.currentPage").value(1),
+                jsonPath("$.totalElements").value(3),
+                jsonPath("$.ranks.length()").value(3));
+    }
+
+    @Test
+    @DataSet("datasets/stat/three-user-stat.yml")
+    @DisplayName("총 유저 수가 3명일 때 페이지 크기가 2이면, 첫 페이지에서 2개, 두 번째 페이지에 1개의 결과를 반환한다")
+    void totalRankingForThreeUserWithPageSize2() throws Exception {
+        // when
+        ResultActions resultPage1 =
+                mockMvc.perform(get("/stats/rankings").param("page", "1").param("size", "2"));
+
+        ResultActions resultPage2 =
+                mockMvc.perform(get("/stats/rankings").param("page", "2").param("size", "2"));
+
+        // then
+        resultPage1.andExpectAll(
+                status().isOk(),
+                jsonPath("$.totalPages").value(2),
+                jsonPath("$.currentPage").value(1),
+                jsonPath("$.totalElements").value(2),
+                jsonPath("$.ranks.length()").value(2));
+
+        resultPage2.andExpectAll(
+                status().isOk(),
+                jsonPath("$.totalPages").value(2),
+                jsonPath("$.currentPage").value(2),
+                jsonPath("$.totalElements").value(1),
+                jsonPath("$.ranks.length()").value(1));
+    }
+}
diff --git a/backend/src/test/java/io/f1/backend/global/config/TestPhysicalNamingStrategy.java b/backend/src/test/java/io/f1/backend/global/config/TestPhysicalNamingStrategy.java
new file mode 100644
index 00000000..68effff3
--- /dev/null
+++ b/backend/src/test/java/io/f1/backend/global/config/TestPhysicalNamingStrategy.java
@@ -0,0 +1,20 @@
+package io.f1.backend.global.config;
+
+import org.hibernate.boot.model.naming.CamelCaseToUnderscoresNamingStrategy;
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+
+public class TestPhysicalNamingStrategy extends CamelCaseToUnderscoresNamingStrategy {
+
+    @Override
+    public Identifier toPhysicalTableName(Identifier name, JdbcEnvironment context) {
+        if (name == null) return null;
+
+        String tableName = name.getText();
+        if ("user".equalsIgnoreCase(tableName)) {
+            return Identifier.toIdentifier("user_test");
+        }
+
+        return super.toPhysicalTableName(name, context);
+    }
+}
diff --git a/backend/src/test/java/io/f1/backend/global/template/BrowserTestTemplate.java b/backend/src/test/java/io/f1/backend/global/template/BrowserTestTemplate.java
new file mode 100644
index 00000000..061ff7ef
--- /dev/null
+++ b/backend/src/test/java/io/f1/backend/global/template/BrowserTestTemplate.java
@@ -0,0 +1,15 @@
+package io.f1.backend.global.template;
+
+import com.github.database.rider.spring.api.DBRider;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.web.servlet.MockMvc;
+
+@DBRider
+@SpringBootTest
+@AutoConfigureMockMvc
+public abstract class BrowserTestTemplate {
+    @Autowired protected MockMvc mockMvc;
+}
diff --git a/backend/src/test/resources/application.yml b/backend/src/test/resources/application.yml
index c7b6b358..215917fd 100644
--- a/backend/src/test/resources/application.yml
+++ b/backend/src/test/resources/application.yml
@@ -1,9 +1,15 @@
 spring:
   datasource:
-    url: jdbc:h2:mem:testdb;MODE=MYSQL
+    url: jdbc:h2:mem:testdb;MODE=MYSQL;DATABASE_TO_LOWER=TRUE
     username: sa
     password:
 
+  jpa:
+    hibernate:
+      ddl-auto: create
+      naming:
+        physical-strategy: io.f1.backend.global.config.TestPhysicalNamingStrategy
+
   sql:
     init:
       mode: never
diff --git a/backend/src/test/resources/datasets/stat.yml b/backend/src/test/resources/datasets/stat.yml
new file mode 100644
index 00000000..85e9e7ee
--- /dev/null
+++ b/backend/src/test/resources/datasets/stat.yml
@@ -0,0 +1,18 @@
+stat:
+  - id: 1
+    user_id: 1
+    total_games: 100
+    winning_games: 100
+    score: 1000
+
+  - id: 2
+    user_id: 2
+    total_games: 20
+    winning_games: 20
+    score: 200
+
+  - id: 3
+    user_id: 3
+    total_games: 30
+    winning_games: 30
+    score: 300
\ No newline at end of file
diff --git a/backend/src/test/resources/datasets/stat/one-user-stat.yml b/backend/src/test/resources/datasets/stat/one-user-stat.yml
new file mode 100644
index 00000000..a9941d61
--- /dev/null
+++ b/backend/src/test/resources/datasets/stat/one-user-stat.yml
@@ -0,0 +1,13 @@
+user_test:
+  - id: 1
+    nickname: "USER1"
+    provider: "kakao"
+    provider_id: "kakao1"
+    last_login: 2025-07-17 10:00:00
+
+stat:
+  - id: 1
+    user_id: 1
+    total_games: 10
+    winning_games: 10
+    score: 100
\ No newline at end of file
diff --git a/backend/src/test/resources/datasets/stat/three-user-stat.yml b/backend/src/test/resources/datasets/stat/three-user-stat.yml
new file mode 100644
index 00000000..ab5071a7
--- /dev/null
+++ b/backend/src/test/resources/datasets/stat/three-user-stat.yml
@@ -0,0 +1,33 @@
+user_test:
+  - id: 1
+    nickname: "USER1"
+    provider: "kakao"
+    provider_id: "kakao1"
+    last_login: 2025-07-17 10:00:00
+  - id: 2
+    nickname: "USER2"
+    provider: "kakao"
+    provider_id: "kakao2"
+    last_login: 2025-07-17 10:00:00
+  - id: 3
+    nickname: "USER3"
+    provider: "kakao"
+    provider_id: "kakao3"
+    last_login: 2025-07-17 10:00:00
+
+stat:
+  - id: 1
+    user_id: 1
+    total_games: 10
+    winning_games: 10
+    score: 100
+  - id: 2
+    user_id: 2
+    total_games: 20
+    winning_games: 20
+    score: 200
+  - id: 3
+    user_id: 3
+    total_games: 30
+    winning_games: 30
+    score: 300
\ No newline at end of file
diff --git a/backend/src/test/resources/datasets/user.yml b/backend/src/test/resources/datasets/user.yml
new file mode 100644
index 00000000..22ed1f25
--- /dev/null
+++ b/backend/src/test/resources/datasets/user.yml
@@ -0,0 +1,18 @@
+user_test:
+  - id: 1
+    nickname: "USER1"
+    provider: "kakao"
+    provider_id: "kakao1"
+    last_login: 2025-07-17 10:00:00
+
+  - id: 2
+    nickname: "USER2"
+    provider: "kakao"
+    provider_id: "kakao2"
+    last_login: 2025-07-17 10:00:00
+
+  - id: 3
+    nickname: "USER3"
+    provider: "kakao"
+    provider_id: "kakao3"
+    last_login: 2025-07-17 10:00:00
\ No newline at end of file
diff --git a/backend/src/test/resources/dbunit.yml b/backend/src/test/resources/dbunit.yml
new file mode 100644
index 00000000..a52c7928
--- /dev/null
+++ b/backend/src/test/resources/dbunit.yml
@@ -0,0 +1,3 @@
+caseInsensitiveStrategy: LOWERCASE
+alwaysCleanBefore: true
+alwaysCleanAfter: true