From 94073cec75922319b5b83e6716b871bedba5db98 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 16:31:24 +0900
Subject: [PATCH 01/14] =?UTF-8?q?docs:=20=EA=B8=B0=EB=8A=A5=EB=AA=A9?=
 =?UTF-8?q?=EB=A1=9D=20=EC=9E=91=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 8d7e8aee..7282e598 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,27 @@
-# java-baseball-precourse
\ No newline at end of file
+# java-baseball-precourse
+
+### 문제
+- 기본적으로 1부터 9까지 서로 다른 수로 이루어진 3자리의 수를 맞추는 게임이다.
+- 같은 수가 같은 자리에 있으면 스트라이크, 다른 자리에 있으면 볼, 같은 수가 전혀 없으면 포볼 또는 낫싱이란 힌트를
+얻고, 그 힌트를 이용해서 먼저 상대방(컴퓨터)의 수를 맞추면 승리한다.
+  - [예] 상대방(컴퓨터)의 수가 425일 때, 123을 제시한 경우 : 1스트라이크, 456을 제시한 경우 : 1스트라이크 1볼,
+  789를 제시한 경우 : 낫싱
+- 위 숫자 야구게임에서 상대방의 역할을 컴퓨터가 한다. 컴퓨터는 1에서 9까지 서로 다른 임의의 수 3개를 선택한다. 게임 플레이어는 컴퓨터가 생각하고 있는 3개의 숫자를 입력하고, 컴퓨터는 입력한 숫자에 대한 결과를 출력한다.
+- 이 같은 과정을 반복해 컴퓨터가 선택한 3개의 숫자를 모두 맞히면 게임이 종료된다.
+- 게임을 종료한 후 게임을 다시 시작하거나 완전히 종료할 수 있다.
+- 사용자가 잘못된 값을 입력할 경우 [ERROR]로 시작하는 에러 메시지를 출력하고 게임을 계속 진행할 수 있어야
+
+### 구조
+- 입력기 (controller)
+- 출력기 (view)
+- baseball 판독기 (model)
+- baseball 정답 생성기 (model)
+- baseball 게임 진행 (model)
+- 에러 핸들러
+
+### 기능 요구사항
+- [ ] baseball 정답 생성
+- [ ] baseball 정답 판독
+- [ ] baseball 게임 판단
+- [ ] 입력기
+- [ ] 출력기

From cfcee2536c899104012709f3ffef4d22edd0487a Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 16:42:41 +0900
Subject: [PATCH 02/14] =?UTF-8?q?docs:=20=EA=B8=B0=EB=8A=A5=20=EC=84=B8?=
 =?UTF-8?q?=EB=B6=80=EC=82=AC=ED=95=AD=20=EC=9E=91=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 7282e598..95f977f8 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,15 @@
 
 ### 기능 요구사항
 - [ ] baseball 정답 생성
-- [ ] baseball 정답 판독
+  - [ ] 1부터 9까지의 다른 수로 이루어진 3자리의 수를 생성합니다.
+- [ ] baseball 정답 판독 
+  - [ ] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 올립니다.
+  - [ ] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
+  - [ ] strike or ball의 카운트가 0이 아닌 경우 출력하고, 모두 0인 경우 `낫싱`을 출력합니다.
 - [ ] baseball 게임 판단
+  - [ ] 정답 판독기에서 판독한 값이 3스트라이크일 경우 출력하고 `3개의 숫자를 모두 맞히셨습니다! 게임 끝` 멘트와 게임을 종료합니다.
+  - [ ] 게임이 시작된 상황이라면 숫자를 입력 받고 판독 결과를 반환합니다.
+  - [ ] 게임이 진행중이 아니라면 1의 입력의 경우 정답 생성을 요청하고, 숫자 입력을 요구합니다.
+  - [ ] 게임이 진행중이 아니라면 2의 입력의 경우 게임을 종료합니다.
 - [ ] 입력기
 - [ ] 출력기

From 50b14c231e36d268dee941c5f414e51c9ad91468 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 17:32:42 +0900
Subject: [PATCH 03/14] =?UTF-8?q?feat:=20=EC=88=AB=EC=9E=90=EC=95=BC?=
 =?UTF-8?q?=EA=B5=AC=20=EC=A0=95=EB=8B=B5=20=EC=83=9D=EC=84=B1=EB=A1=9C?=
 =?UTF-8?q?=EC=A7=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                                     |  7 +--
 src/main/java/model/AnswerGenerator.java      |  7 +++
 .../java/model/BaseballAnswerGenerator.java   | 24 ++++++++++
 .../java/BaseballAnswerGeneratorTest.java     | 46 +++++++++++++++++++
 4 files changed, 81 insertions(+), 3 deletions(-)
 create mode 100644 src/main/java/model/AnswerGenerator.java
 create mode 100644 src/main/java/model/BaseballAnswerGenerator.java
 create mode 100644 src/test/java/BaseballAnswerGeneratorTest.java

diff --git a/README.md b/README.md
index 95f977f8..74493e8b 100644
--- a/README.md
+++ b/README.md
@@ -20,9 +20,10 @@
 - 에러 핸들러
 
 ### 기능 요구사항
-- [ ] baseball 정답 생성
-  - [ ] 1부터 9까지의 다른 수로 이루어진 3자리의 수를 생성합니다.
-- [ ] baseball 정답 판독 
+- [X] baseball 정답 생성
+  - [X] 1부터 9까지의 다른 수로 이루어진 3자리의 수를 생성합니다.
+    - 제약 사항: 1부터 9까지만, 정답 길이 3
+- [ ] baseball 정답 판독
   - [ ] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 올립니다.
   - [ ] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
   - [ ] strike or ball의 카운트가 0이 아닌 경우 출력하고, 모두 0인 경우 `낫싱`을 출력합니다.
diff --git a/src/main/java/model/AnswerGenerator.java b/src/main/java/model/AnswerGenerator.java
new file mode 100644
index 00000000..23f1d3c7
--- /dev/null
+++ b/src/main/java/model/AnswerGenerator.java
@@ -0,0 +1,7 @@
+package model;
+
+public interface AnswerGenerator {
+
+    public String generateAnswer();
+
+}
diff --git a/src/main/java/model/BaseballAnswerGenerator.java b/src/main/java/model/BaseballAnswerGenerator.java
new file mode 100644
index 00000000..ae5ae9c0
--- /dev/null
+++ b/src/main/java/model/BaseballAnswerGenerator.java
@@ -0,0 +1,24 @@
+package model;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class BaseballAnswerGenerator implements AnswerGenerator{
+
+    @Override
+    public String generateAnswer() {
+        Set<Integer> numbers = new HashSet<>();
+
+        while (numbers.size() < 3) {
+            numbers.add(ThreadLocalRandom.current().nextInt(1, 10));
+        }
+
+        StringBuilder answer = new StringBuilder();
+        for (int n : numbers) {
+            answer.append(n);
+        }
+
+        return answer.toString();
+    }
+}
diff --git a/src/test/java/BaseballAnswerGeneratorTest.java b/src/test/java/BaseballAnswerGeneratorTest.java
new file mode 100644
index 00000000..330e8faa
--- /dev/null
+++ b/src/test/java/BaseballAnswerGeneratorTest.java
@@ -0,0 +1,46 @@
+import model.AnswerGenerator;
+import model.BaseballAnswerGenerator;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BaseballAnswerGeneratorTest {
+
+    private AnswerGenerator answerGenerator;
+
+    @BeforeEach
+    void setup() {
+        answerGenerator = new BaseballAnswerGenerator();
+    }
+
+    @DisplayName("정답 길이 테스트")
+    @Test
+    void generatedLengthTest() {
+        String answer = answerGenerator.generateAnswer();
+        assertThat(answer.length()).isSameAs(3);
+    }
+
+    @DisplayName("정답 안에 0이 없는지 test")
+    @Test
+    void generatedAnswerZeroTest() {
+        String answer = answerGenerator.generateAnswer();
+        assertThat(answer).doesNotContain("0");
+    }
+
+    @DisplayName("정답이 모두 숫자인지 test")
+    @Test
+    void generatedAnswerAsciiTest() {
+        String answer = answerGenerator.generateAnswer();
+        assertThat(answer).matches("\\d+");
+    }
+
+    @DisplayName("정답이 숫자가 모두 다른지 test")
+    @Test
+    void generatedAnswerDiffTest() {
+        String answer = answerGenerator.generateAnswer();
+        assertThat(answer.chars().distinct().count()).isEqualTo(answer.length());
+    }
+
+}

From cd798dc46fbb70d4fbcaa20dfac33fb26d95a0aa Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 18:01:36 +0900
Subject: [PATCH 04/14] =?UTF-8?q?refactor:=20=ED=85=8C=EC=8A=A4=ED=8A=B8?=
 =?UTF-8?q?=20=EB=84=A4=EC=9D=B4=EB=B0=8D=20=EB=A6=AC=ED=8E=99=ED=86=A0?=
 =?UTF-8?q?=EB=A7=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/BaseballAnswerGeneratorTest.java     | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/test/java/BaseballAnswerGeneratorTest.java b/src/test/java/BaseballAnswerGeneratorTest.java
index 330e8faa..f1fe8e33 100644
--- a/src/test/java/BaseballAnswerGeneratorTest.java
+++ b/src/test/java/BaseballAnswerGeneratorTest.java
@@ -15,32 +15,32 @@ void setup() {
         answerGenerator = new BaseballAnswerGenerator();
     }
 
-    @DisplayName("정답 길이 테스트")
+    @DisplayName("정답은 3자리 숫자이다")
     @Test
-    void generatedLengthTest() {
+    void generateAnswer_returnsLengthThree() {
         String answer = answerGenerator.generateAnswer();
-        assertThat(answer.length()).isSameAs(3);
+        assertThat(answer.length()).isEqualTo(3);
     }
 
-    @DisplayName("정답 안에 0이 없는지 test")
+    @DisplayName("정답은 0을 포함하지 않는다")
     @Test
-    void generatedAnswerZeroTest() {
+    void generateAnswer_doesNotContainZero() {
         String answer = answerGenerator.generateAnswer();
         assertThat(answer).doesNotContain("0");
     }
 
-    @DisplayName("정답이 모두 숫자인지 test")
+    @DisplayName("정답은 숫자로만 이루어져 있다")
     @Test
-    void generatedAnswerAsciiTest() {
+    void generateAnswer_containsOnlyDigits() {
         String answer = answerGenerator.generateAnswer();
         assertThat(answer).matches("\\d+");
     }
 
-    @DisplayName("정답이 숫자가 모두 다른지 test")
+    @DisplayName("정답의 모든 숫자는 서로 다르다")
     @Test
-    void generatedAnswerDiffTest() {
+    void generateAnswer_hasNoDuplicateDigits() {
         String answer = answerGenerator.generateAnswer();
-        assertThat(answer.chars().distinct().count()).isEqualTo(answer.length());
+        assertThat(answer.chars().distinct().count())
+                .isEqualTo(answer.length());
     }
-
 }

From 4986b5a635b5f16577853983b8a4dc134fb99267 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 18:10:29 +0900
Subject: [PATCH 05/14] =?UTF-8?q?feat:=20=EC=8A=A4=ED=8A=B8=EB=9D=BC?=
 =?UTF-8?q?=EC=9D=B4=ED=81=AC=20=EA=B0=9C=EC=88=98=20=ED=8C=90=EB=B3=84=20?=
 =?UTF-8?q?=EB=A1=9C=EC=A7=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                                    |  2 +-
 src/main/java/model/AnswerJudge.java         |  7 ++++
 src/main/java/model/BaseballAnswerJudge.java | 13 +++++++
 src/test/java/BaseballAnswerJudgeTest.java   | 38 ++++++++++++++++++++
 4 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/model/AnswerJudge.java
 create mode 100644 src/main/java/model/BaseballAnswerJudge.java
 create mode 100644 src/test/java/BaseballAnswerJudgeTest.java

diff --git a/README.md b/README.md
index 74493e8b..ce6af43e 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@
   - [X] 1부터 9까지의 다른 수로 이루어진 3자리의 수를 생성합니다.
     - 제약 사항: 1부터 9까지만, 정답 길이 3
 - [ ] baseball 정답 판독
-  - [ ] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 올립니다.
+  - [X] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 반환합니다.
   - [ ] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
   - [ ] strike or ball의 카운트가 0이 아닌 경우 출력하고, 모두 0인 경우 `낫싱`을 출력합니다.
 - [ ] baseball 게임 판단
diff --git a/src/main/java/model/AnswerJudge.java b/src/main/java/model/AnswerJudge.java
new file mode 100644
index 00000000..c6919dee
--- /dev/null
+++ b/src/main/java/model/AnswerJudge.java
@@ -0,0 +1,7 @@
+package model;
+
+public interface AnswerJudge {
+
+    public Integer countStrikes(String input, String answer);
+
+}
diff --git a/src/main/java/model/BaseballAnswerJudge.java b/src/main/java/model/BaseballAnswerJudge.java
new file mode 100644
index 00000000..580ca608
--- /dev/null
+++ b/src/main/java/model/BaseballAnswerJudge.java
@@ -0,0 +1,13 @@
+package model;
+
+public class BaseballAnswerJudge implements AnswerJudge {
+
+    @Override
+    public Integer countStrikes(String input, String answer) {
+        int result = 0;
+        for (int index = 0; index < 3; index++) {
+            if (input.charAt(index) == answer.charAt(index)) result++;
+        }
+        return result;
+    }
+}
diff --git a/src/test/java/BaseballAnswerJudgeTest.java b/src/test/java/BaseballAnswerJudgeTest.java
new file mode 100644
index 00000000..147e0701
--- /dev/null
+++ b/src/test/java/BaseballAnswerJudgeTest.java
@@ -0,0 +1,38 @@
+import model.AnswerJudge;
+import model.BaseballAnswerJudge;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BaseballAnswerJudgeTest {
+
+    private AnswerJudge answerJudge;
+
+    @BeforeEach
+    void setup() {
+        answerJudge = new BaseballAnswerJudge();
+    }
+
+    @DisplayName("같은 위치의 숫자는 스트라이크로 판정한다")
+    @Test
+    void countStrikes_returnsCorrectCount_when_positionsMatch() {
+        int strikes = answerJudge.countStrikes("123", "153");
+        assertThat(strikes).isEqualTo(2);
+    }
+
+    @DisplayName("같은 위치의 숫자가 없으면 스트라이크는 0이다")
+    @Test
+    void countStrikes_returnsZero_when_noPositionMatches() {
+        int strikes = answerJudge.countStrikes("456", "123");
+        assertThat(strikes).isZero();
+    }
+
+    @DisplayName("모든 숫자와 위치가 같으면 스트라이크는 3이다")
+    @Test
+    void countStrikes_returnsThree_when_guessEqualsAnswer() {
+        int strikes = answerJudge.countStrikes("123", "123");
+        assertThat(strikes).isEqualTo(3);
+    }
+}

From 64e1ac44edfe6c4bd98429b9c2d43524047faf53 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 18:12:01 +0900
Subject: [PATCH 06/14] =?UTF-8?q?refactor:=20=EC=9D=B8=ED=84=B0=ED=8E=98?=
 =?UTF-8?q?=EC=9D=B4=EC=8A=A4=20=EC=A0=91=EA=B7=BC=EC=9E=90=20=EC=83=9D?=
 =?UTF-8?q?=EB=9E=B5?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/model/AnswerGenerator.java | 2 +-
 src/main/java/model/AnswerJudge.java     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/model/AnswerGenerator.java b/src/main/java/model/AnswerGenerator.java
index 23f1d3c7..f48f03b0 100644
--- a/src/main/java/model/AnswerGenerator.java
+++ b/src/main/java/model/AnswerGenerator.java
@@ -2,6 +2,6 @@
 
 public interface AnswerGenerator {
 
-    public String generateAnswer();
+    String generateAnswer();
 
 }
diff --git a/src/main/java/model/AnswerJudge.java b/src/main/java/model/AnswerJudge.java
index c6919dee..ba66d45d 100644
--- a/src/main/java/model/AnswerJudge.java
+++ b/src/main/java/model/AnswerJudge.java
@@ -2,6 +2,6 @@
 
 public interface AnswerJudge {
 
-    public Integer countStrikes(String input, String answer);
+    Integer countStrikes(String input, String answer);
 
 }

From 729baaacd36e4931165c96c3f6914921356f8d37 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 18:34:40 +0900
Subject: [PATCH 07/14] =?UTF-8?q?feat:=20=EB=B3=BC=20=ED=8C=90=EC=A0=95=20?=
 =?UTF-8?q?=EB=A1=9C=EC=A7=81=EC=9D=84=20=EC=B6=94=EA=B0=80=ED=95=A9?=
 =?UTF-8?q?=EB=8B=88=EB=8B=A4?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                                    |  2 +-
 src/main/java/model/AnswerJudge.java         |  1 +
 src/main/java/model/BaseballAnswerJudge.java | 10 ++++++++++
 src/test/java/BaseballAnswerJudgeTest.java   | 21 ++++++++++++++++++++
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index ce6af43e..84f67a81 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@
     - 제약 사항: 1부터 9까지만, 정답 길이 3
 - [ ] baseball 정답 판독
   - [X] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 반환합니다.
-  - [ ] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
+  - [X] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
   - [ ] strike or ball의 카운트가 0이 아닌 경우 출력하고, 모두 0인 경우 `낫싱`을 출력합니다.
 - [ ] baseball 게임 판단
   - [ ] 정답 판독기에서 판독한 값이 3스트라이크일 경우 출력하고 `3개의 숫자를 모두 맞히셨습니다! 게임 끝` 멘트와 게임을 종료합니다.
diff --git a/src/main/java/model/AnswerJudge.java b/src/main/java/model/AnswerJudge.java
index ba66d45d..1cb4941d 100644
--- a/src/main/java/model/AnswerJudge.java
+++ b/src/main/java/model/AnswerJudge.java
@@ -4,4 +4,5 @@ public interface AnswerJudge {
 
     Integer countStrikes(String input, String answer);
 
+    Integer countBalls(String input, String answer);
 }
diff --git a/src/main/java/model/BaseballAnswerJudge.java b/src/main/java/model/BaseballAnswerJudge.java
index 580ca608..d0615bb1 100644
--- a/src/main/java/model/BaseballAnswerJudge.java
+++ b/src/main/java/model/BaseballAnswerJudge.java
@@ -10,4 +10,14 @@ public Integer countStrikes(String input, String answer) {
         }
         return result;
     }
+
+    @Override
+    public Integer countBalls(String input, String answer) {
+        int result = 0;
+        for (int index = 0; index < 3; index++) {
+            char item = input.charAt(index);
+            if (item != answer.charAt(index) && answer.indexOf(item) != -1) result++;
+        }
+        return result;
+    }
 }
diff --git a/src/test/java/BaseballAnswerJudgeTest.java b/src/test/java/BaseballAnswerJudgeTest.java
index 147e0701..d5862401 100644
--- a/src/test/java/BaseballAnswerJudgeTest.java
+++ b/src/test/java/BaseballAnswerJudgeTest.java
@@ -35,4 +35,25 @@ void countStrikes_returnsThree_when_guessEqualsAnswer() {
         int strikes = answerJudge.countStrikes("123", "123");
         assertThat(strikes).isEqualTo(3);
     }
+
+    @DisplayName("같은 위치의 숫자는 볼로 판정하지 않는다.")
+    @Test
+    void countBalls_returnsCorrectCount_when_positionsMatch() {
+        int balls = answerJudge.countBalls("123", "153");
+        assertThat(balls).isEqualTo(0);
+    }
+
+    @DisplayName("같은 숫자가 위치가 다르면 볼이다.")
+    @Test
+    void countBalls_returnsOne_when_noPositionMatches_OneValueMatches() {
+        int balls = answerJudge.countBalls("456", "124");
+        assertThat(balls).isEqualTo(1);
+    }
+
+    @DisplayName("같은 숫자가 없으면 볼은 0이다.")
+    @Test
+    void countBalls_returnsZero_when_noPositionMatches() {
+        int balls = answerJudge.countBalls("123", "456");
+        assertThat(balls).isZero();
+    }
 }

From 553c6bf297e37038e359a14e0d78c1324a6c4f17 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 18:39:27 +0900
Subject: [PATCH 08/14] =?UTF-8?q?refactor:=20=EA=B8=B0=EB=8A=A5=20?=
 =?UTF-8?q?=EC=83=81=EC=84=B8=20=EA=B5=AC=ED=98=84=20=ED=8E=B8=EC=A7=91=20?=
 =?UTF-8?q?=EB=82=AB=EC=8B=B1=EC=9D=84=20=EB=B0=98=ED=99=98=ED=95=98?=
 =?UTF-8?q?=EB=8A=94=EA=B1=B4=20=EC=A0=95=EB=8B=B5=20=ED=8C=90=EB=8F=85?=
 =?UTF-8?q?=EA=B8=B0=EC=97=90=20=EB=93=A4=EC=96=B4=EA=B0=80=EB=8A=94?=
 =?UTF-8?q?=EA=B2=8C=20=EC=95=84=EB=8B=8C,=20=EC=9E=85=EC=B6=9C=EB=A0=A5?=
 =?UTF-8?q?=EC=97=90=EC=84=9C=20=ED=8C=90=EB=8B=A8=ED=95=98=EB=8A=94=20?=
 =?UTF-8?q?=EA=B2=83=EC=9D=B4=EB=9D=BC=EA=B3=A0=20=EC=83=9D=EA=B0=81?=
 =?UTF-8?q?=ED=95=B4=20=ED=8E=B8=EC=A7=91=ED=95=98=EC=98=80=EC=8A=B5?=
 =?UTF-8?q?=EB=8B=88=EB=8B=A4.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/README.md b/README.md
index 84f67a81..2aaf5ed7 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,6 @@
 - [ ] baseball 정답 판독
   - [X] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 반환합니다.
   - [X] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
-  - [ ] strike or ball의 카운트가 0이 아닌 경우 출력하고, 모두 0인 경우 `낫싱`을 출력합니다.
 - [ ] baseball 게임 판단
   - [ ] 정답 판독기에서 판독한 값이 3스트라이크일 경우 출력하고 `3개의 숫자를 모두 맞히셨습니다! 게임 끝` 멘트와 게임을 종료합니다.
   - [ ] 게임이 시작된 상황이라면 숫자를 입력 받고 판독 결과를 반환합니다.

From aa0339cccdb0fd2bf5befc30547d9503853020ef Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 20:25:57 +0900
Subject: [PATCH 09/14] =?UTF-8?q?feat:=20=EA=B2=8C=EC=9E=84=20=EC=A7=84?=
 =?UTF-8?q?=ED=96=89=20=EB=A1=9C=EC=A7=81=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                                    |  7 +-
 src/main/java/model/BaseballGameManager.java | 46 ++++++++++++
 src/main/java/model/GameManager.java         | 13 ++++
 src/test/java/BaseballGameManagerTest.java   | 76 ++++++++++++++++++++
 4 files changed, 138 insertions(+), 4 deletions(-)
 create mode 100644 src/main/java/model/BaseballGameManager.java
 create mode 100644 src/main/java/model/GameManager.java
 create mode 100644 src/test/java/BaseballGameManagerTest.java

diff --git a/README.md b/README.md
index 2aaf5ed7..92fc8481 100644
--- a/README.md
+++ b/README.md
@@ -23,12 +23,11 @@
 - [X] baseball 정답 생성
   - [X] 1부터 9까지의 다른 수로 이루어진 3자리의 수를 생성합니다.
     - 제약 사항: 1부터 9까지만, 정답 길이 3
-- [ ] baseball 정답 판독
+- [X] baseball 정답 판독
   - [X] 정답과 비교해서 자리와 숫자가 모두 같은 경우 strike의 카운트를 반환합니다.
   - [X] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
-- [ ] baseball 게임 판단
-  - [ ] 정답 판독기에서 판독한 값이 3스트라이크일 경우 출력하고 `3개의 숫자를 모두 맞히셨습니다! 게임 끝` 멘트와 게임을 종료합니다.
-  - [ ] 게임이 시작된 상황이라면 숫자를 입력 받고 판독 결과를 반환합니다.
+- [X] baseball 게임 진행
+  - [X] 게임이 시작된 상황이라면 숫자를 입력 받고 판독 결과를 반환합니다.
   - [ ] 게임이 진행중이 아니라면 1의 입력의 경우 정답 생성을 요청하고, 숫자 입력을 요구합니다.
   - [ ] 게임이 진행중이 아니라면 2의 입력의 경우 게임을 종료합니다.
 - [ ] 입력기
diff --git a/src/main/java/model/BaseballGameManager.java b/src/main/java/model/BaseballGameManager.java
new file mode 100644
index 00000000..ffe4b8e8
--- /dev/null
+++ b/src/main/java/model/BaseballGameManager.java
@@ -0,0 +1,46 @@
+package model;
+
+public class BaseballGameManager implements GameManager {
+    private final AnswerGenerator answerGenerator;
+    private final AnswerJudge answerJudge;
+    private String answer;
+    private boolean playing;
+    private boolean gameWon;
+
+    public BaseballGameManager(AnswerGenerator answerGenerator, AnswerJudge answerJudge) {
+        this.answerGenerator = answerGenerator;
+        this.answerJudge = answerJudge;
+        this.playing = false;
+        this.gameWon = false;
+    }
+
+    @Override
+    public void startGame() {
+        this.answer = answerGenerator.generateAnswer();
+        this.playing = true;
+        this.gameWon = false;
+    }
+
+    @Override
+    public int[] guess(String input) {
+        int strikes = answerJudge.countStrikes(input, answer);
+        int balls = answerJudge.countBalls(input, answer);
+
+        if (strikes == 3) {
+            this.playing = false;
+            this.gameWon = true;
+        }
+
+        return new int[]{strikes, balls};
+    }
+
+    @Override
+    public boolean isPlaying() {
+        return playing;
+    }
+
+    @Override
+    public boolean isGameWon() {
+        return gameWon;
+    }
+}
diff --git a/src/main/java/model/GameManager.java b/src/main/java/model/GameManager.java
new file mode 100644
index 00000000..054db87f
--- /dev/null
+++ b/src/main/java/model/GameManager.java
@@ -0,0 +1,13 @@
+package model;
+
+public interface GameManager {
+
+    void startGame();
+
+    int[] guess(String input);
+
+    boolean isPlaying();
+
+    boolean isGameWon();
+
+}
diff --git a/src/test/java/BaseballGameManagerTest.java b/src/test/java/BaseballGameManagerTest.java
new file mode 100644
index 00000000..34c08dc4
--- /dev/null
+++ b/src/test/java/BaseballGameManagerTest.java
@@ -0,0 +1,76 @@
+import model.AnswerGenerator;
+import model.AnswerJudge;
+import model.BaseballAnswerJudge;
+import model.BaseballGameManager;
+import model.GameManager;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BaseballGameManagerTest {
+
+    private GameManager gameManager;
+    private AnswerJudge answerJudge;
+
+    @BeforeEach
+    void setup() {
+        AnswerGenerator fixedAnswerGenerator = () -> "123";
+        answerJudge = new BaseballAnswerJudge();
+        gameManager = new BaseballGameManager(fixedAnswerGenerator, answerJudge);
+    }
+
+    @DisplayName("게임 시작 전에는 플레이 상태가 아니다")
+    @Test
+    void isPlaying_returnsFalse_beforeGameStart() {
+        assertThat(gameManager.isPlaying()).isFalse();
+    }
+
+    @DisplayName("게임 시작 후에는 플레이 상태이다")
+    @Test
+    void isPlaying_returnsTrue_afterGameStart() {
+        gameManager.startGame();
+        assertThat(gameManager.isPlaying()).isTrue();
+    }
+
+    @DisplayName("추측 시 스트라이크와 볼 개수를 반환한다")
+    @Test
+    void guess_returnsStrikesAndBalls() {
+        gameManager.startGame();
+        int[] result = gameManager.guess("145");
+        assertThat(result[0]).isEqualTo(1);
+        assertThat(result[1]).isEqualTo(0);
+    }
+
+    @DisplayName("3스트라이크 시 게임이 종료된다")
+    @Test
+    void guess_endsGame_whenThreeStrikes() {
+        gameManager.startGame();
+        int[] result = gameManager.guess("123");
+        assertThat(result[0]).isEqualTo(3);
+        assertThat(gameManager.isPlaying()).isFalse();
+        assertThat(gameManager.isGameWon()).isTrue();
+    }
+
+    @DisplayName("3스트라이크가 아니면 게임이 계속된다")
+    @Test
+    void guess_continuesGame_whenNotThreeStrikes() {
+        gameManager.startGame();
+        gameManager.guess("456");
+        assertThat(gameManager.isPlaying()).isTrue();
+        assertThat(gameManager.isGameWon()).isFalse();
+    }
+
+    @DisplayName("게임 재시작 시 상태가 초기화된다")
+    @Test
+    void startGame_resetsState_afterGameWon() {
+        gameManager.startGame();
+        gameManager.guess("123");
+        assertThat(gameManager.isGameWon()).isTrue();
+
+        gameManager.startGame();
+        assertThat(gameManager.isPlaying()).isTrue();
+        assertThat(gameManager.isGameWon()).isFalse();
+    }
+}

From 42e050818761c287bc78b3da9a113113f528e779 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 20:31:19 +0900
Subject: [PATCH 10/14] =?UTF-8?q?feat:=20=EC=9E=85=EB=A0=A5=20=EA=B2=80?=
 =?UTF-8?q?=EC=A6=9D=EA=B8=B0=20=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/model/BaseballInputValidator.java    | 46 +++++++++++++++
 src/main/java/model/InputValidator.java       |  7 +++
 src/test/java/BaseballInputValidatorTest.java | 57 +++++++++++++++++++
 3 files changed, 110 insertions(+)
 create mode 100644 src/main/java/model/BaseballInputValidator.java
 create mode 100644 src/main/java/model/InputValidator.java
 create mode 100644 src/test/java/BaseballInputValidatorTest.java

diff --git a/src/main/java/model/BaseballInputValidator.java b/src/main/java/model/BaseballInputValidator.java
new file mode 100644
index 00000000..a48c0a75
--- /dev/null
+++ b/src/main/java/model/BaseballInputValidator.java
@@ -0,0 +1,46 @@
+package model;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class BaseballInputValidator implements InputValidator {
+
+    @Override
+    public void validate(String input) {
+        validateLength(input);
+        validateDigitsOnly(input);
+        validateRange(input);
+        validateNoDuplicates(input);
+    }
+
+    private void validateLength(String input) {
+        if (input.length() != 3) {
+            throw new IllegalArgumentException("[ERROR] 3자리 숫자를 입력해주세요.");
+        }
+    }
+
+    private void validateDigitsOnly(String input) {
+        for (char c : input.toCharArray()) {
+            if (!Character.isDigit(c)) {
+                throw new IllegalArgumentException("[ERROR] 숫자만 입력해주세요.");
+            }
+        }
+    }
+
+    private void validateRange(String input) {
+        for (char c : input.toCharArray()) {
+            if (c == '0') {
+                throw new IllegalArgumentException("[ERROR] 1부터 9까지의 숫자만 입력해주세요.");
+            }
+        }
+    }
+
+    private void validateNoDuplicates(String input) {
+        Set<Character> seen = new HashSet<>();
+        for (char c : input.toCharArray()) {
+            if (!seen.add(c)) {
+                throw new IllegalArgumentException("[ERROR] 중복되지 않는 숫자를 입력해주세요.");
+            }
+        }
+    }
+}
diff --git a/src/main/java/model/InputValidator.java b/src/main/java/model/InputValidator.java
new file mode 100644
index 00000000..8715129d
--- /dev/null
+++ b/src/main/java/model/InputValidator.java
@@ -0,0 +1,7 @@
+package model;
+
+public interface InputValidator {
+
+    void validate(String input);
+
+}
diff --git a/src/test/java/BaseballInputValidatorTest.java b/src/test/java/BaseballInputValidatorTest.java
new file mode 100644
index 00000000..fb494d73
--- /dev/null
+++ b/src/test/java/BaseballInputValidatorTest.java
@@ -0,0 +1,57 @@
+import model.BaseballInputValidator;
+import model.InputValidator;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.Assertions.assertThatCode;
+
+public class BaseballInputValidatorTest {
+
+    private InputValidator validator;
+
+    @BeforeEach
+    void setup() {
+        validator = new BaseballInputValidator();
+    }
+
+    @DisplayName("올바른 입력은 예외가 발생하지 않는다")
+    @Test
+    void validate_doesNotThrow_whenValidInput() {
+        assertThatCode(() -> validator.validate("123"))
+                .doesNotThrowAnyException();
+    }
+
+    @DisplayName("3자리가 아니면 예외가 발생한다")
+    @Test
+    void validate_throwsException_whenLengthIsNotThree() {
+        assertThatThrownBy(() -> validator.validate("12"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("[ERROR]");
+    }
+
+    @DisplayName("숫자가 아닌 문자가 포함되면 예외가 발생한다")
+    @Test
+    void validate_throwsException_whenContainsNonDigit() {
+        assertThatThrownBy(() -> validator.validate("12a"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("[ERROR]");
+    }
+
+    @DisplayName("0이 포함되면 예외가 발생한다")
+    @Test
+    void validate_throwsException_whenContainsZero() {
+        assertThatThrownBy(() -> validator.validate("012"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("[ERROR]");
+    }
+
+    @DisplayName("중복된 숫자가 있으면 예외가 발생한다")
+    @Test
+    void validate_throwsException_whenHasDuplicates() {
+        assertThatThrownBy(() -> validator.validate("112"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("[ERROR]");
+    }
+}

From 14f27c4cd351176ae191f1f2893cea1110c66681 Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 21:10:17 +0900
Subject: [PATCH 11/14] =?UTF-8?q?feat:=20controller=EC=99=80=20view,=20?=
 =?UTF-8?q?=EC=9E=85=EB=A0=A5=EA=B8=B0=20=EC=B6=9C=EB=A0=A5=EA=B8=B0=20?=
 =?UTF-8?q?=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/controller/GameController.java | 56 ++++++++++++++++++++
 src/main/java/view/OutputView.java           | 40 ++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 src/main/java/controller/GameController.java
 create mode 100644 src/main/java/view/OutputView.java

diff --git a/src/main/java/controller/GameController.java b/src/main/java/controller/GameController.java
new file mode 100644
index 00000000..975aa978
--- /dev/null
+++ b/src/main/java/controller/GameController.java
@@ -0,0 +1,56 @@
+package controller;
+
+import model.GameManager;
+import model.InputValidator;
+import view.OutputView;
+
+import java.util.Scanner;
+
+public class GameController {
+
+    private final GameManager gameManager;
+    private final InputValidator inputValidator;
+    private final OutputView outputView;
+    private final Scanner scanner;
+
+    public GameController(GameManager gameManager, InputValidator inputValidator, OutputView outputView) {
+        this.gameManager = gameManager;
+        this.inputValidator = inputValidator;
+        this.outputView = outputView;
+        this.scanner = new Scanner(System.in);
+    }
+
+    public void run() {
+        outputView.printGameStart();
+        while (true) {
+            playGame();
+            if (!askRestart()) break;
+        }
+    }
+
+    private void playGame() {
+        gameManager.startGame();
+        while (gameManager.isPlaying()) {
+            outputView.printInputPrompt();
+            String input = scanner.nextLine();
+            processGuess(input);
+        }
+        outputView.printGameWon();
+    }
+
+    private void processGuess(String input) {
+        try {
+            inputValidator.validate(input);
+            int[] result = gameManager.guess(input);
+            outputView.printResult(result[0], result[1]);
+        } catch (IllegalArgumentException e) {
+            outputView.printError(e.getMessage());
+        }
+    }
+
+    private boolean askRestart() {
+        outputView.printRestartPrompt();
+        String input = scanner.nextLine();
+        return input.equals("1");
+    }
+}
diff --git a/src/main/java/view/OutputView.java b/src/main/java/view/OutputView.java
new file mode 100644
index 00000000..00db7933
--- /dev/null
+++ b/src/main/java/view/OutputView.java
@@ -0,0 +1,40 @@
+package view;
+
+public class OutputView {
+
+    public void printGameStart() {
+        System.out.println("숫자 야구 게임을 시작합니다.");
+    }
+
+    public void printInputPrompt() {
+        System.out.print("숫자를 입력해주세요 : ");
+    }
+
+    public void printResult(int strikes, int balls) {
+        if (strikes == 0 && balls == 0) {
+            System.out.println("낫싱");
+            return;
+        }
+
+        StringBuilder result = new StringBuilder();
+        if (balls > 0) {
+            result.append(balls).append("볼 ");
+        }
+        if (strikes > 0) {
+            result.append(strikes).append("스트라이크");
+        }
+        System.out.println(result.toString().trim());
+    }
+
+    public void printGameWon() {
+        System.out.println("3개의 숫자를 모두 맞히셨습니다! 게임 종료");
+    }
+
+    public void printRestartPrompt() {
+        System.out.println("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.");
+    }
+
+    public void printError(String message) {
+        System.out.println(message);
+    }
+}

From 8872bdc90f45a7479fe3ee063c2ba6c8cd798c8c Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 21:18:16 +0900
Subject: [PATCH 12/14] =?UTF-8?q?docs:=20=EA=B5=AC=ED=98=84=20=EC=99=84?=
 =?UTF-8?q?=EB=A3=8C=20=EC=B2=B4=ED=81=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 92fc8481..e2da9c64 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@
   - [X] 정답과 비교해서 숫자만 같고 자리만 같을 경우 ball 의 카운트를 올립니다.
 - [X] baseball 게임 진행
   - [X] 게임이 시작된 상황이라면 숫자를 입력 받고 판독 결과를 반환합니다.
-  - [ ] 게임이 진행중이 아니라면 1의 입력의 경우 정답 생성을 요청하고, 숫자 입력을 요구합니다.
-  - [ ] 게임이 진행중이 아니라면 2의 입력의 경우 게임을 종료합니다.
-- [ ] 입력기
-- [ ] 출력기
+  - [X] 게임이 진행중이 아니라면 1의 입력의 경우 정답 생성을 요청하고, 숫자 입력을 요구합니다.
+  - [X] 게임이 진행중이 아니라면 2의 입력의 경우 게임을 종료합니다.
+- [X] 입력기
+- [X] 출력기

From b5884b7c7ee22d776ee18edf04393e0698b4e50c Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Wed, 28 Jan 2026 21:25:57 +0900
Subject: [PATCH 13/14] =?UTF-8?q?feat:=20main=20=ED=95=A8=EC=88=98?=
 =?UTF-8?q?=EC=99=80=20=EC=84=A4=EC=A0=95=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/Main.java              | 10 ++++++++++
 src/main/java/config/GameConfig.java | 27 +++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 src/main/java/Main.java
 create mode 100644 src/main/java/config/GameConfig.java

diff --git a/src/main/java/Main.java b/src/main/java/Main.java
new file mode 100644
index 00000000..35200557
--- /dev/null
+++ b/src/main/java/Main.java
@@ -0,0 +1,10 @@
+import config.GameConfig;
+import controller.GameController;
+
+public class Main {
+
+    public static void main(String[] args) {
+        GameController gameController = new GameConfig().gameController();
+        gameController.run();
+    }
+}
diff --git a/src/main/java/config/GameConfig.java b/src/main/java/config/GameConfig.java
new file mode 100644
index 00000000..16a2feb8
--- /dev/null
+++ b/src/main/java/config/GameConfig.java
@@ -0,0 +1,27 @@
+package config;
+
+import controller.GameController;
+import model.BaseballAnswerGenerator;
+import model.BaseballAnswerJudge;
+import model.BaseballGameManager;
+import model.BaseballInputValidator;
+import view.OutputView;
+
+public class GameConfig {
+
+    public GameController gameController() {
+        return new GameController(
+                gameManager(),
+                new BaseballInputValidator(),
+                new OutputView()
+        );
+    }
+
+    private BaseballGameManager gameManager() {
+        return new BaseballGameManager(
+                new BaseballAnswerGenerator(),
+                new BaseballAnswerJudge()
+        );
+    }
+
+}

From a2c984c91af63803d2ad25f6c07c73ab49ba1e4d Mon Sep 17 00:00:00 2001
From: cheesecrust <jack0810@naver.com>
Date: Tue, 3 Feb 2026 20:41:55 +0900
Subject: [PATCH 14/14] =?UTF-8?q?refactor:=20=EC=83=81=EC=88=98=20?=
 =?UTF-8?q?=ED=8C=8C=EC=9D=BC=EB=A1=9C=20=EB=B9=BC=EA=B8=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/constant/GameConstants.java        |  9 +++++++++
 src/main/java/constant/GameMessages.java         | 16 ++++++++++++++++
 src/main/java/controller/GameController.java     |  3 ++-
 src/main/java/model/BaseballAnswerGenerator.java | 11 ++++++++---
 src/main/java/model/BaseballAnswerJudge.java     | 14 ++++++++++----
 src/main/java/model/BaseballGameManager.java     |  4 +++-
 src/main/java/model/BaseballInputValidator.java  | 15 +++++++++------
 src/main/java/view/OutputView.java               | 16 +++++++++-------
 8 files changed, 66 insertions(+), 22 deletions(-)
 create mode 100644 src/main/java/constant/GameConstants.java
 create mode 100644 src/main/java/constant/GameMessages.java

diff --git a/src/main/java/constant/GameConstants.java b/src/main/java/constant/GameConstants.java
new file mode 100644
index 00000000..ec10db91
--- /dev/null
+++ b/src/main/java/constant/GameConstants.java
@@ -0,0 +1,9 @@
+package constant;
+
+public class GameConstants {
+    public static final int ANSWER_LENGTH = 3;
+    public static final int MIN_DIGIT = 1;
+    public static final int MAX_DIGIT = 9;
+    public static final char EXCLUDED_DIGIT = '0';
+    public static final String RESTART_COMMAND = "1";
+}
diff --git a/src/main/java/constant/GameMessages.java b/src/main/java/constant/GameMessages.java
new file mode 100644
index 00000000..078df844
--- /dev/null
+++ b/src/main/java/constant/GameMessages.java
@@ -0,0 +1,16 @@
+package constant;
+
+public class GameMessages {
+    public static final String GAME_START = "숫자 야구 게임을 시작합니다.";
+    public static final String INPUT_PROMPT = "숫자를 입력해주세요 : ";
+    public static final String NOTHING = "낫싱";
+    public static final String BALL = "볼";
+    public static final String STRIKE = "스트라이크";
+    public static final String GAME_WON = "3개의 숫자를 모두 맞히셨습니다! 게임 종료";
+    public static final String RESTART_PROMPT = "게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.";
+
+    public static final String ERROR_INVALID_LENGTH = "[ERROR] 3자리 숫자를 입력해주세요.";
+    public static final String ERROR_NOT_DIGIT = "[ERROR] 숫자만 입력해주세요.";
+    public static final String ERROR_INVALID_RANGE = "[ERROR] 1부터 9까지의 숫자만 입력해주세요.";
+    public static final String ERROR_DUPLICATE = "[ERROR] 중복되지 않는 숫자를 입력해주세요.";
+}
diff --git a/src/main/java/controller/GameController.java b/src/main/java/controller/GameController.java
index 975aa978..858ac58c 100644
--- a/src/main/java/controller/GameController.java
+++ b/src/main/java/controller/GameController.java
@@ -1,5 +1,6 @@
 package controller;
 
+import constant.GameConstants;
 import model.GameManager;
 import model.InputValidator;
 import view.OutputView;
@@ -51,6 +52,6 @@ private void processGuess(String input) {
     private boolean askRestart() {
         outputView.printRestartPrompt();
         String input = scanner.nextLine();
-        return input.equals("1");
+        return input.equals(GameConstants.RESTART_COMMAND);
     }
 }
diff --git a/src/main/java/model/BaseballAnswerGenerator.java b/src/main/java/model/BaseballAnswerGenerator.java
index ae5ae9c0..b56bce45 100644
--- a/src/main/java/model/BaseballAnswerGenerator.java
+++ b/src/main/java/model/BaseballAnswerGenerator.java
@@ -1,17 +1,22 @@
 package model;
 
+import constant.GameConstants;
+
 import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.ThreadLocalRandom;
 
-public class BaseballAnswerGenerator implements AnswerGenerator{
+public class BaseballAnswerGenerator implements AnswerGenerator {
 
     @Override
     public String generateAnswer() {
         Set<Integer> numbers = new HashSet<>();
 
-        while (numbers.size() < 3) {
-            numbers.add(ThreadLocalRandom.current().nextInt(1, 10));
+        while (numbers.size() < GameConstants.ANSWER_LENGTH) {
+            numbers.add(ThreadLocalRandom.current().nextInt(
+                    GameConstants.MIN_DIGIT,
+                    GameConstants.MAX_DIGIT + 1
+            ));
         }
 
         StringBuilder answer = new StringBuilder();
diff --git a/src/main/java/model/BaseballAnswerJudge.java b/src/main/java/model/BaseballAnswerJudge.java
index d0615bb1..b280c985 100644
--- a/src/main/java/model/BaseballAnswerJudge.java
+++ b/src/main/java/model/BaseballAnswerJudge.java
@@ -1,12 +1,16 @@
 package model;
 
+import constant.GameConstants;
+
 public class BaseballAnswerJudge implements AnswerJudge {
 
     @Override
     public Integer countStrikes(String input, String answer) {
         int result = 0;
-        for (int index = 0; index < 3; index++) {
-            if (input.charAt(index) == answer.charAt(index)) result++;
+        for (int index = 0; index < GameConstants.ANSWER_LENGTH; index++) {
+            if (input.charAt(index) == answer.charAt(index)) {
+                result++;
+            }
         }
         return result;
     }
@@ -14,9 +18,11 @@ public Integer countStrikes(String input, String answer) {
     @Override
     public Integer countBalls(String input, String answer) {
         int result = 0;
-        for (int index = 0; index < 3; index++) {
+        for (int index = 0; index < GameConstants.ANSWER_LENGTH; index++) {
             char item = input.charAt(index);
-            if (item != answer.charAt(index) && answer.indexOf(item) != -1) result++;
+            if (item != answer.charAt(index) && answer.indexOf(item) != -1) {
+                result++;
+            }
         }
         return result;
     }
diff --git a/src/main/java/model/BaseballGameManager.java b/src/main/java/model/BaseballGameManager.java
index ffe4b8e8..06ac6a25 100644
--- a/src/main/java/model/BaseballGameManager.java
+++ b/src/main/java/model/BaseballGameManager.java
@@ -1,5 +1,7 @@
 package model;
 
+import constant.GameConstants;
+
 public class BaseballGameManager implements GameManager {
     private final AnswerGenerator answerGenerator;
     private final AnswerJudge answerJudge;
@@ -26,7 +28,7 @@ public int[] guess(String input) {
         int strikes = answerJudge.countStrikes(input, answer);
         int balls = answerJudge.countBalls(input, answer);
 
-        if (strikes == 3) {
+        if (strikes == GameConstants.ANSWER_LENGTH) {
             this.playing = false;
             this.gameWon = true;
         }
diff --git a/src/main/java/model/BaseballInputValidator.java b/src/main/java/model/BaseballInputValidator.java
index a48c0a75..4b1d3a1c 100644
--- a/src/main/java/model/BaseballInputValidator.java
+++ b/src/main/java/model/BaseballInputValidator.java
@@ -1,5 +1,8 @@
 package model;
 
+import constant.GameConstants;
+import constant.GameMessages;
+
 import java.util.HashSet;
 import java.util.Set;
 
@@ -14,23 +17,23 @@ public void validate(String input) {
     }
 
     private void validateLength(String input) {
-        if (input.length() != 3) {
-            throw new IllegalArgumentException("[ERROR] 3자리 숫자를 입력해주세요.");
+        if (input.length() != GameConstants.ANSWER_LENGTH) {
+            throw new IllegalArgumentException(GameMessages.ERROR_INVALID_LENGTH);
         }
     }
 
     private void validateDigitsOnly(String input) {
         for (char c : input.toCharArray()) {
             if (!Character.isDigit(c)) {
-                throw new IllegalArgumentException("[ERROR] 숫자만 입력해주세요.");
+                throw new IllegalArgumentException(GameMessages.ERROR_NOT_DIGIT);
             }
         }
     }
 
     private void validateRange(String input) {
         for (char c : input.toCharArray()) {
-            if (c == '0') {
-                throw new IllegalArgumentException("[ERROR] 1부터 9까지의 숫자만 입력해주세요.");
+            if (c == GameConstants.EXCLUDED_DIGIT) {
+                throw new IllegalArgumentException(GameMessages.ERROR_INVALID_RANGE);
             }
         }
     }
@@ -39,7 +42,7 @@ private void validateNoDuplicates(String input) {
         Set<Character> seen = new HashSet<>();
         for (char c : input.toCharArray()) {
             if (!seen.add(c)) {
-                throw new IllegalArgumentException("[ERROR] 중복되지 않는 숫자를 입력해주세요.");
+                throw new IllegalArgumentException(GameMessages.ERROR_DUPLICATE);
             }
         }
     }
diff --git a/src/main/java/view/OutputView.java b/src/main/java/view/OutputView.java
index 00db7933..4d48c225 100644
--- a/src/main/java/view/OutputView.java
+++ b/src/main/java/view/OutputView.java
@@ -1,37 +1,39 @@
 package view;
 
+import constant.GameMessages;
+
 public class OutputView {
 
     public void printGameStart() {
-        System.out.println("숫자 야구 게임을 시작합니다.");
+        System.out.println(GameMessages.GAME_START);
     }
 
     public void printInputPrompt() {
-        System.out.print("숫자를 입력해주세요 : ");
+        System.out.print(GameMessages.INPUT_PROMPT);
     }
 
     public void printResult(int strikes, int balls) {
         if (strikes == 0 && balls == 0) {
-            System.out.println("낫싱");
+            System.out.println(GameMessages.NOTHING);
             return;
         }
 
         StringBuilder result = new StringBuilder();
         if (balls > 0) {
-            result.append(balls).append("볼 ");
+            result.append(balls).append(GameMessages.BALL).append(" ");
         }
         if (strikes > 0) {
-            result.append(strikes).append("스트라이크");
+            result.append(strikes).append(GameMessages.STRIKE);
         }
         System.out.println(result.toString().trim());
     }
 
     public void printGameWon() {
-        System.out.println("3개의 숫자를 모두 맞히셨습니다! 게임 종료");
+        System.out.println(GameMessages.GAME_WON);
     }
 
     public void printRestartPrompt() {
-        System.out.println("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.");
+        System.out.println(GameMessages.RESTART_PROMPT);
     }
 
     public void printError(String message) {