diff --git a/README.md b/README.md
index 8d7e8aee..787b5968 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,25 @@
-# java-baseball-precourse
\ No newline at end of file
+## 구현할 기능 목록
+
+### 1. 게임 실행 기능
+- [x] 숫자 생성 기능
+- [x] 스트라이크, 볼 판별 로직
+- [x] 스트라이크, 볼 관련 결과값 저장
+
+### 2. 입력 및 출력 관련
+- [x] 숫자 입력 및 결과값 출력
+- [x] 숫자 입력 관련 유효성 검증 로직 도입
+
+### 3. 단위 테스트 계획
+- [x] `NumberGeneratorTest`
+  - [x] 3자리의 숫자인지 검증
+  - [x] 각 자리수가 중복되지 않는지 검증
+  - [x] 각 자리수가 1-9 사이의 숫자인지 검증
+- [x] `BaseballGameTest` (target: "123")
+  - [x] 3 스트라이크 (e.g., "123")
+  - [x] 3 볼 (e.g., "312")
+  - [x] 1 스트라이크 2 볼 (e.g., "132")
+  - [x] 낫싱 (e.g., "456")
+- [x] `ResultTest`
+  - [x] 3 스트라이크일 때 `isWin()`이 true인지 검증
+  - [x] 3 스트라이크가 아닐 때 `isWin()`이 false인지 검증
+  - [x] 0 스트라이크, 0 볼일 때 `isNothing()`이 true인지 검증
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diff --git a/src/main/java/baseball/Application.java b/src/main/java/baseball/Application.java
new file mode 100644
index 00000000..c3f3a97e
--- /dev/null
+++ b/src/main/java/baseball/Application.java
@@ -0,0 +1,135 @@
+package baseball;
+
+import java.util.Scanner;
+
+public class Application {
+    private static final int GAME_SIZE = 3;
+    private static final String ERROR_PREFIX = "[ERROR] ";
+    private static final String INPUT_PROMPT = "숫자를 입력해주세요 : ";
+    private static final String RESTART_PROMPT = "게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.";
+    private static final String GAME_OVER_MESSAGE = "3개의 숫자를 모두 맞히셨습니다! 게임 종료";
+
+    public static void main(String[] args) {
+        Application app = new Application();
+        app.run();
+    }
+
+    public void run() {
+        try (Scanner scanner = new Scanner(System.in)) {
+            play(scanner);
+        }
+    }
+
+    private void play(Scanner scanner) {
+        boolean restart = true;
+        while (restart) {
+            String targetNumber = new NumberGenerator().generate();
+            playOneGame(scanner, targetNumber);
+            restart = shouldRestart(scanner);
+        }
+    }
+
+    private void playOneGame(Scanner scanner, String targetNumber) {
+        BaseballGame game = new BaseballGame(targetNumber);
+        boolean isFinished = false;
+        while (!isFinished) {
+            String inputNumber = readUserNumber(scanner);
+            if (!isValidUserNumber(inputNumber)) {
+                continue;
+            }
+            Result result = game.play(inputNumber);
+            isFinished = processGameResult(result);
+        }
+    }
+
+    private boolean processGameResult(Result result) {
+        System.out.println(formatResult(result));
+        if (result.isWin()) {
+            System.out.println(GAME_OVER_MESSAGE);
+            return true;
+        }
+        return false;
+    }
+
+    private String readUserNumber(Scanner scanner) {
+        System.out.print(INPUT_PROMPT);
+        return scanner.nextLine();
+    }
+
+    private boolean isValidUserNumber(String inputNumber) {
+        if (inputNumber == null) {
+            System.out.println(ERROR_PREFIX + "입력값이 올바르지 않습니다.");
+            return false;
+        }
+        if (inputNumber.length() != GAME_SIZE) {
+            System.out.println(ERROR_PREFIX + "3자리 숫자를 입력해야 합니다.");
+            return false;
+        }
+        if (!areDigitsValid(inputNumber)) {
+            return false;
+        }
+        if (hasDuplicateDigits(inputNumber)) {
+            System.out.println(ERROR_PREFIX + "서로 다른 숫자를 입력해야 합니다.");
+            return false;
+        }
+        return true;
+    }
+
+    private boolean areDigitsValid(String inputNumber) {
+        for (int i = 0; i < GAME_SIZE; i++) {
+            char c = inputNumber.charAt(i);
+            if (c < '1' || c > '9') {
+                System.out.println(ERROR_PREFIX + "1부터 9까지 숫자만 입력해야 합니다.");
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean hasDuplicateDigits(String inputNumber) {
+        for (int i = 0; i < GAME_SIZE; i++) {
+            if (isCharDuplicatedInRestOfString(inputNumber, i)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean isCharDuplicatedInRestOfString(String inputNumber, int index) {
+        char currentChar = inputNumber.charAt(index);
+        for (int j = index + 1; j < GAME_SIZE; j++) {
+            if (currentChar == inputNumber.charAt(j)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean shouldRestart(Scanner scanner) {
+        while (true) {
+            System.out.println(RESTART_PROMPT);
+            String input = scanner.nextLine();
+            if ("1".equals(input)) {
+                return true;
+            }
+            if ("2".equals(input)) {
+                return false;
+            }
+            System.out.println(ERROR_PREFIX + "1 또는 2를 입력해야 합니다.");
+        }
+    }
+
+    private String formatResult(Result result) {
+        if (result.isNothing()) {
+            return "낫싱";
+        }
+        StringBuilder res = new StringBuilder();
+        if (result.getStrikeCount() > 0) {
+            res.append(result.getStrikeCount()).append(" 스트라이크 ");
+        }
+        if (result.getBallCount() > 0) {
+            res.append(result.getBallCount()).append(" 볼");
+        }
+        return res.toString().trim();
+    }
+}
diff --git a/src/main/java/baseball/BaseballGame.java b/src/main/java/baseball/BaseballGame.java
new file mode 100644
index 00000000..22809894
--- /dev/null
+++ b/src/main/java/baseball/BaseballGame.java
@@ -0,0 +1,55 @@
+package baseball;
+
+public class BaseballGame {
+    private static final int GAME_SIZE = 3;
+
+    private final String targetNumber;
+
+    public BaseballGame(String targetNumber) {
+        this.targetNumber = targetNumber;
+    }
+
+    public Result play(String inputNumber) {
+        int strikeCount = countStrikes(inputNumber);
+        int ballCount = countBalls(inputNumber);
+        return new Result(strikeCount, ballCount);
+    }
+
+    private int countStrikes(String inputNumber) {
+        int strikeCount = 0;
+        for (int i = 0; i < GAME_SIZE; i++) {
+            strikeCount += getStrikeIncrement(inputNumber.charAt(i), i);
+        }
+        return strikeCount;
+    }
+
+    private int getStrikeIncrement(char inputChar, int index) {
+        if (isStrike(inputChar, index)) {
+            return 1;
+        }
+        return 0;
+    }
+
+    private int countBalls(String inputNumber) {
+        int ballCount = 0;
+        for (int i = 0; i < GAME_SIZE; i++) {
+            ballCount += getBallIncrement(inputNumber.charAt(i), i);
+        }
+        return ballCount;
+    }
+
+    private int getBallIncrement(char inputChar, int index) {
+        if (isBall(inputChar, index)) {
+            return 1;
+        }
+        return 0;
+    }
+
+    private boolean isStrike(char inputChar, int index) {
+        return targetNumber.charAt(index) == inputChar;
+    }
+
+    private boolean isBall(char inputChar, int index) {
+        return !isStrike(inputChar, index) && targetNumber.contains(String.valueOf(inputChar));
+    }
+}
diff --git a/src/main/java/baseball/NumberGenerator.java b/src/main/java/baseball/NumberGenerator.java
new file mode 100644
index 00000000..3f4d6698
--- /dev/null
+++ b/src/main/java/baseball/NumberGenerator.java
@@ -0,0 +1,20 @@
+package baseball;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class NumberGenerator {
+    public String generate() {
+        List<Integer> numbers = new ArrayList<>();
+        for (int i = 1; i <= 9; i++) {
+            numbers.add(i);
+        }
+        Collections.shuffle(numbers);
+        StringBuilder result = new StringBuilder();
+        for (int i = 0; i < 3; i++) {
+            result.append(numbers.get(i));
+        }
+        return result.toString();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/baseball/Result.java b/src/main/java/baseball/Result.java
new file mode 100644
index 00000000..6938cb11
--- /dev/null
+++ b/src/main/java/baseball/Result.java
@@ -0,0 +1,28 @@
+package baseball;
+
+public class Result {
+    private final int strikeCount;
+    private final int ballCount;
+
+    public Result(int strikeCount, int ballCount) {
+        this.strikeCount = strikeCount;
+        this.ballCount = ballCount;
+    }
+
+    public int getStrikeCount() {
+        return strikeCount;
+    }
+
+    public int getBallCount() {
+        return ballCount;
+    }
+
+    public boolean isNothing() {
+        return strikeCount == 0 && ballCount == 0;
+    }
+
+    public boolean isWin() {
+        return strikeCount == 3;
+    }
+}
+
diff --git a/src/test/java/baseball/BaseballGameTest.java b/src/test/java/baseball/BaseballGameTest.java
new file mode 100644
index 00000000..0ffc687e
--- /dev/null
+++ b/src/test/java/baseball/BaseballGameTest.java
@@ -0,0 +1,40 @@
+package baseball;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class BaseballGameTest {
+
+    private final BaseballGame game = new BaseballGame("123");
+
+    @ParameterizedTest
+    @MethodSource("gameScenarios")
+    @DisplayName("스트라이크와 볼 개수를 정확히 계산한다")
+    void play_calculatesStrikesAndBallsCorrectly(String input, int expectedStrikes, int expectedBalls) {
+        Result result = game.play(input);
+
+        assertThat(result.getStrikeCount()).isEqualTo(expectedStrikes);
+        assertThat(result.getBallCount()).isEqualTo(expectedBalls);
+    }
+
+    static Stream<Arguments> gameScenarios() {
+        return Stream.of(
+                // 계획된 테스트 케이스
+                Arguments.of("123", 3, 0), // 3 스트라이크
+                Arguments.of("312", 0, 3), // 3 볼
+                Arguments.of("132", 1, 2), // 1 스트라이크 2 볼
+                Arguments.of("456", 0, 0), // 낫싱
+
+                // 견고성을 위한 추가 케이스
+                Arguments.of("124", 2, 0), // 2 스트라이크
+                Arguments.of("415", 0, 1), // 1 볼
+                Arguments.of("142", 1, 1)  // 1 스트라이크 1 볼
+        );
+    }
+}
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diff --git a/src/test/java/baseball/NumberGeneratorTest.java b/src/test/java/baseball/NumberGeneratorTest.java
new file mode 100644
index 00000000..57db9855
--- /dev/null
+++ b/src/test/java/baseball/NumberGeneratorTest.java
@@ -0,0 +1,41 @@
+package baseball;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.RepeatedTest;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class NumberGeneratorTest {
+
+    private final NumberGenerator generator = new NumberGenerator();
+
+    @RepeatedTest(10)
+    @DisplayName("생성된 숫자는 3자리이다")
+    void generates_a_3_digit_number() {
+        String number = generator.generate();
+        assertThat(number).hasSize(3);
+    }
+
+    @RepeatedTest(10)
+    @DisplayName("생성된 숫자는 1-9 사이의 값이다")
+    void generates_digits_between_1_and_9() {
+        String number = generator.generate();
+        for (char c : number.toCharArray()) {
+            assertThat(c).isGreaterThanOrEqualTo('1').isLessThanOrEqualTo('9');
+        }
+    }
+
+    @RepeatedTest(10)
+    @DisplayName("생성된 숫자는 서로 다른 수로 이루어져 있다")
+    void generates_a_number_with_unique_digits() {
+        String number = generator.generate();
+        Set<Character> uniqueDigits = new HashSet<>();
+        for (char c : number.toCharArray()) {
+            uniqueDigits.add(c);
+        }
+        assertThat(uniqueDigits).hasSize(3);
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/baseball/ResultTest.java b/src/test/java/baseball/ResultTest.java
new file mode 100644
index 00000000..9a8fd5d6
--- /dev/null
+++ b/src/test/java/baseball/ResultTest.java
@@ -0,0 +1,57 @@
+package baseball;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DisplayName("Result 클래스")
+class ResultTest {
+
+    @Nested
+    @DisplayName("isWin 메소드는")
+    class IsWinTest {
+
+        @Test
+        @DisplayName("3 스트라이크일 때 true를 반환한다")
+        void returns_true_for_3_strikes() {
+            Result result = new Result(3, 0);
+            assertThat(result.isWin()).isTrue();
+        }
+
+        @Test
+        @DisplayName("3 스트라이크가 아닐 때 false를 반환한다")
+        void returns_false_for_less_than_3_strikes() {
+            Result resultWith2Strikes = new Result(2, 1);
+            Result resultWith0Strikes = new Result(0, 2);
+
+            assertThat(resultWith2Strikes.isWin()).isFalse();
+            assertThat(resultWith0Strikes.isWin()).isFalse();
+        }
+    }
+
+    @Nested
+    @DisplayName("isNothing 메소드는")
+    class IsNothingTest {
+
+        @Test
+        @DisplayName("0 스트라이크, 0 볼일 때 true를 반환한다")
+        void returns_true_for_0_strikes_and_0_balls() {
+            Result result = new Result(0, 0);
+            assertThat(result.isNothing()).isTrue();
+        }
+
+        @Test
+        @DisplayName("스트라이크나 볼이 하나라도 있으면 false를 반환한다")
+        void returns_false_if_strikes_or_balls_exist() {
+            Result resultWithStrikes = new Result(1, 0);
+            Result resultWithBalls = new Result(0, 2);
+            Result resultWithBoth = new Result(1, 1);
+
+            assertThat(resultWithStrikes.isNothing()).isFalse();
+            assertThat(resultWithBalls.isNothing()).isFalse();
+            assertThat(resultWithBoth.isNothing()).isFalse();
+        }
+    }
+}