diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..2e82af5
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 woowacourse
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index d5b0084..e2c4cc8 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,21 @@
 # 미션 - 숫자 야구 게임
 
+## 구현할 기능
+- 게임 시작
+- 3개의 임의의 수 생성
+- 사용자 입력 요구문 출력
+- 사용자 입력
+  - 비정상적인 입력 처리
+    - 세자리 수가 아닐 경우
+    - 중복 수가 입력될 경우
+    - 0이 입력될 경우
+- 사용자 입력과 임의의 수 비교
+  - 스트라이크 판정
+  - 볼 판정
+  - 낫싱 판정
+  - 판정 결과 출력
+- 재시작 여부 확인
+
 ## 🚀 기능 요구사항
 - 이 게임은 프로그램이 1에서 9까지 서로 다른 임의의 수 3개를 정하고 이를 플레이어가 맞추는 게임이다.
 - 정답을 맞추기 위해 3자리수를 입력하고 힌트를 받는다.
@@ -56,7 +72,7 @@
 
 ## 🎱 프로그래밍 요구사항
 - 자바 코드 컨벤션을 지키면서 프로그래밍한다.
-  - 기본적으로 [Google Java Style Guide](https://google.github.io/styleguide/javaguide.html) 문서와 [네이버 핵데이 Java 컨벤션](https://naver.github.io/hackday-conventions-java/)을 원칙으로 한다.
+  - 기본적으로 [Google Java Style Guide](https://google.github.io/styleguide/javaguide.html)을 원칙으로 한다.
   - 단, 들여쓰기는 '2 spaces'가 아닌 '4 spaces'로 한다.
 - indent(인덴트, 들여쓰기) depth를 3이 넘지 않도록 구현한다. 2까지만 허용한다.
   - 예를 들어 while문 안에 if문이 있으면 들여쓰기는 2이다.
@@ -69,13 +85,13 @@
 ### 프로그래밍 요구사항 - Application
 - Application 클래스를 활용해 구현해야 한다.
 - Application의 패키지 구조와 구현은 변경하지 않는다.
-- `Scanner scanner = new Scanner(System.in);`는 변경하지 않는다.
+- `final Scanner scanner = new Scanner(System.in);`는 변경하지 않는다.
 - `// TODO 구현 진행` 이 후 부터 구현한다.
 
 ```java
 public class Application {
     public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
+        final Scanner scanner = new Scanner(System.in);
         // TODO 구현 진행
     }
 }
@@ -96,10 +112,11 @@ private static final Random RANDOM = new Random();
 <br>
 
 ## 📈 진행 요구사항
-- 미션은 현재 저장소를 fork & clone해서 시작한다.
+- 미션은 [java-baseball-precourse 저장소](https://github.com/woowacourse/java-baseball-precourse) 를 fork/clone해 시작한다.
 - 기능을 구현하기 전에 java-baseball-precourse/README.md 파일에 구현할 기능 목록을 정리해 추가한다.
 - git의 commit 단위는 앞 단계에서 README.md 파일에 정리한 기능 목록 단위로 추가한다.
   - [AngularJS Commit Message Conventions](https://gist.github.com/stephenparish/9941e89d80e2bc58a153) 참고해 commit log를 남긴다.
+- [프리코스 과제 제출 문서](https://github.com/woowacourse/woowacourse-docs/tree/master/precourse) 절차를 따라 미션을 제출한다.
 
 <br>
 
diff --git a/build.gradle b/build.gradle
index 95687b5..56b3bc8 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,19 +1,19 @@
-plugins {
-    id 'java'
-}
+apply plugin: 'java'
+apply plugin: 'eclipse'
 
-group 'org.example'
-version '1.0-SNAPSHOT'
+version = '1.0.0'
+sourceCompatibility = 1.8
 
 repositories {
     mavenCentral()
 }
 
 dependencies {
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
+    testImplementation('org.junit.jupiter:junit-jupiter:5.7.0')
+    testImplementation('org.assertj:assertj-core:3.18.1')
+    testImplementation('org.mockito:mockito-inline:3.6.0')
 }
 
 test {
     useJUnitPlatform()
-}
\ No newline at end of file
+}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index be52383..8de3c30 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,9 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+<<<<<<< HEAD
 distributionUrl=https\://services.gradle.org/distributions/gradle-6.7-bin.zip
+=======
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-bin.zip
+>>>>>>> 2d75f4343ccfdead02994a6674392d6353b04a19
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 4f906e0..1960262 100755
--- a/gradlew
+++ b/gradlew
@@ -1,21 +1,5 @@
 #!/usr/bin/env sh
 
-#
-# Copyright 2015 the original author or authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
 ##############################################################################
 ##
 ##  Gradle start up script for UN*X
@@ -44,7 +28,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
@@ -82,7 +66,10 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+<<<<<<< HEAD
 
+=======
+>>>>>>> 2d75f4343ccfdead02994a6674392d6353b04a19
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -126,11 +113,10 @@ if $darwin; then
     GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
-# For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath
@@ -156,19 +142,19 @@ if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
         else
             eval `echo args$i`="\"$arg\""
         fi
-        i=`expr $i + 1`
+        i=$((i+1))
     done
     case $i in
-        0) set -- ;;
-        1) set -- "$args0" ;;
-        2) set -- "$args0" "$args1" ;;
-        3) set -- "$args0" "$args1" "$args2" ;;
-        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
 fi
 
@@ -177,9 +163,14 @@ save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
-APP_ARGS=`save "$@"`
+APP_ARGS=$(save "$@")
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
 eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
 
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index 107acd3..6d57edc 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,19 +1,3 @@
-@rem
-@rem Copyright 2015 the original author or authors.
-@rem
-@rem Licensed under the Apache License, Version 2.0 (the "License");
-@rem you may not use this file except in compliance with the License.
-@rem You may obtain a copy of the License at
-@rem
-@rem      https://www.apache.org/licenses/LICENSE-2.0
-@rem
-@rem Unless required by applicable law or agreed to in writing, software
-@rem distributed under the License is distributed on an "AS IS" BASIS,
-@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@rem See the License for the specific language governing permissions and
-@rem limitations under the License.
-@rem
-
 @if "%DEBUG%" == "" @echo off
 @rem ##########################################################################
 @rem
@@ -29,18 +13,15 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
-@rem Resolve any "." and ".." in APP_HOME to make it shorter.
-for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
-
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if "%ERRORLEVEL%" == "0" goto init
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -54,7 +35,7 @@ goto fail
 set JAVA_HOME=%JAVA_HOME:"=%
 set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
-if exist "%JAVA_EXE%" goto execute
+if exist "%JAVA_EXE%" goto init
 
 echo.
 echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
@@ -64,14 +45,28 @@ echo location of your Java installation.
 
 goto fail
 
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
 :execute
 @rem Setup the command line
 
 set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
-
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
 
 :end
 @rem End local scope for the variables with windows NT shell
diff --git a/src/main/java/baseball/Application.java b/src/main/java/baseball/Application.java
index d484dad..df54e3a 100644
--- a/src/main/java/baseball/Application.java
+++ b/src/main/java/baseball/Application.java
@@ -4,7 +4,16 @@
 
 public class Application {
     public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-        // TODO 구현 진행
+        final Scanner scanner = new Scanner(System.in);
+        GamePlayer gamePlayer = new GamePlayer();
+
+        //게임 시작
+        while(true){
+        gamePlayer.play(scanner);
+        System.out.println("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.");
+        if(scanner.nextInt()==1)
+            continue;
+        break;
+        }
     }
 }
diff --git a/src/main/java/baseball/GamePlayer.java b/src/main/java/baseball/GamePlayer.java
new file mode 100644
index 0000000..7a9972c
--- /dev/null
+++ b/src/main/java/baseball/GamePlayer.java
@@ -0,0 +1,36 @@
+package baseball;
+
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+import static baseball.Number.*;
+
+public class GamePlayer {
+
+    public static void play(Scanner Input){
+        Number random = new Number();
+        Number player = new Number();
+        Integer temp;
+
+        //랜덤 수 생성
+        random.setNumber(random.createNumber());
+
+        //게임 내 n트
+        while(true) {
+            //입력 받고 비정상적인 입력 처리하고 저장
+            System.out.print("숫자를 입력해 주세요 : ");
+            try {
+                temp = Input.nextInt();
+            }catch (InputMismatchException e) {
+                throw new IllegalArgumentException("올바른 입력이 아닙니다!");
+            }
+
+            inputCheck(temp);
+            player.setNumber(splitNumber(temp));
+
+            Referee referee = new Referee();
+            if (referee.judgement(random.getNumber(), player.getNumber()))
+                break;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/baseball/Number.java b/src/main/java/baseball/Number.java
new file mode 100644
index 0000000..1978333
--- /dev/null
+++ b/src/main/java/baseball/Number.java
@@ -0,0 +1,75 @@
+package baseball;
+
+
+import utils.RandomUtils;
+
+import java.util.ArrayList;
+
+public class Number {
+    private ArrayList<Integer>  number;
+
+    public ArrayList<Integer>  getNumber() {
+        return number;
+    }
+
+    public void setNumber(ArrayList<Integer> playerNumber) {
+        this.number = playerNumber;
+    }
+
+    //임의의 수 3개 생성
+    public static ArrayList<Integer>  createNumber(){
+        ArrayList<Integer> result = new ArrayList<>();
+        int temp;
+
+        //중복 수 제거
+        for(int i = 0 ; i<3; i++) {
+            temp = RandomUtils.nextInt(1, 9);
+
+            if (!result.contains(temp))
+                result.add(temp);
+            else
+                i--;
+        }
+        return result;
+    }
+
+    //입력받은 수 배열로 변환
+    public static ArrayList<Integer> splitNumber(Integer playerNumber) {
+        ArrayList<Integer> splitPlayerNumber = new ArrayList<>();
+        for (int i = 0; i < 3; i++) {
+            splitPlayerNumber.add(0, playerNumber % 10);
+            playerNumber /= 10;
+        }
+        return splitPlayerNumber;
+    }
+
+    //비정상적인 입력 처리
+    public static void inputCheck(Integer number){
+        is_Include_Zero(splitNumber(number));
+        is_Not_ThreeDigits(number);
+        is_overlap(splitNumber(number));
+    }
+
+    //세자리 수가 아닐 경우
+    public static void is_Not_ThreeDigits(Integer number){
+        if(number.toString().length()!=3)
+            throw new IllegalArgumentException("올바른 입력이 아닙니다!");
+    }
+
+    //중복일 경우
+    public static void is_overlap(ArrayList<Integer> number){
+        ArrayList<Integer> temp = new ArrayList<>();
+
+        for(int i = 0 ; i< 3; i++){
+            if(temp.contains(number.get(i)))
+                throw new IllegalArgumentException("올바른 입력이 아닙니다!");
+            temp.add(number.get(i));
+        }
+    }
+
+    //0이 입력될 경우
+    public static void is_Include_Zero(ArrayList<Integer> number){
+        if(number.contains(0))
+            throw new IllegalArgumentException("올바른 입력이 아닙니다!");
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/baseball/Referee.java b/src/main/java/baseball/Referee.java
new file mode 100644
index 0000000..dd66d7d
--- /dev/null
+++ b/src/main/java/baseball/Referee.java
@@ -0,0 +1,56 @@
+package baseball;
+
+import java.util.ArrayList;
+
+public class Referee {
+    private int strike;
+    private int ball;
+
+    public Referee(){
+        this.strike = 0;
+        this.ball = 0;
+    }
+
+    public boolean judgement(ArrayList<Integer> randomNumber, ArrayList<Integer> playerNumber){
+        count_Strike(randomNumber, playerNumber);
+        count_Ball(randomNumber, playerNumber);
+
+        if(this.strike==3) {
+            System.out.print("3스트라이크\n3개의 숫자를 모두 맞히셨습니다! 게임 종료");
+            return true;
+        }
+        if(this.strike != 0 && this.ball != 0)
+            System.out.println(this.ball + "볼 " + this.strike + "스트라이크");
+        else if(this.strike == 0 && this.ball != 0)
+            System.out.println(this.ball + "볼");
+        else if(this.strike != 0 && this.ball == 0)
+            System.out.println(this.strike + "스트라이크");
+        else{
+            System.out.println("낫싱");
+        }
+        return false;
+    }
+
+    public int count_Strike(ArrayList<Integer> randomNumber, ArrayList<Integer> playerNumber){
+        for(int i = 0 ; i < 3; i++){
+            this.strike += is_equals(randomNumber.get(i), playerNumber.get(i));
+        }
+        return this.strike;
+    }
+
+    public int count_Ball(ArrayList<Integer> randomNumber, ArrayList<Integer> playerNumber){
+        for(int i = 0; i < 3; i++){
+            for(int j = 0; j < 3; j++){
+                this.ball += is_equals(randomNumber.get(i), playerNumber.get(j));
+            }
+        }
+        this.ball -= this.strike;
+        return this.ball;
+    }
+
+    public int is_equals(int randomNumber, int playerNumber){
+        if(randomNumber==playerNumber)
+            return 1;
+        return 0;
+    }
+}