I have created a logical AI for tic-tac game , i want a review about how good or bad it is . Here the computer AI will defend all your attacks as well as try to attack whenever it gets a chance . Below is the code you can directly try running it . import java.util.Random; import java.util.Scanner; public class TicTac { static { System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t ________________________ _______________________"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t |___ ___|___ ___| ____| |___ ___| _ | ____|"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t | | | | | | ____ | | | |_| | |"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t | | | | | | |____| | | | _ | |"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t | | __| |__| |___ | | | | | | |___"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t |__| |________|______| |__| |__| |__|______|"); System.out.println("\n\n"); } private Scanner sc = new Scanner(System.in); private char board[] = new char[9]; private char turn = 'X'; private Random random = new Random(); private int winX = 0; private int winO = 0; private String name; private char myChoice = 'O'; public static void main(String[] args) { TicTac t = new TicTac(); int numberOfGames = 1; long start, end; start = System.currentTimeMillis(); do { t.play(); numberOfGames--; System.out.println("\t\t\t\t\t\t\t\t\t\t\t----------------------------------------------------------------"); } while (numberOfGames > 0); end = System.currentTimeMillis(); System.out.println("\n\t\t\t\t\t\t\t\t\t\t\tTime taken by the program to execute is : " + (end - start)); } private void playersTurn() { int r; boolean check = false; do { System.out.println("\n\n\t\t\t\t\t\t\t\twhere do you wnt to play , select from 1 - 9 :"); try { r = getChoice(); if (!(r > 0 && r < 10)) { Thread.sleep(1000); throw new NumberFormatException("Invalid Number"); } r -= 1; if (board[r] == ' ') { board[r] = turn; check = true; } else if (board[r] == myChoice) { System.out.println("you already played there"); } else { System.out.println("computer played there"); } } catch (Exception e) { System.out.println("invalid choice. \t " + e); } } while (!check); } private int getChoice() { String x = "1"; try { x = sc.nextLine(); if (x.matches("^[1-9]$")) { } else { throw new NumberFormatException("Invalid Number"); } } catch (Exception e) { System.out.println(e.getMessage()); } return Integer.parseInt(x); } private void initializeBoard() { for (int i = 0; i < 9; i++) { board[i] = ' '; } } private void switchPlayer() { if (turn == 'X') { turn = 'O'; } else if (turn == 'O') { turn = 'X'; } } private boolean win() { for (int i = 0; i < 9; i++) { if (board[i] == ' ') { board[i] = turn; if (checkWin()) { return true; } else { board[i] = ' '; } } } return false; } private void attack() { boolean check = false; do { int r = random.nextInt(9); if (r == 1 || r == 3 || r == 5 || r == 7 || r != 4) { r = random.nextInt(9); } if (board[r] == ' ') { board[r] = turn; check = true; } } while (!check); } private boolean defence() { switchPlayer(); for (int i = 0; i < 9; i++) { if (board[i] == ' ') { board[i] = turn; if (checkWin()) { switchPlayer(); board[i] = turn; return true; } else { board[i] = ' '; } } } switchPlayer(); return false; } private boolean filled() { for (int i = 0; i < 9; i++) { if (board[i] == ' ') { return false; } } return true; } private void play() { initializeBoard(); do { if (win()) { switchPlayer(); } else if (defence()) { switchPlayer(); } else { attack(); switchPlayer(); } display(); if (turn == myChoice && !checkWin() && !filled()) { playersTurn(); switchPlayer(); display(); } /*try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); }*/ System.out.println("\n"); } while (!filled() && !checkWin()); if (checkWin()) { switchPlayer(); if (turn == 'O') { winO++; } else { winX++; } System.out.println(); display(); System.out.println("\n"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t " + turn + " has won"); } else { System.out.println(); display(); System.out.println("\n"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t game is draw... "); } } private boolean checkWin() { return (board[0] == board[1] && board[1] == board[2] && board[0] != ' ' || board[3] == board[4] && board[4] == board[5] && board[3] != ' ' || board[6] == board[7] && board[7] == board[8] && board[6] != ' ' || board[0] == board[4] && board[4] == board[8] && board[0] != ' ' || board[2] == board[4] && board[4] == board[6] && board[2] != ' ' || board[0] == board[3] && board[3] == board[6] && board[0] != ' ' || board[1] == board[4] && board[4] == board[7] && board[1] != ' ' || board[2] == board[5] && board[5] == board[8] && board[2] != ' '); } private void display() { System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t " + board[0] + " | " + board[1] + " | " + board[2] + " PLAYER 'O' | CPU 'X'"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t---|---|--- ---------|---------"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t " + board[3] + " | " + board[4] + " | " + board[5] + " |"); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t---|---|---" + "\t \t\t\t\t" + winO + "\t|\t" + winX); System.out.println("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t " + board[6] + " | " + board[7] + " | " + board[8] + " |"); } }