Tic-tac-toe (Xs and Os) is a game for two players, who take turns marking the spaces in a 3×3 grid. The player who succeeds in placing three of their marks in a horizontal, vertical, or diagonal row wins the game. Rules: 1. The game is played on a grid that\'s 3 squares by 3 squares. 2. You are X, your friend (or the computer in this case) is O.