Tic-tac-toe, also called Noughts and crosses (in the UK, Australia, New Zealand, South Africa, India and the rest of the British Commonwealth countries), is a pencil-and-paper game for two players, X and O, who take turns marking the spaces in a 3×3 grid. The X player usually goes first. The player who succeeds in placing three respective marks in a horizontal, vertical, or diagonal row wins the game.
