Tic Tac Toe Master supports one and two player gameplay and (3-20/3-20 grid). Tic-tac-toe (also known as Noughts and crosses or Xs and Os) is a paper-and-pencil game for two players, X and O, who take turns marking the spaces in a 3-20/3-20 grid. The player who succeeds in placing (n) of their marks in a horizontal, vertical, or diagonal row wins the game.