Tic-Tac-Toe is a kind of Lianzhu game on a 3 * 3 grid. It is similar to Gobang. Because the chessboard generally does not draw borders and the grid lines are arranged in well characters, it gets its name. The game only needs paper and pen, and then two players representing O and X leave marks in the grid in turn (generally speaking, the first one is x). If any three marks form a straight line, it is the winner.

Most people who have played Tic-Tac-Toe will find that if both players make the best choice, the game is bound to draw. Therefore, tic tac toe is most often used as a children's game.

Source: @tat_to_the_bone