Tic Tac Toe description

Tic-Tac-Toe is a classical paper-and-pencil game for 2 players. You were probably used to play Tic-Tac-Toe game during your childhood. The rules are quite simple : each player sets a X or O on a 3x3 grid. The player who succeeds in placing three of their marks in a horizontal, vertical, or diagonal row wins the game.