Tic-Tac-Toe is a two-player game played on a 3X3 grid where players alternate placing 'X' or 'O' in an empty space in the grid. The first player to lineup three marks in a row, column, or diagonal wins. X goes first, players alternate turns, and only one player can have a winning line (or no one). If a player has won, the game ends immediately, and no more moves can be made. considering players 3x3 = 9 X has 5 moves. O has 4 moves.