Play 4-Dimensional Tic Tac Toe here. Four Dimensional Tic-Tac-Toe takes longer to play than ordinary tictactoe and is much more challenging. Tic tac toe is also known as noughts and crosses or Xs and Os. The games on this site are called tictactoe because they are based on a grids of 3x3 squares. Playing 4-D tic-tac-toe can help to exercise your pattern recognition and short term memory skills. The activities of thinking ahead and of pattern recognition tasks can help to train your brain and help to counteract the ageing process or improve learning.