4D Tic-Tac-Toe

https://web.uvic.ca/~tbazett/tictactoe.html

Play 2D, 3D, and 4D Tic-Tac-Toe with 2+ players and 2+ symbols. A branch of mathematics called Ramsey Theory tells us that in high enough number of dimensions you are guaranteed to have a winner regardless of the number of players or symbols.