The Classic Game of 15

A game of Tic-Tac-Toe disguised with numbers. Be the first to collect three numbers that sum to 15.

Choose your challenge: learn the magic square or play the strategic game.

Strategy Guide: The Tic-Tac-Toe Secret

The 'Sum to 15' game is a clever disguise for Tic-Tac-Toe. Every winning combination of three numbers corresponds to a winning line on a Tic-Tac-Toe board. The number 5 is the center square, the even numbers (2, 4, 6, 8) are the corners, and the remaining odd numbers (1, 3, 7, 9) are the sides. Seizing the center (5) and controlling the corners gives you a strategic advantage, just like in Tic-Tac-Toe!