Play with 2 people (on the same device) Have one person play as X, one as O When the "turn" marker in the top-left is your symbol, click one of the highlighted squares (light red) to put your symbol on. After you play your X/O, the "mini-board" your opponent plays on is the location of the square YOU played on. (Example: if I play on the top-right square, my opponent must play on the top-right mini-board) Three in a row on a mini-board wins that mini-board, and three mini-boards in a row wins the game. If you send your opponent to a mini-board that has already been won, they may move anywhere. On the first move X can move anywhere. Doing 2 moves right after each other may break the code.
The book "math games with bad drawings" by Ben Orlin where I learned this game from
