Every cell of the big board hides a small tic-tac-toe. Seat 1 draws ×, Seat 2 draws ○. Take turns. The first move can go anywhere. Online, each seat shows the player's name.
The cell you play sends your opponent to that board on the big gridThree in a row on a small board wins that boardA won or full board is closed. Sent there, you may pick any open boardA full board with no three in a row is shared
Line up the small boards you have won, and you win. If every board is finished and nobody has a line, the one who won more boards wins.
Where it comes from, and questions to think about
In Ben Orlin's Math Games with Bad Drawings this game is called ultimate tic-tac-toe. The name the author likes best is fractal tic-tac-toe. Why would tic-tac-toe have anything to do with fractals?Ultimate Tic-Tac-Toe, Math with Bad Drawings
Questions strong players ask
If I play here, which small board does my opponent get sent to?
A closed board lets them choose any open one. Do I want to give them that freedom?
If I fill this small board and it becomes shared, whose line does that help?