Ultimate Tic-Tac-Toe is played on a 3×3 grid of Tic-Tac-Toe boards (9 total boards). The goal is to win three small boards in a row on the large board.
First Move: The first player may place their mark in any square on any small board.
The Key Rule: The square you choose determines which board your opponent must play in next.
For example, if you play in the top-right square of a small board, your opponent must make their next move in the top-right board of the large grid.
A small board is won exactly like regular Tic-Tac-Toe:
If you are sent to a board that is already won or completely full, you may play in any open board on your turn.
Each small board counts as a square on the large board. To win the game, you must win three small boards in a row horizontally, vertically, or diagonally.
The game is a draw if no player has won three small boards in a row and there are no legal moves remaining.
You're not just deciding where to play—you’re also deciding where your opponent must play next. Sometimes it is worth sacrificing a small board to gain control of the larger board.