Rule 1: The game board is a 9x9 grid, divided into nine 3x3 grids. Your goal is to win three 3x3 grids in a row, column, or diagonal.
Rule 2: Players take turns placing their X or O on an empty space within a 3x3 grid.
Rule 3: Winning a 3x3 grid works exactly like regular Tic-Tac-Toe: get three of your marks in a row (horizontally, vertically, or diagonally). Once a grid is won, it becomes filled entirely with the winner's mark and cannot be played in anymore.
Rule 4: The tricky part: Your opponent's move dictates where you must play next. If your opponent places their mark in the top-right corner of a 3x3 grid, you MUST place your next mark in the top-right 3x3 grid on the larger 9x9 board.
Rule 5: If your opponent sends you to a 3x3 grid that has already been won or is full, you are free to play your mark in any empty space on any available 3x3 grid. Strategy is key!

Action: Use the left mouse button to select an empty space and place your piece.
Action: On a touchscreen device, tap the empty space where you want to place your piece.
Action: Think carefully before you place your piece! You cannot undo a move.

Yes, Ultimate Tic Tac Toe typically offers single-player modes against varying difficulty levels of AI.

Absolutely! Most versions allow for local multiplayer, where you can take turns on the same device.

Some versions may have a timer option, but standard Ultimate Tic Tac Toe focuses purely on strategy without time constraints.