The Rules

These rules assume you know how to play regular tic tac toe.

The Board

An ultimate tic tac toe board is made up of 9 regular sized tic tac toe boards, as shown below. Each regular sized tic tac toe board has 9 cells. I will refer to the location of these boards and cells using compass directions.

X's turn

Moving

The player who goes first gets to move anywhere on the board.

O's turn

In this case, X chose to move in the northwestern corner of one of the smaller boards. This means on the next turn, O is forced to move in the northwestern board. The board that O is forced to move in is outlined in blue-gray.

X's turn

O decided to move in the southern cell of the northwestern board. This forces X to move in the southern board on the following turn.

O's turn

Because X chose to move in the center cell, O now has to move in the center board.

By now you hopefully have a gist of how moving works in ultimate tic tac toe. There are some interesting strategies that come into play as a result of these rules. Let's fast forward a couple of turns.

X's turn

It is X's turn in the image above. At first glance, it seems tempting to move in the center cell, allowing X to win the eastern board.

O's turn

However, doing so sends O to the center board.

X's turn

This would allow O to win the center board, putting X at a disadvantage. Now, say X wishes to block O by moving in the center cell.

O's turn

Normally, O would be sent to the center board after X moved in the center cell. However, since the center board has already been won, O can now move anywhere on the board.

Winning

The game is won once one of the players gets three in a row.

O wins!