Rules

You are playing on 3x3 big board

1

Each square in the big board contais one small board

2

To win the game, you need to win three small boards in a line

3

By making step in the small square, you determine which small board will be available for your opponent's step

If the small board, in which your opponent should make a step, has no free squares, he could make a step in any free square

Example

If you make a step in the right bottom squere in the top left small board, your opponent should make a step in the right bottom small board

4

Your opponent make a step in the top center square, so you could make a step in the top center small board

5

Have fun!

For more info see this blog article