The objective of the game is to win three grids in a row.
To win a grid, you must get three of your symbols in a row.
Your opponent must play in the grid that corresponds with the space you just played in. For example, if you play in the top right space of a grid, your opponents next move must be in the top right grid.
If the grid corresponding with the space you played in is no longer playable, your opponent can play in any open space.