Although it has been shown that no one can ever win at Tic Tac Toe unless a player commits an error, the game still seems to have a universal appeal. While it is
true that the number of moves is very large, there are really only a few basic patterns (because of symmetry). In fact, we will see that there are only 12
essentially different games.
In the language of Game Theory, Tic Tac Toe is a two-person contest that is finite (comes to an end), has no element of chance, and is played with "perfect information"
(all moves being known to both players).
My intent is to show you how it is impossible to lose at Tic Tac Toe, no matter whether you go first or second. If both players understand how to play, then there
will never be a winner. I have shown how to play the 12 essentially different Tic Tac Toe games.
Click here for a worksheet explaining Tic Tac Toe.
Click here for the answer key to Tic Tac Toe.