Everyone over the age of 7 gets bored playing regular tic tac toe. But take a look at this!
Mega-Ultra Tic Tac Toe, Supreme Tic Tac Toe, Meta Tic Tac Toe.
Have you ever played it? I got it from Math with Bad Drawings years ago and surprisingly there are still people who have never heard of it. (Don’t say it’s because it’s not fun. It’s fun.) His description is awesome so go there and check it out. I’ll do a quick overview.
The goal is to win the large tic tac toe board by winning the small boards.
If you win a small board, that square gets a giant O or X on it. Like this:
The catch is that you don’t get to play any board you want.
Let’s say X plays in the top left board to start and choose the bottom right square. Whatever square X picks is where (on the larger board) O must play:

And so on. So if O now chooses the center square, X must place somewhere on the center board. Get it?
Try it. It’s mind-bending.