Tic-Tac-Toe Puzzles (and the Difference Between a Puzzle and a Game)

I’m still stunned by the response to my post on Ultimate Tic-Tac-Toe, which spawned a whole fleet of mobile apps, was translated into Spanish by the Argentine Department of Education, and has drawn more than half a million visitors.

I take no credit. I didn’t invent this game, just drew some silly pictures explaining it.

In response, commenters suggested lots of other variants on Tic-Tac-Toe. They ranged from well-known to obscure, from simple to complex, from fun to “I guess somebody must find this fun.” I’ll post someday about the variants that make good games. But this is a post about the ones that make good puzzles, and why “puzzle” isn’t the same as “game.”

Puzzle #1: Tic-Tac-Toe with No Starting Grid

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Ultimate Tic-Tac-Toe

Updated 7/16/2013 – See Original Here

Once at a picnic, I saw mathematicians crowding around the last game I would have expected: Tic-tac-toe.

As you may have discovered yourself, tic-tac-toe is terminally dull. There’s no room for creativity or insight. Good players always tie. Games inevitably go something like this:

But the mathematicians at the picnic played a more sophisticated version. In each square of their tic-tac-toe board, they’d drawn a smaller board:

As I watched, the basic rules emerged quickly. Continue reading