Trihex

Equitable version of tic-tac-toe on a triangular field and nine lines.

Trihex is a game in which you must occupy three rings of the same color in a straight line. Our mission is reminiscent of the traditional game, although in this case, you must place your pieces on a prism-shaped playing field comprised of nine rings arranged in nine lines.

At the start of the game, the triangular Trihex board will appear empty, with four pieces on each side. The lighter ones are yours, and the darker ones are your opponent's. To start playing, you must not only keep track of your own moves, but also those of your opponent, as you try to prevent them from lining up their three pieces before you do.

The game mechanics are simple, as you only need to tap on the spot on the prism where you want to place your ball. Your opponent's balls will automatically appear after each of your moves. With Trihex, we'll have fun while trying to strategically connect three pieces of our color in the same straight line, making it a practically addictive and fun game.

Thomas H. O'Beirne of Glasgow, author of Puzzles and Paradoxes (Oxford, 1965), experimented with topologically distinct nine-row models to see which ones were suitable for a game of tic-tac-toe. He found that in all regular configurations, the starting player can easily win. The only exception is the configuration shown here.