HeXO

HeXO is a two-player abstract strategy game played on an infinite hexagonal grid. It was introduced by webgoatguy in March 2026 as a hexagonal version of tic-tac-toe. Instead of making three in a row, players aim to connect six or more cells in a row.

Gameplay

The first player places one piece at the origin. The second player then places two pieces, and play continues with two placements per turn. A piece may only be placed on an empty hex.

The game ends as soon as either player connects six of their pieces in a straight line. The hexagonal board has three axes, so a winning line may be horizontal or run along either diagonal.

HeXO can be played online at hexo.did.science.
Grab a friend and play against them, or play against a bot using sandbox mode.

See the rules for further information.

Strategy

Having two placements per turn makes HeXO quite different from ordinary tic-tac-toe. A player can extend two lines, block in two places, or defend with one piece while starting an attack with the other.

Much of the game's vocabulary comes from these situations. A threat is a position that can win on the next turn. Lines are described as open when both ends are free, closed when one end is blocked, and dead when neither end can be extended. Players also study tempo, distant colonies, formations, and named openings.

History and study

The game quickly attracted a small community of players, programmers, and game theory enthusiasts. They developed notation systems, opening catalogues, board explorers, and bots. The community's work is collected in several living theory documents.

See further reading or join the HeXO Discord for more information.

Community

Join the comunity HeXO Discord.