Hex - Rules, History & Strategy Guide

Hex was invented twice, independently: first by the Danish poet and scientist Piet Hein in 1942, who introduced it as Polygon in a Copenhagen newspaper, and again by mathematician John Nash at Princeton in 1948. Nash proved that the first player can always win with perfect play, and the game became a fixture of game theory and recreational mathematics.

Part of Hex’s fame is a beautiful theorem: a completely filled board always contains exactly one winning connection, so the game can never end in a draw. Easy to explain and impossible to exhaust, Hex has been used to teach topology and strategy for decades, and it remains a benchmark problem for game-playing AI.

You play red on an 11×11 rhombus of hexagons and win by connecting the left and right edges; the AI plays blue and connects top to bottom.

1. Take turns placing a single stone on any empty hexagon.
2. As red, build an unbroken chain of red hexes joining the left edge to the right edge.
3. The AI, as blue, tries to connect the top edge to the bottom edge.
4. Stones never move and are never captured once placed.
5. The first player to complete their edge-to-edge connection wins — and because a full board always has exactly one connection, there are no draws.

• Play toward the centre early; central stones touch more potential paths in both directions.
• Learn the bridge — two stones with two shared empty cells between them are virtually connected because the opponent cannot cut both.
• Remember that every connecting move also blocks your opponent; attack and defence are the same act.
• Build toward your own edges early rather than leaving the final link to a crowded endgame.
• Judge positions by who is closer to connecting, not by counting stones — material is meaningless in Hex.

Board sizes range from a gentle 7×7 up to 19×19 for experts; 11×11 and 13×13 are tournament standards. The “swap” (pie) rule is often used to offset the first-player advantage: the second player may steal the opening move. Variants like Y, Havannah, and TwixT extend the same connection idea in new shapes.