How to Play Hex
Hex was invented twice: by Piet Hein in 1942 and by John Nash in 1948. The rules fit on a card, and the game is deep.
The rules
- The board is a rhombus of hexagons, 7, 9 or 11 on a side. Red owns the top and bottom edges, Blue the left and right.
- Red plays first. Players take turns placing one stone of their colour on any empty hexagon.
- Stones never move and are never captured.
- A player wins by completing a chain of their stones that touches both of their edges.
There is always a winner: a full board can't fail to connect one of the two sides.
The swap rule
The first player has a big advantage, so after Red's first stone Blue may swap: Red's stone becomes Blue's (mirrored across the long diagonal so that it serves Blue's direction), and Red moves next. Red should therefore open with a modest stone.
On kawu
- Tap a hexagon to place a stone. The winning chain lights up at the end.
- Three computer levels, two players on one device, or online with a room link (choose the board size when creating the room).
Frequently asked questions
Can Hex end in a draw?
No. Once the board is full, exactly one player has a connecting chain. That's a theorem: a full Hex board always has a winner.
What is the swap rule in Hex?
After Red's first stone, Blue may choose to take that stone over as Blue's own instead of playing. It stops Red from opening in the centre, which would otherwise be too strong.
Last updated 2026-10-20