What is Hex board sizes?
Hex works on a rhombus of any size, and the rules do not change with it. Red links the top and bottom edges, Blue links the left and right edges, and the first complete chain wins. Here you can pick any board from 7×7 to 19×19 in the table setup instead of the standard 11×11.
Size changes the character of the game. On a 7×7 or 9×9 board a game lasts a few minutes and every stone matters at once, which makes small boards a good place to learn the basic shapes such as the bridge and edge templates. On 13×13 and larger boards there is room for slow, strategic play: stones far from each other start to work together, and an early mistake can still be repaired.
The swap rule works at every size, and so does Rex, the reverse game in which linking your own edges loses.
Rule changes
| Rule | Standard Hex | Hex board sizes |
|---|---|---|
| Board | Standard HexAn 11×11 rhombus of 121 hexagonal cells. | Hex board sizesAny rhombus from 7×7 (49 cells) to 19×19 (361 cells), chosen in the table setup. |
| Shortest winning chain | Standard Hex11 stones, one in every row or column. | Hex board sizesAs many stones as the board has rows: 7 on 7×7, 19 on 19×19. |
| Game length | Standard HexA few dozen moves; at most 121 stones fit on the board. | Hex board sizesSmall boards take a few minutes. A 19×19 board holds 361 stones, and games last much longer. |
| Swap rule | Standard HexOn by default: after Red's first stone, Blue may take it over instead of placing a stone. | Hex board sizesThe same at every size, and it can be switched off in the table setup. |
| How to win | Standard HexBe the first to link your own two edges. Draws are impossible. | Hex board sizesThe same at every size: the first complete chain wins, and a full board always has a winner. |
History
Piet Hein presented the game in Denmark in 1942 under the name Polygon, on an 11×11 board, and 11×11 has been the standard size ever since. John Nash reinvented the game independently at Princeton in the late 1940s, where it was played on larger boards; Nash is said to have favoured 14×14. When the game was first sold commercially as Hex in 1952, it used 11×11 again.
Nash also proved that on a board of any size the first player has a winning strategy, but his proof does not say what that strategy is. The swap rule was adopted to remove that advantage, and finding the actual winning moves turned into a long computer project. Researchers at the University of Alberta solved every opening on 7×7 in 2003 and on 8×8 in 2009, and Jakub Pawlewicz and Ryan Hayward solved 9×9 in 2013. Boards of 11×11 and larger remain unsolved.
Today 11×11 and 13×13 are the usual sizes for competitive play and computer tournaments, while 19×19 offers a much longer game for players who want more room.