Hex is a
strategy board game played on a
hexagonal grid, theoretically of any size and several possible shapes, but traditionally as an 11×11
rhombus. Other popular dimensions are 13×13 and 19×19 as a result of the game's relationship to the older game of
Go. According to the book
A Beautiful Mind,
John Nash (one of the game's inventors) advocated 14×14 as the optimal size.