Hex is a two player abstract strategy board game in which players attempt to connect opposite sides of a rhombus-shaped board made of hexagonal cells. Hex was invented by mathematician and poet Piet Hein in 1942 and later rediscovered and popularized by John Nash. It is traditionally played on an 11×11 rhombus board, although 13×13 and 19×19 boards are also popular. The board is composed of hexagons called cells or hexes. Each player is assigned a pair of opposite sides of the board, which they must try to connect by alternately placing a stone of their color onto any empty hex. Once placed, the stones are never moved or removed. A player wins when they successfully connect their sides together through a chain of adjacent stones. Draws are impossible in Hex due to the topology of the game board. Despite the simplicity of its rules, the game has deep strategy and sharp tactics. It also has profound mathematical underpinnings. The game was first published under the name Polygon in the Danish newspaper Politiken on December 26, 1942. It was later marketed as a board game in Denmark under the name Con-tac-tix, and Parker Brothers marketed a version of it in 1952 called Hex; they are no longer in production. Hex can also be played with paper and pencil on hexagonally ruled graph paper. Game type Hex is a finite, 2-player perfect information game, and an abstract strategy game that belongs to the general category of connection games. It can be classified as a Maker-Breaker game, a particular type of positional game. Since the game can never end in a draw, Hex is also a determined game. Hex is a special case of the "node" version of the Shannon switching game. Hex can be played as a board game or as a paper-and-pencil game. Rules Hex is played on a rhombic grid of hexagons, typically of size 11x11, although other sizes are also possible. Each player has an allocated color, conventionally Red and Blue or Black and White. Each player is also assigned two opposite board edges. The hexagons on each of the four corners belong to both adjacent board edges. The players take turns placing a stone of their color on a single cell on the board. The most common convention is for Red or Black to go first. Once placed, stones are not moved, replaced, or removed from the