Map-coloring games

The advantages of this method are that only a small area need be marked on a turn, and that the representation usually takes up less space on the paper or screen.

The first advantage is less important when playing with a computer interface instead of pencil and paper.

The map-based constraints on a move are usually based on the region to be colored and its neighbors, whereas in the map-coloring problem, regions are considered to be neighbors when they meet along a boundary longer than a single point.

The classical map-coloring problem requires that no two neighboring regions be given the same color.

The misère play convention considers the last player to move to lose the game.

In "Bichrome" both players have a choice of two colors, subject to the classical condition.

The condition can be extended to any fixed number of colors, yielding further games.

The names are mnemonic for the difference in constraints (classical map coloring versus animal noises), but Conway also attributes them to his colleagues Colin Vout and Simon Norton.