Pests is an abstract strategy board game played by two or more players on a finite rectangular grid (most often a sheet of paper). The rules depend on the size of grid and a number of pests per turn m (two common variants are (10x10,3) and ("the whole sheet",5-10)).
Players alternate their moves. On the first turn the player puts m "pests" from his corner of the board (players choose opposite corners. If there are more than two players, starting positions can be different). Each new pest should be adjacent to the others (by side or by diagonal). On the next turns the following actions can be performed:
- Create a new pest adjacent to existing pest (or base, see below).
- Eat the opposing pest adjacent to your pest or base. The occupied cell becomes a "base" of the player who was attacking. To function the base must have an adjacent pest of that player or a functioning base of that player (they combine into a larger base). The functioning base works like pest for creating new pests or eating opponent's pests. The base can't be eaten.
Exactly m actions should be performed.
The game ends when:
- Only one player has pests - in which case he is the winner.
- There are no valid moves. It may happen when both players have a pest surrounded by his own base. These pests would never be eaten. In that case the game could end as a draw, or the player with the most territory can be declared a winner.