Anadil

Introduction:Anadil (from Middle Welsh: anadyl, meaning "breath") is a drawless territorial game for two players: Black and White. It is played on the intersections (points) of a initially empty square board. The recommended board size is 15 points per side, but boards of 11, 13, 17 or 19 are also valid. There is also a location outside the board called prison. Each player has access to a sufficient supply of stones of their own color.

This game is based on Anda.

Definitions:

A group is a maximal set of stones of the same color connected orthogonally. A single stone is also a group.

A supergroup is a maximal set of groups of the same color connected diagonally. A single group is also a supergroup.

A breath of a supergroup is a maximal set of orthogonally or diagonally connected points that does not include points occupied by the supergroup.

A group is smothered if all breaths in its supergroup have at least one path to exactly one enemy supergroup, and that supergroup is the same for all breaths in that group. The path must be composed of orthogonally or diagonally connected empty points, can be of length zero, and need not be a straight line.

Turns:Black plays first, and then players alternate. On your turn, perform these actions in the following order:

Place a stone of your color on an empty point, then move all smothered enemy groups to the prison, followed by moving all smothered friendly groups to the prison. If it is your first turn, place two stones of your color on empty cells on opposite edges.

Remove an enemy stone from the prison. If the prison contains stones of both colors, remove pairs of stones of opposite colors until only stones of one color remain or none remain.

At the end of your turn, the placed stone may not create a new group unless it changes the board state, and the group of the placed stone cannot smother a group that, in the previous turn, had smothered exactly all of your groups. For better visual clarity, although capturing is mandatory, it is recommended that beginners start playing with optional captures.

End of the game:The last player to perform an action wins.

To balance the game, before starting, the first player places a number of black stones in the prison, and then the second player chooses a side. For handicap games, the weaker player chooses black and begins by placing a number of stones in the prison proportional to the difference in skill between the players. This balancing method is called the komi pie rule.