Sligo

"Sligo is a territory game for two players: Black and White. It is played on the intersections (points) of an initially empty square grid (board). There is also an off-board location called prison. Sligo is based on Corey Clark's Slither and the ancient game of Go. DefinitionsA group is a stone along with all stones one can reach from it through a series of steps onto orthogonally adjacent stones of its color. A liberty of a group is an empty point orthogonally adjacent to it. A group without liberties is said to be dead. A naked diagonal is a pair of diagonally adjacent stones of the same color with no other stone of their color adjacent to both. PlayBlack plays first, then turns alternate. On your turn, perform exactly one of these actions: Remove an enemy stone from the prison. Place a friendly stone on an empty point, then move to the prison all dead enemy groups. If the prison now contains stones of both colors, remove pairs of opposite-colored stones from it until at most one color remains. Finally, if there are naked diagonals on the board, move a stone of your color to a diagonally adjacent empty point. At the end of your turn, there must be no naked diagonals and no dead friendly groups on the board. The last player to perform an action wins. If a play recreates any previous end-of-turn board position with the same player to move, the game ends in a draw. This is possible in theory, but probably requires colluding players. Before the game starts, to make it fair, the first player places a number of black stones in the prison, and then the second player chooses sides. "