Definitions

A 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 smothered group is a group without liberties.

Play

Black plays first, then turns alternate. At the start of your turn, you will face one of these situations:

• There are no smothered friendly groups. In this case, you must place a stone of your color on an empty point. Your placement must not increase the number of smothered friendly groups unless it also increases the number of smothered enemy groups.

• There are one or more smothered friendly groups. In this case, you must move one stone from one of those groups to an empty point such that, after the move, the group that now includes the moved stone has at least one liberty. You may only move a stone from a point where it is orthogonally adjacent to one or more enemy stones.

If you have no moves available on your turn, you lose. Draws are not possible.

To make the game fair, White will have the option, on their first turn only, to swap sides with Black instead of making a regular move.