Copyright (c) 1980s David Balmer Jr.
This game is played on an empty 10x10 square board:
The green dots denote the cells owned by White, while the red dots denote those owned by Black. If Black drops a stone at cell , the unowned cell e5 will belong to Black, since there would be two black stones, against one white, adjacent to e5.
More information can be found at Mark Thompson's website.