Crossings (game)

Crossings is a two-player abstract strategy board game invented by Robert Abbott. The rules were published in Sid Sackson's "A Gamut of Games". Crossings was the precursor to Epaminondas, which uses a larger board and expanded rules.
Gameplay.
Setup.
This is the starting position of Crossings.
Movement.
A "group" is a series of one or more same-colored stones adjacent to one another in a line. (diagonal, horizontal, or vertical) A stone may belong to one or more groups.