It has subsequently been studied by Elwyn Berlekamp and Erik Demaine among others.
It is typically played on a rectangular white and black checkerboard.
To start the game, each of the squares on the checkerboard is occupied by a stone.
The player who, on their turn, is unable to move, loses the game.
Another variant, also proposed by Ingo Althoefer in 2015, is San Jego: Here the pieces are not clobbered, but stacked to towers.