An abstract game: the 13 red pins are the prisoners, 4 black pins are the wardens. Wardens (starting on each of the four corners of the 8 x 8 board) have to capture the prisoners by jumping over them - if only 3 red pins are remaining, the game is won by the warden player. The red pins try to reach all 4 corner spaces (which is their victory condition). A warden cannot be eliminated, but is forced to jump over a red pin, if possible.