Twenty Squares

From Biblical Archaeological Review Strata Gallery:

A graffito version of the Royal Game of Ur, the “game of 20 squares.” This improvised board was scratched—possibly by bored soldiers—onto one of the human-headed winged bull gate sentinels from the palace of Sargon II (721–705 B.C.) in the city of Khorsabad, Iraq. Other improvised game boards have recently been discovered on the surfaces of other ancient structures.(Courtesy WikiMedia)