Martian Chess

Martian Chess was a complicated form of chess with seventy-two pieces on the board, including Lords, Priests, Princesses, Captains, and Duchesses.

Barbara Wright and Vicki Pallister played a game before the the TARDIS landed in Palestine during the crusades. On the First Doctor's advice, Vicky captured Barbara's Lord, bringing up her Priest in order to marry her Princess to an opposing Lord. This prevented Barbara from marrying a Captain to Vicki's Duchess, making her lose a dowry. (PROSE: Doctor Who and the Crusaders)