Rithmomachia

Rithmomachia, also spelled rithmomachy or arithmomachia and known descriptively as the philosophers' game, is an early European mathematical board game whose earliest surviving description dates from around the eleventh century, making it one of the oldest documented board games native to Western Europe. Its name derives loosely from Greek roots meaning the battle of the numbers, reflecting a game superficially similar to chess in that two players maneuver pieces across a rectangular board trying to capture the opponent's pieces, but fundamentally different in that captures and victory conditions depend on numerical relationships, such as ratios, sums, and proportions, inscribed on each piece rather than on simple contact or movement rules alone. The game is believed to have originated in monastic or cathedral school settings in what is now Germany or France, where it was used as a teaching tool for Boethian arithmetic and number theory, and it later spread to England and other parts of Europe, remaining an academic curiosity studied by mathematicians and game historians long after it fell out of common play.