Which game dates back to at least the Roman Empire: Nine Men's Morris, or Icehouse pieces?
Nine Men's Morris Nine Men's Morris is a strategy board game for two players dating at least to the Roman Empire. The game is also known as Nine Man Morris, Mill, Mills, The Mill Game, Merels, Merrills, Merelles, Marelles, Morelles and Ninepenny Marl in English. The game has also been called Cowboy Checkers and is sometimes printed on the back of checkerboards. Nine Men's Morris is a solved game in which either player can force the game into a draw.
Ostomachion Ostomachion, also known as loculus Archimedius (Archimedes' box in Latin) and also as syntomachion, is a mathematical treatise attributed to Archimedes. This work has survived fragmentarily in an Arabic version and a copy, the Archimedes Palimpsest, of the original ancient Greek text made in Byzantine times. The word Ostomachion has as its roots in the Greek Ὀστομάχιον, which means "bone-fight", from ὀστέον ("osteon"), "bone" and μάχη ("mache"), "fight, battle, combat". Note that the manuscripts refer to the word as "Stomachion", an apparent corruption of the original Greek. Ausonius gives us the correct name "Ostomachion" ("quod Graeci ostomachion vocavere," "which the Greeks called ostomachion"). The Ostomachion which he describes was a puzzle similar to tangrams and was played perhaps by several persons with pieces made of bone. It is not known which is older, Archimedes' geometrical investigation of the figure, or the game. Victorinus, Bassus Ennodius and Lucretius have talked about the game too.