I have made a rithmomachy board, also known as the philosophers game. The game can be described as "chess combined with number theory": https://en.wikipedia.org/wiki/Rithmomachy Unfortunately, all people that actually know how to play this game have died more than 400 years ago. ... or have they? Is there somebody with a rithmomachy board who is interested in playing a long-distance game? We could post the moves as pictures here so others can comment on our... creativity.