Fun fact: at the very beginning of the evolution of the game, there was only one move - en passant. And the game was called 'en passant game'. 'En passant' comes from the old phoenician 'heēn pąšhãnn' meaning approximately 'en passant'.

The players would take turns doing en passant moves until ultimately no further move could be done, at which point the loser would be eviscerated and his entrails offered in sacrifice to Ba'al. Then everybody would discuss how the loser's opening sucked and how many blunders he did.