Il Vaticano is a fictional chess move that originated as an inside joke on the r/AnarchyChess subreddit. It depicts a scenario where two bishops on the same rank can jump over adjacent pieces to capture them or create a unique board state, mimicking the absurdity of other chess memes like En Passant. The meme gained traction in late 2022 and early 2023, often presented as a legitimate but obscure rule to confuse newcomers or mock traditional chess theory. It exemplifies the subreddit's chaotic humor, where users invent increasingly complex and nonsensical rules to parody the rigidity of grandmaster-level play.