 Humorous variations to the rules have been introduced to games.Humphrey Lyttelton would describe special rules to apply to that session, such as "Trumpington's Variations" or "Tudor Court Rules", so that almost every episode featuring Mornington Crescent introduced a variant.In one of them, first introduced in North Yorkshire, a player whose movement is blocked is considered to be "in Nidd" and is forced to remain in place for the next three moves.