A joke chess problem is a puzzle in chess that uses humor as an element. Although most chess problems, like other creative forms, are appreciated for serious artistic themes (such as Grimshaw, Novotny, and Lacny), joke chess problems are enjoyed for some twist. In some cases the composer plays a trick to prevent a solver from succeeding with typical analysis. In other cases, the humor derives from an unusual final position. Unlike in ordinary chess puzzles, joke problems can involve a solution which violates the inner logic or rules of the game.