Knight (chess) king); in descriptive chess notation, "Kt" is sometimes used instead, mainly in older literature. In chess problems and endgame studies, the letter "S", standing for the German name for the piece, "Springer", is often used (and in some variants of fairy chess "N" is used for the popular fairy chess piece, the nightrider). Even among sets of the standard Staunton pattern, the style of the pieces varies. The knights vary considerably. Here are some examples. The knight, along with the king and the rook, has the oldest defined movement of any chess piece, its movement being unchanged since the invention
Fairy chess piece that must land immediately after first piece it encounters, instead of on or before it), pao (rider that can only land behind the first piece it encounters, instead of on or before it), o cylindrical (moving off one side of the board wraps to the other), z crooked (moving in a zigzag line like the boyscout), q circular movement (like the rose), and then (for pieces that start moving in one direction and then continue in another, like the gryphon). In addition, Betza has also suggested adding brackets to his notation: q<nowiki>[</nowiki>WF<nowiki>]</nowiki>q<nowiki>[</nowiki>FW<nowiki>]</nowiki> would be a circular king, which can move