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
Rules of chess procedure for determining who plays White. Instead, this decision is left open to tournament-specific rules (e.g. a Swiss system tournament or Round-robin tournament) or, in the case of non-competitive play, mutual agreement, in which case some kind of random choice is often employed. A common method is for one player to conceal a piece (usually a pawn) of each color in either hand; the other player chooses a hand to open, and receives the color of the piece that is revealed. Each type of chess piece has its own method of movement. A piece moves to a vacant square except