Nightrider (chess) Nightrider (chess) A nightrider (also known as a knightmare or unicorn, though the latter sometimes also means the bishop+nightrider compound) is a fairy chess piece that can move any number of steps as a knight in the same direction. The nightrider is often represented by a symbol similar to the knight's icon, but altered in a way to indicate the additional straight-line motion. In this article the nightrider is represented with an inverted knight, and notation N (in which case the "knight" is abbreviated as S for German "Springer"). The nightrider was invented by T. R. Dawson in 1925, and
Fairy chess piece David Parlett used a notation to describe fairy piece movements. The move is specified in the form m={"expression"}, where "m" stands for "move", and the "expression" is composed from the following elements: The following can be added to Parlett's to make it more complete: The format (not including grouping) is: <conditions> <move type> <distance> <direction> <other> On this basis, the traditional chess moves (excluding castling and "en passant" capture) are: Ralph Betza created a classification scheme for fairy chess pieces (including standard chess pieces) in terms of the moves of basic pieces with modifiers. Capital letters stand for basic leap