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 "pao" and "vao" (derived from the Chinese cannon) and the "mao" (derived from the horse). Those derived from the cannon are distinguished by moving as a hopper when capturing, but otherwise moving as a rider. Pieces from xiangqi are usually circular disks, labeled or engraved with a Chinese character identifying the piece. Pieces from shogi (Japanese chess) are usually wedge-shaped chips, with kanji characters identifying the piece. Fairy pieces vary in the way they move, but some may also have other special characteristics or powers. The joker (in one of its definitions) mimics the last move made by the opponent.