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
Empress (chess) attacking archbishop two squares diagonally away), while the rook+knight compound cannot. Worse, the word empress suggests a piece stronger than the queen, while this piece is at best equal to and perhaps weaker than the queen, especially in the endgame. The empress was first used in Turkish Great Chess, a large medieval variant of chess, where it was called the "war machine" (dabbabah; not to be confused with the piece more commonly referred to as the dabbaba today, which is the (2,0) leaper). It was introduced in the West with Carrera's chess from 1617, where it was called a "champion",