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
Skewer (chess) Skewer (chess) In chess, a skewer is an attack upon two pieces in a line and is similar to a pin. A skewer is sometimes described as a "reverse pin"; the difference is that in a skewer, the more valuable piece is in front of the piece of lesser value. The opponent is compelled to move the more valuable piece to avoid its capture, thereby exposing the less valuable piece which can then be captured (see chess piece relative value). Only pieces that can move an indefinite number of squares in a horizontal, vertical, or diagonal line (i.e. bishops, rooks,