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
Fork (chess) Fork (chess) In chess, a fork is a tactic whereby a single piece makes two or more direct attacks simultaneously. Most commonly two pieces are threatened, which is also sometimes called a "". The attacker usually aims to gain by one of the opponent's pieces. The defender often finds it difficult to counter two or more threats in a single move. The attacking piece is called the "forking" piece; the pieces attacked are said to be "forked". A piece that is defended can still be said to be forked if the forking piece has a lower value. Besides attacking pieces,