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
Exchange (chess) piece(s) may decide whether it is worthwhile for him to initiate a capture likely to result in recapture, likely decided by the value of the pieces to be taken in the ensuing exchange. Pinned pieces often cannot be counted on being attackers or defenders. In chess, a sacrifice is the deliberate giving up of a piece by a player, allowing or forcing an opponent to capture the piece or exchange it for a lower value piece. In a desperado situation, a trapped piece which would inevitably be lost can sometimes be exchanged for another piece, even if it has lower