An amazon (also known as a queen–knight compound) is a fairy chess piece that can move like a queen or a knight (or, equivalently, like a rook, bishop, or knight). It may thus be considered the sum of all orthodox chess pieces (not including pawns). It cannot jump over other pieces when moving as a queen, but may do so when moving as a knight. Below, it is given the symbol RNB from Betza notation.
The amazon is one of the most simply described fairy chess pieces and as such has a long history and has gone by many names.[note 1] It was experimented with and used widely in the Middle Ages to replace the old slow ferz, and competed with the orthodox queen for this role; however, the normal queen eventually won out, because of the excessive power of an amazon.
The amazon appears most famously as the maharajah in the chess variant Maharajah and the Sepoys, where it is White's royal piece and also his only piece. The result of this game is a Black win with perfect play; the complete set of orthodox chessmen can force checkmate on a lone amazon.
The amazon has a very high value (estimated to be about 11⁄4 times that of the ordinary queen, that is, about 11 or 12 points) because it controls every square in a 5 × 5 square of squares centered around itself and therefore attacks everything nearby, filling a whole area with attacks once it moves into position and forces checkmate by itself. In contrast, although the gryphon from Grande Acedrex (which moves one step diagonally before continuing outwards as a rook) would seem to have the value of two rooks (about 10 or 11 points), the squares it attacks are more dispersed and it can be more easily defended against than the amazon.
In the endgame of king and amazon versus king and chancellor (rook–knight compound), the weaker side may force a draw by setting up a fortress. These fortresses force the side with the amazon to give perpetual check, as otherwise the side with the chancellor can force a simplification or give its own perpetual check. King and amazon versus king is a forced win for the side with the amazon; checkmate can be forced within four moves. In comparison, the queen requires 10 moves and the rook requires 16. In fact, the amazon does not even require its king's help to force checkmate (as an example of a checkmate position, the king is in the corner and the attacking amazon is a knight's move away from it), and this great power is the reason why it is not seen as often in chess variants as the archbishop or chancellor.
See also 
- Other names the piece has acquired include angel, ayanu, commander, crown prince, elephant, empress, general, giraffe, grand chancellor, maharajah, rettah, royal guard, superqueen, tetra queen, and wyvern.
- Piececlopedia: Amazon at The Chess Variant Pages
- Endgame statistics with fantasy pieces at The Chess Variant Pages
- Amazon Chess at The Chess Variant Pages
- Factors that Contribute to Piece Values by Ralph Betza