all of the opponent's pieces or promoting a pawn). Tamerlane chess and chu shogi allow multiple royals to be created via promotion. With multiple royal pieces the game can be won by capturing one of them (absolute royalty), or capturing all of them (extinction royalty). The rules can also impose a limit to the number of royals that are allowed to be left in check. In Spartan chess, Black has two kings, and they may not both be left in check even though they can not both be captured in one turn. In Rex Multiplex, a fairy chess condition, pawns can promote to king: a move that checks multiple kings at once is illegal unless all the checks can be resolved on the next move; checkmate happens when a move checkmates all kings of the opposite colour. (A player may not expose any of their kings to check or checkmate, even if it is to resolve checks or checkmates on other attacked kings.) Pieces, when moving, can also create effects (temporary or permanent) on themselves or on other pieces. In knight relay chess, a knight grants any friendly piece it protects the ability to move like a knight. This ability is temporary and expires when the piece is no longer protected by a knight. In Andernach chess, a piece that moves or captures changes its colour; in volage, a genre of fairy chess problems, a piece changes colour the first time it moves from a light square to a dark square (vice versa), after which its colour is fixed. In Madrasi chess, two pieces of the same kind but different colour attacking each other temporarily paralyse each other: neither may move until the mutual attack is broken by an outside piece. The basilisk from Ralph Betza's Nemoroth inflicts a permanent form of this paralysis (but paralysed pieces may be pushed by the go away, another piece in the game, so they are only prevented from moving of their own accord); the ghast from the same game restricts friendly pieces within two squares of it to moves that take them geometrically further from it, and compels enemy pieces to do so (similar to the compulsion of resolving check in orthodox chess). The immobiliser from Baroque chess immobilises any piece next to it; the fire demon from tenjiku shogi and poison flame from ko shogi capture any enemy pieces that end the