Chess variant

CommonerRoyal knightCommoner

Chess variant where the role of the king and knight is exchanged: players win by checkmating the knight, and the kings are regular pieces subject to capture.

Royal knight

Starts on the field of the king. It moves like a knight, but the check-rule applies to it like to a king: it cannot move into check, it has to move out from check, and if it cannot escape from check, it is an immediate loss of the game (checkmate).


They start on the fields of the knights. They move like the king, but the check-rule does not apply to them, i.e. they can be captured like any other piece.

Otherwise the rules of chess apply, with the following differences:

Examples of checkmated knight
Basic mates

The following table shows which pieces or piece combinations can checkmate the lone knight.

The queen can checkmate the knight on its own, but neither of the other pieces can (not even with the support of the knight). However, any two pieces (besides the knight) can checkmate (except the very rare case of two bishops on the same field colour).

For comparison, see: Basic endgames.

PiecesResultChance, moves (?)Notes
Royal knight Royal knightDraw  
Royal knightQueen Royal knightWin100% – 4 – 1.8 Easy checkmate, even without the support of the knight. The queen needs to force the knight step by step to the edge of the board, where it can be easily checkmated.
Royal knightRook Royal knightDraw0.57% – 1 – 1.0 Mate exists, but cannot be forced.
Royal knightCommoner Royal knightDraw1.82% – 8 – 3.4 Mate exists, but generally cannot be forced, except in special cases where the knight is already closed into the corner.
Royal knightBishop Royal knightDraw0.01% – 1 – 1.0 There is no mate (which can occur in the game).
Royal knightRookRook Royal knightWin99.99% – 8 – 4.3 Relatively easy mate (the knight is not needed). The rooks need to force the knight to the edge of the board, by standing on adjacent files.
Royal knightRookCommoner Royal knightWin99.92% – 12 – 7.3 Not too difficult mate (the knight is not needed).
Royal knightCommonerCommoner Royal knightWin99.63% – 16 – 10.4 Not too difficult mate (the knight is not needed). The final checkmate can be delivered by only one commoner, but both are needed to force the knight into the corner.
Royal knightRookBishop Royal knightWin99.85% – 12 – 6.8 Not too difficult mate.
Royal knightCommonerBishop Royal knightWin99.88% – 16 – 10.9 Not too difficult mate.
Royal knightBishopBishop Royal knightWin99.93% – 15 – 10.1 Not too difficult mate. The two bishops needs to move on different colours. The support of the knight is required.

Bruce Zimov, 1972[]

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