To illustrate the above, let's look at the following position:
Black to move
1. ...c4-c3-c1=Q
The black pawn c4 made a Superpermutation, becoming the queen on square c1.
Now White checkmates in one move.
2. f4-f5-f7#
The white pawn f5 begins the Superpermutation.
First, the pawn changes places with the knight:
Changing places with the f7 pawn, the white pawn declares check and this completes the Superpermutation.
But this is not just a check, but a checkmate. The black king cannot capture Ke8xf7, since a Superpermutation will begin for him, as a result of which he will be in check:
Since the player's king must not remain under attack at the end of his turn, the move f4-f5-f7 is a checkmate for Black.
The game follows the rules of Standard Chess exactly, with the following exceptions:
- There are no capture in Superpermutation Chess. The only exception is the King. Only the King can capture the opponent's pieces.
- There is no castling and en passant in the game.
- When a player moves a piece to the target square, any piece standing in front of it on the adjacent square vertically changes places with it. This called Superpermutation. If, as a result of the Superpermutation, another piece again stands in front of such a piece, then the Superpermutation continues until there is an empty square or the edge of the board in front of the piece making the Superpermutation.
For example, if in this position
you make a knight move Nc2-e3
then the Superpermutation will begin
which will result in the following position:
exchanging places with other pieces, the knight on e3 moved to e8.
Although all other pieces are not aggressive towards each other, they can threaten the opponent's King, as in regular chess, by declaring check or checkmate to the latter.
A player must move his King away from check and must not leave it under attack at the end of his turn.
If a piece participating in the Superpermutation declares check, then the Superpermutation in this case ends and the opponent must remove his king from check.
The Superpermutation of a piece for a player is always carried out strictly upwards vertically.
As a result of the Superpermutation, the Pawn can end up on either the first or the last rank.
In the first case, the Pawn can make only one step to the second rank, from which, as in regular chess, it can move immediately two squares in its next turn.
In the second case, having reached the last rank, again as in regular chess, the Pawn is transformed at the player’s discretion into any piece of its color, except for the King and itself.
The game uses full algebraic notation, with the final square indicated in the case of a Superpermutation.
The goal of the game, as in standard chess, is to checkmate your opponent.