The Official Rules of LOCKING CHESS

BEFORE YOU BEGIN

If you’ve never played chess, first learn its basic rules. Once you know the basics, you’re ready to play LOCKING CHESS!

White always starts the game.

GOAL

Checkmate or LOCKMATE the opposing King.

PIECES

08 Pawns, 02 Bishops, 02 Knights, 02 Rooks, 01 Queen and 01 King for each player.

It is recommended to use cubic chess pieces, similar to the Bauhaus model, to make it easier to move and quickly balance them on top of each other. Staunton and classic model pieces can be adapted to allow for this dynamic overlap.

SUPERIMPOSITION RULES

1. In LOCKING CHESS, pieces on the board level can superimpose (rise and settle) on their own pieces according to their capturing move. A piece on the board level, in all phases of the game, can only superimpose on pieces of its color. Once superimposed, the pieces can move normally over the others that are on the board level, whether of their color or the opponent’s.

2. THE PAWN SUPERIMPOSITION:

The pawn is the only piece whose diagonal capture move is different from its advance move. Thus, the white pawn on its initial square a2, for example, can superimpose any piece of its color that is on squares a3, a4 or b3 in its first move.

A white pawn superimposed on d4, for example, can advance and go down to the empty c5, d5 or e5 square, or advance and superimpose any piece, whether of its color or the opponent’s, that is on the board level in one of those same squares.

This white pawn superimposed on another piece of its color on d4, as an example, can capture the opponent’s piece that is also superimposed on c5 or e5 (see CAPTURE RULES).

3. A piece on top of another piece is a SUPERIMPOSED piece. A piece superimposing another piece of its color is considered an EQUAL superimposition. If superimposed on an opposing piece, it is an OPPOSITE superimposition. A piece underneath another piece is a LOCKED piece.

4. Maximum of one superimposition per piece/square on chessboard level.

5. A SUPERIMPOSED piece, according to its movement, can move one or more squares over its own pieces and those of the opponent that are on the level of the board. And you can step down from them at any time to get back to the board level. When you land on a piece of yours or an opponent’s piece on the board level, it will “lock” it there, thus preventing its movement, but not its capture (see CAPTURE RULES).

6. SUPERIMPOSED pieces CANNOT jump over (with the exception of Knights) nor land on another already superimposed piece (see Rule 4).

7. When a SUPERIMPOSED piece moves, either down and back to the board level or superimposing another piece, the piece that was underneath it will become “free”. And the pieces on the board level that become “free” can move, capture, or superimpose and be captured or superimposed/locked again.

8. Any SUPERIMPOSED piece, including the King, can land on and “lock” the opposing King if it is on board level.

Pieces at board level and superimposing can also lock their own King that is at board level by superimposing it, thus leaving it equally vulnerable to check.

9. The King at the board level CANNOT move up and superimpose a friendly piece on the square next to the opposing King’s superimposed, but it can move to the square next to the opponent’s superimposed King and give it check if the piece under the opponent’s King is of EQUAL superimposition. And a superimposed King also CANNOT move to a piece next to the opposing superimposed King, nor move down to a square next to the other King on the board level (see LOCKMATE RULES).

10. PROMOTION: when a pawn reaches its opponent’s first rank, even if it superimposes one of its own or the opponent’s pieces on that square, it is immediately promoted to Queen, or Rook, or Knight, or Bishop, according to the chess player’s decision.

If you choose to promote the superimposing pawn to Queen or underpromote it to Rook, Knight or Bishop, and there is a friendly or opposing piece below it on its rank and promotion square, INCLUDING ONE OF THE KINGS, this piece will be “locked”.

And if a pawn at the board level captures an opposing piece “locked” in an OPPOSITE superimposition on its promotion rank, it will be immediately promoted and that newly promoted piece will be locked in place of the piece it captured.

CAPTURE RULES

1. Pieces on the board level can capture both the opponent’s pieces that are on that level and the opponent’s two pieces in EQUAL superimposition!

2. Only a free pawn on the board level (that is, with no piece superimposing it) can capture en passant.

3. A piece on the board level is allowed to capture the opponent’s pieces that are locked under a piece in OPPOSITE superimposition. Consequently, that capturing piece will take the place of the captured piece and will be “locked” under its own piece in an EQUAL superimposition.

4. The Knight is the only piece that, being at the level of the board, can capture the piece in OPPOSITE superimposition of the opponent that is on top. And if they are pieces on an EQUAL superimposition, then both will be captured by the Knight.

5. The Knight is also the only piece that, being superimposed on a piece of its color, can capture the opponent’s piece that is free on the board level.

6. The OPPOSITE superimposition piece on top can only be captured by other superimposed pieces or by a Knight on the board level. By capturing the piece on top and taking its place, the piece below will remain “locked”.

7. When a SUPERIMPOSED piece captures the opponent’s two pieces in EQUAL superimposition, it will occupy its square, thus returning to the level of the board. A piece on the board level can also simultaneously capture both opponent’s pieces in EQUAL superimposition.

8. A piece, whether at board level or superimposing, CANNOT superimpose its King if there is a superimposing piece of the opponent capable of capturing them in that EQUAL superimposition.

SPECIAL MOVES

EN PASSANT SUPERIMPOSE (eps): this LOCKING CHESS law allows a pawn superimposition exception. In the pawn’s initial two-square advance, if there is an opponent’s pawn superimposed on the adjacent file and on the same rank, it can superimpose the moved pawn and “lock” it back in the square it jumped.

…a4  b4-a3 esp

As with the en passant capture, the EN PASSANT Superimpose must be done immediately after the pawn has advanced two squares. If the player decides not to do it, he will lose the right to do so later. Like any other move, if the EN PASSANT Superimpose is the only valid move remaining, it must be made. This extra special rule in LOCKING CHESS prevents a pawn from using the initial two-square advance to pass alongside an opponent’s superimposing pawn without being superimposed and locked.

CASTLOCK: in addition to traditional castling, in LOCKING CHESS there is the alternative of CASTLOCK, a new special double move with the King and one of the Rooks.

The move consists of moving the King on the first rank sideways by two squares towards the Rook with which you want to castle, and the chosen Rook superimposes the King after the “jump”. The objectives are to protect the King, taking it off center, improve position and/or check if the opposing King is superimposed or locked in an EQUAL superimposition on the same Rook file.

As in traditional castling, there are two types of CASTLOCK: Long CASTLOCK (when performed with the furthest Rook from the Queenside) and Short CASTLOCK (when performed with the closest Rook from the Kingside).

The other conditions to allow CASTLOCK are the same as for traditional castling, with the addition that the Rook, when superimposing the King (EQUAL superimposition), DOES NOT remain in the crosshairs of the attack of a superimposed opposing piece (see CAPTURE RULES).

Short CASTLOCK, represented in notation systems as O-O

Long CASTLOCK, represented in notation systems as O-O-O

CHECKMATES RULES

1. When a “free” King — that is, at the level of the board and without superimposing — is in check and there is no way for it to escape to another square, capture, lock or block the attacking piece, will be normal checkmate.

2. A King “locked” at the board level, under a piece of its color (EQUAL superimposition), is subject to check. And if it is attacked and there is no way to lock, capture or block the check, it will be LOCKMATE, that is, a checkmate with the King immobilized!

3. A King “locked” at the board level, with any enemy piece (including the opponent’s King) superimposed on it, will also be vulnerable to LOCKMATE!

Bc3# — Example of a LOCKMATE! Bishop superimposes its own pawn on c3 to attack the black King locked in an Equal superimposition on g7.

Bc3# — Another example of a LOCKMATE!

Bishop attacks King locked in an Opposed superimposition.

4. If a “refugee” King on top of a piece of its own color (EQUAL superimposition) is in check by an opponent’s piece at the level of the board, and there is no way to go down, escape, capture, block or lock the attack, it will be a REFUGEE MATE.

5. If a “refugee” King in an OPPOSED superimposition is in check by a superimposing opponent’s piece or an opponent’s Knight at the level of the board, and there is no way to get down, escape, capture, block or lock the next attack, it will also be a REFUGEE MATE.

Bc3# — REFUGEE CHECKMATE!

6. A “free” King at board level can move into the square next to a superimposed opponent’s King in EQUAL superimposition and give it a point-blank check directly! And if there is no way for this “refugee” King to come down, escape or lock this check, it will be the ROYAL MATE!

7. A “free” King at the level of the board or superimposed on another piece can move or go down to the square next to the opponent’s locked King and give check to it only if the opponent’s piece that is eventually superimposing and locking its own King is not able to lock it by superimposing it. If there is no way to save the “locked” King from this point-blank check by a King at the board level, then it will be the ROYAL LOCKMATE!

LOCKOUT AND DEADLOCK DRAW RULES

1. A “locked” King with any other opponent’s piece superimposed on it, without being in check and without other valid moves, will be paralyzed and therefore drowned. This situation is called LOCKOUT and will be a draw.

2. If the only move of a “refugee” King that is not in check leaves it vulnerable to checkmate, it will be in DEADLOCK, that is, drowned, and it will also be a draw.

In addition, the other traditional draw rules (repetition of position, lack of material and 50 moves rule) also apply.