An Ordinary Variant

On this page, an enlarged variant of Chess is proposed that attempts to add quite a bit to the complexity of the game for the amount that it enlarges the board.

The board is enlarged to ten ranks and twelve files.

The Rules

Each player has three rows of pieces. The third row from the back contains only four pieces, which, for want of a more appropriate name, I will simply call Checkers, although their move is not quite that of a piece in that game.

Their arrangement, as seen in the diagram, is

-- Ch -- -- Ch -- -- Ch -- -- Ch --

where an empty square, whether white or black, is represented by two dashes.

• When they are not capturing, they move like the King, one space in any diagonal or orthogonal direction. To capture, they move two spaces in those same directions, both in the same direction, jumping over an enemy piece on the intervening square, which is captured.
• As they can move and jump backwards, they do not promote.
• If one of a player's Checkers, or one of that player's Pawns, can capture a Checker without exposing its own King to check or leaving the King in check, it is compulsory to capture that Checker, although it is not necessary to do so with a Checker or a Pawn if another piece can also capture that same Checker. If multiple such captures are available, it is compulsory to capture any one of the Checkers so exposed to capture by a Checker or Pawn, but the choice of which one is at the player's discretion.
• If a player's King is in check, even when there is a capture of an opposing Checker by a Pawn or Checker available, that player's next move must be one which moves his King out of check. If one or more captures of an opposing Checker that is en prise from a Pawn or Checker, either by that Pawn or Checker or by another piece, is among the moves by which escape from check is possible, then one of those moves must be taken.
• If a player's King is not in check, but there are captures of a Checker by Pawns or Checkers available, all of which would expose that player's King to check, that player is required, if such a move is possible, to move so that this situation ceases to exist. This can be done by any means, including moving so that an alternative Pawn or Checker capture of a Checker, which does not involve moving into check, becomes available. But if such a move is not possible, that player then must make a different move. This situation does not constitute any form of mate.
• A Checker may make multiple capturing jumps in the same or different directions, as in Checkers, one after the other in a single move. It is not compelled to make a capturing move that includes capturing an enemy Checker when the first piece captured is not a Checker.
• A Checker in this game has the additional power of jumping over an allied piece without capturing it to extend its move; these jumps can also be multiple. As well, one or more consecutive non-capturing jumps over allied pieces may be followed by one or more consecutive capturing jumps over enemy pieces. This move may of course be familiar to some readers as the Knight's Charge from the commercial games Chivalry and Camelot by Parker Brothers.
• As with a capturing move that does not capture a Checker as its first step, this move is not compulsory even when it would capture a Checker.
• A series of jumps does not need to be completed, but if it is possible to jump over and capture one of the opponent's Checkers on the next step, that next jump must be included in the series if the preceding jump bringing the Checker to that position is made.

It may be noted that even with the limitations noted above, the compulsory nature of capturing a Checker provides that piece with an immense power, since it can break up Pawn formations.

The second rank from the back contains twelve Pawns. Despite the enlarged board, on their first move they only have the privilege of moving two squares forwards, subject to en passant capture, not three. In this game, a Pawn may be taken en passant by one of the opponent's Checkers as well as by one of the opponent's Pawns; the Checker would jump over the intervening square the Pawn passed through on its two-square move, to an empty space beyond, and capture the Pawn that way.

The back rank contains the array:

Rook, Knight, Bishop, Tiger, Queen, Man, Leo, King, Tiger, Bishop, Knight, Rook.

• The Man is an ordinary chess piece that moves, like the King, one space in any orthogonal or diagonal direction, but which has no special moves or powers.
• The King, when Castling either to Kingside or Queenside, moves exactly three spaces; otherwise, its move is exactly the same as in normal Chess (except for the conditions on compulsory Checker capture noted above).
• Neither of the two squares the King moves through when Castling may be under attack (even though the King does not have the option of a two-square Castling move).
• The Tiger is a piece described on earlier pages; it moves as a Bishop, but captures as a Knight. When one has Tigers of opposite colors, a capture has the cost of placing both Tigers on the same color; this long-term consequence of a capture adds another element of complexity to the game.
• And then there is the Leo, represented by a cannon symbol. It moves almost as the Cannon or Pao in Chinese Chess, or Hsiang Ch'i, but on Queen lines instead of Rook lines; thus, it is a combined Pao plus Vao, which is known in Fairy Chess as the Leo. When not capturing, it moves as the Queen; when capturing, it moves on Queen lines, passing over exactly one man of either color to capture the next piece beyond (which, of course, must belong to the opponent).

Games are scored by means of Dynamic Scoring, allowing a partial win by stalemate, bare king, or perpetual check.

Further Notes

Note that the extensions of either Spectral Realm Chess or Antimatter Universe Chess can be combined with it as they can to ordinary Chess.

In the case of the Checker, there are some important considerations which apply to its move. In the case of Spectral Realm Chess, a Checker can move a half-step diagonally to enter the alternate board, or make a jump of two diagonal half-steps to move one square diagonally on one board, capturing the intervening piece on the other board. In the case of Antimatter Universe Chess, a Checker also can move one square diagonally on one board, capturing the piece on the intervening square on the other board, but this is now a move, rather than a jump, and so multiple steps of this type in a single move are not possible.

Note also that, in Spectral Realm Chess, a series of multiple jumps must all be made in either the normal board of squares, the normal board of points, or the compound board. However, a series of jumps may mix orthogonal and diagonal jumps, and an orthogonal jump on either normal board is also a diagonal jump on the compound board, therefore, orthogonal jumps on one normal board may be mixed with either diagonal half-step jumps, which are orthogonal jumps on the compound board, or with diagonal jumps on that normal board, but not both.