Chess with different armies

Chess with different armies (or Betza's Chess or Equal Armies) is a chess variant invented by Ralph Betza in 1979. Two sides use different sets of fairy pieces. There are several armies of equal strength to choose from, including the standard FIDE army. In all armies, kings and pawns are the same as in FIDE chess, but the four other pieces are different.

Rules and armies

Before the game players choose their armies in a certain way, predefined by tournament rules. This can be done either randomly or secretly by both players. Each player has a choice of 4 armies: the ''Fabulous FIDEs'', which are the standard chess pieces, the ''Colorbound Clobberers'', the ''Nutty Knights'', and the ''Remarkable Rookies''.

All armies are designed to be equal in strength but have significantly different properties. Kings and pawns move the same as in chess for all armies. Pawns can only promote to pieces of either army on the board at the start. Castling is done as in standard chess with the exception of the case when the rook replacement is colorbound, like in the ''Colorbound Clobberers'' army. In the latter case, the king, when castling long, moves to b1, and the rook replacement to c1. This is so that colorbound pieces do not change square color.

Many pieces in the following armies are combinations of standard chess pieces and 4 fairy pieces: '' ferz'', '' alfil'', '' wazir'' and '' dabbaba'' (see their movement diagrams above). The game can be played with standard chess pieces, and the following move diagrams use standard pieces as well (except queens).

Colorbound Clobberers

In this army, rooks, knights, bishops, and queen are replaced by the following pieces:

As mentioned, when using this army and castling queenside, the king moves ''three'' squares (from e1 to b1) and the bede moves from a1 to c1.

A weakness of the Colorbound Clobberers are the unprotected pawns at a2 and h2. To cure this weakness, the positions of the waffle and the FAD can be switched. This ''alternate setup'' was already proposed by Ralph Betza and is named ''Colorbound Clobberers II''.

Nutty Knights

This army includes a lot of leapers, but most of them have asymmetrical move patterns, with backward moves being restricted.

Remarkable Rookies

The rooks, knights, bishops, and queen are replaced by the following pieces:

Strength of the armies

The armies were playtested in human play among chess masters and considered balanced at the time of their release. They were not playtested in computer games because at this time no engines playing chess variants were available. The release of Zillions of Games did not change the original assessment.
In 2010, H.G. Muller tested the Colourbound Clobberers and the Nutty Knights in the stronger engine Fairy-Max and found that both armies were significantly stronger than the FIDE pieces. He found that the Nutty Knights had an advantage of slightly more than a pawn above the FIDEs, and the Clobberers slightly less than a pawn. He also notes that the advantage of the Clobberers as an army is smaller than expected from the piece values alone.

In 2015 Fairy-Max was extended to handle limited sliders such as the Short Rook from the Remarkable Rookies. H.G. Muller ran a test of all four official armies against each other with the following result:

It seems that the Rookies are the strongest of all, in agreement with ChessV and Zillions tests. By this finding, they are only marginally stronger than the Nutters, while the Clobberers seem to be about half-way in strength between them and FIDE. Statistical error in 400 games is 2%, so that means that the 3% of the Rookies-Nutters result can make us decide with >90% confidence that the Rookies indeed have the better chances here.

Proposed adjustments to the official armies

In the light of the newer strength evaluations, several weakenings of the official armies were proposed. In 2012 J. Knappen proposed an adjustment to the Nutty Knights named Drunken Nights. Here the Charging Knight is weakened by removing the step directly backwards, decreasing its endgame value. The resulting piece is called Drunken Night.

In 2015 J. Knappen discussed some weakenings of the Remarkable Rookies and the Colorbound Clobberers, including the weakening of the Bede to a piece named Busy Beaver. In this piece the Dabbaba jump is replaced by a zigzag sliding move to the same square. In 2016, Double sharp and H.G. Muller came up with playtested proposals for the Clobberers and the Rookies. In the Clobberers, the FAD is replaced by the Prime Minister that can step in any diagonal direction once or twice in one turn. It can step in another direction after its first step. It need not take both steps. It must stop when it captures. It can return to its starting square, allowing the player to skip a turn. In the Rookies, the Short Rook is even shorter and has now only two steps in each orthogonal direction. The final adjustment from a three-step short rook to two-step short rook was made in 2020.

Unofficial armies

The four armies described above were playtested by Ralph Betza and selected as the most balanced ones. There are other armies, invented by Betza and other people, some of which are presented here.

In the initial version of the game, there were 8 armies and, in these armies, the king moved differently from the king in the standard chess. Instead of normal pawns, fairy pawns could be selected – for example, Berolina pawns. However, later Betza abandoned the idea of using fairy pieces for king and pawns and reduced the number of armies to four.

Forward FIDEs (Ralph Betza)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Meticulous Mashers (Ralph Betza)

The rooks, knights, bishops, and queen are replaced by the following pieces:

All-Around Allstars (Ralph Betza)

This army is made of one piece from each of the main armies. Out of the 12 eligible combinations, as the FAD from the Colorbound Clobberers is considered too strong for a Bishop equivalent and the Cardinal from the same army too weak for a Queen equivalent, Ralph Betza considers the following to be the "official" all-star team. The rooks, knights, and queen are replaced by the following pieces:

There is another All-Around Allstars army by Ralph Betza. In this setup the restriction that an eligible piece must play in one of the four official armies is lifted and the Forward FIDEs and the Meticulous Mashers are also included. It has the following setup:

Amazon Army (Ralph Betza)

In this army, the rooks and queen are replaced by the following pieces:

Cylindrical Cinders (Ralph Betza)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Fighting Fizzies (Peter Aronson)

In this army, the left rook, the right rook, knights, bishops, and queen are replaced by the following pieces:

Avian Airforce (Ralph Betza)

In this army, the rooks, knights, bishops, and queen are replaced by the following pieces:

Spacious Cannoneers (Ralph Betza)

In this army, the rooks, knights, bishops, and queen are replaced by the following pieces:

Spacious pieces must stop one square before any piece on the board. They can advance to the edge of the board when the wraparound square is empty, a spacious rook can move from e1 to e8 because at the end of the move the square e1 is empty. Spacious pieces can capture another piece when the square behind that piece is empty, or, when the piece to capture is placed on the edge of the board, the wraparound square is empty. Spacious pieces cannot wraparound the edges of the board, the wraparound squares are only examined in the case of a move towards the border. In the Spacious Cannoneers army, several pieces combine a spacious piece with some kind of cannon piece.

Pizza Kings (John Lawson)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Seeping Switchers (Jörg Knappen)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Daring Dragons (H. G. Muller)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Bent Bozos (H. G. Muller)

The left and right rooks, left and right knights, left and right bishops, and queen are replaced by the following pieces:

Fearful Fairies (Jörg Knappen)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Silly Sliders (H. G. Muller)

The rooks, knights, bishops, and queen are replaced by the following pieces:

Hoppel-Poppel

''Hoppel-Poppel'' is originally a popular chess variant from Germany played with equal armies. Its army fits perfectly into Chess with Different Armies and is therefore listed here. In this army the knights and bishops are replaced by the following pieces:

References

{{Chess variants

Chess variants