Perfect 12

Jean-Louis Cazaux (April 1999, revised June 2000)

For the Ancients 12 was a perfect number. Much more than 10, since it can be divided by 2, 3 and 4.

This game is simply a chess variant on a 12 x 12 board with 12 different pieces. The balance doesn't stop here, just consider this:

• there is the same number (18) of Pawns than other pieces
• there are as many types of riders (Queen, Rook, Bishop, Gryphon) than leapers (Knight, Camel, Elephant, Lion)
• the piece density is 0.5 exactly as for Orthodox Chess.

Among the 12 kinds of pieces, 6 are the orthodoxe ones. The remaining 6 are like a best of very famous historic and asian variants: Camel is from Tamerlane's Chess , Gryphon is from Grande Acedrex, Prince is from Courier and other medieval Chess, Cannon is from Xiang-Qi, Lion is inspired by Chu Shogi and Elephant is a slight modernization of the piece found in Shatranj.

Players

Two.

Initial Setup

The board is a 12 x 12 checkered squares with a white one at the right end of each player. For convenience, it can be divided into 16 sub-square showing halves and quarters of this large battlefield: 12 is really a nice number for a board.

There are 36 pieces per side: 1 King, 1 Queen, 1 Gryphon, 1 Lion, 2 Princes, 2 Bishops, 2 Knights, 2 Rooks, 2 Elephants, 2 Cannons, 2 Camels and 18 Pawns.

The white King is placed on the center of the second row on a black square, the black King beeing on a white square. The Queen is placed beside of the King. The Lion and the Gryphon are on the center of the first row, the Lion just behind the King.

Moves And Captures

King, Queen, Bishop, Knight and Rook are orthodox.

• Pawn: the Pawn is almost similar to FIDE Chess. There are two differences:
  It can advance one or two square from ANY position on the board. However, its capturing move is unchanged: one square diagonally forward. As a consequence, the en-passant capture is possible every time the opposite Pawn has advanced two squares.
  When the Pawn reaches the last row it can promote to one of the three major pieces: Queen, Lion or Gryphon.

• Lion: the Lion is inspired from Chu Shogi, the most popular variant of the Japanese Chess. This game is also played on a 12 x 12 board and was mentioned as long ago as the twelfth century and therefore predates modern Shogi by centuries. This Lion can move to any of the 8 squares immediately adjacent (like a King) or jump to any of the 16 squares two steps away. (Then this Lion has the same range but is more restricted than the Lion in Chu Shogi which can move 2 times in a turn).

• Gryphon: this piece comes from the Grande Acedrex, which is described in one of the very first game books in Western Europe appeared in 1283, under `editorship' of the Spanish King Alphonso X. This Libro del Acedrex contains many rules of old games. The Gryphon moves one square diagonal, followed by an arbitrary number of squares horizontal or vertical. It is authorized to go only one square diagonal. It may not jump over other pieces, and the unobstructed path must start with the diagonal movement.

• Camel: a well known piece since medieval muslim great chess like Tamerlane's Chess. It jumps to the opposite case of a 2x4 rectangle, like an extended Knight. No matter what intermediate cases contain. Note that it always stays on the same color of square.

• Cannon: borrowed from Xiang-Qi, the Chinese Chess. It moves like a Rook and needs an intermediate piece between itself and its victim to capture it. The Cannon jumps the intermediate and takes the victim on its square. The intermediate is left unaffected.

• Elephant: it is a modern extension of the Elephant found in Shatranj. It moves 1 or 2 cases diagonally. It can jump over the first case if it is occupied. This form is also used in other games from the same author like Shako and Tamerlane II.

• Prince: this piece is simply a non-royal King. It can be found in medieval games like the Courier chess , an old chess variant, played in Germany, where it is called "Man". It moves one square in an arbitrary direction, like the king, but without being hindered by check.

Castling: the King may `castle` with the Rook if neither the Rook nor King has moved yet and there is nothing in between them. In castling the King slides 3 squares to the Rook and the Rook leaps to the far side of the King. You may not castle out of or through check, or if the King or Rook involved has previously moved.

End Of Game

Victory is obtained when the opposite King is checkmated.

All other types of endgame (pat, perpetual check,...) are classic.

Pieces Value

Zillions gives these average values, normalized to 5 for the the Rook:

Pawn: 0.8, Camel: 2.2, Knight: 2.5, Elephant: 2.5,
Prince: 2.8, Bishop: 3.4, Cannon: 4.9, Rook: 5,
Lion: 7.3, Gryphon: 7.8, Queen: 8.3.

Remarks

The reader would certainly think that I am not modest, but I love this game. I like it because it is really large, balanced, and because each one of the new pieces have they own "character".

I had it in my mind for several months, I should say years ! The key to set it up definitely has been the wonderful Zillions-of-games program. Without such a tool, it would have been impossible for me to try all the so many configurations I have tested.

I came to this final implementation at the end of April 99. It was not too late to submit it to the Large Chess Variant Contest organized by David Howe yet. However, I didn't do it since I had engaged Shako and Tamerlane II already.

Perfect 12 belongs to a series:
10 x 10 board: Shako
11 x 11 board: Tamerlane II
12 x 12 board: Perfect 12
14 x 14 board: Gigachess

My dream would be to find a game editor willing to commercialize such a material for Perfect 12. With such a big board and 72 pieces, many other chess variants could be played.

The zrf for Perfect 12 is available from here.

Any Comments?

Mail me at: (email removed contact us for address) ssvarinats.com

Written by Jean-Louis Cazaux.

WWW page created: June 2, 1999. Last modified: April 03, 2001. Thanks to Ivan A Derzhanski for corrections.