Help for DOUBLE CHESS

Introduction

DOUBLE CHESS was invented by David Short in 1996.

DOUBLE CHESS is a very simple chess variant which uses only orthodox chess pieces. The setup appears below. Lay two 8 by 8 boards side by side and use two chess sets. Replace the second set of kings with a third set of queens. Place the first army in the center of the board (rows e-l) and the second army out in the wings (rows a-d, m-p).

      a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 
  8 |*R*|*N*|*B*|*Q*|*R*|*N*|*B*|*Q*|*K*|*B*|*N*|*R*|*Q*|*B*|*N*|*R*|  8
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 
  7 |*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|*P*|  7
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  6 |   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|  6
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  5 |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |  5
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  4 |   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|  4
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  3 |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |:::|   |  3
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  2 | P |:P:| P |:P:| P |:P:| P |:P:| P |:P:| P |:P:| P |:P:| P |:P:|  2
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 
  1 |:R:| N |:B:| Q |:R:| N |:B:| Q |:K:| B |:N:| R |:Q:| B |:N:| R |  1
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ 
      a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p

The default (large) board display may be too wide for display in some mail reading software. It may be desirable to use the small board display in that case. The command to switch to the small board display is "doublechess set [userid] [password] small". In the diagram below, black pieces appear in CAPITAL LETTERS, white pieces in lower case.

     a b c d e f g h i j k l m n o p
   +---------------------------------+   
 8 | R N B Q R N B Q K B N R Q B N R |  8
 7 | P P P P P P P P P P P P P P P P |  7
 6 |   -   -   -   -   -   -   -   - |  6
 5 | -   -   -   -   -   -   -   -   |  5
 4 |   -   -   -   -   -   -   -   - |  4
 3 | -   -   -   -   -   -   -   -   |  3
 2 | p p p p p p p p p p p p p p p p |  2
 1 | r n b q r n b q k b n r q b n r |  1
   +---------------------------------+
     a b c d e f g h i j k l m n o p

All of the basic rules of chess, including en passant and pawn promotion. The only special rule in DOUBLE CHESS is the castling rule. The king may castle with ANY of the rooks, provided that neither piece has moved, that the king doesn't move over or onto a square controlled by an ememy piece, isn't castling while in check, and that all the squares between are vacant. Of course, each player may only castle once during the game. When inside castling, the king moves two squares. When outside castling, the king moves 4 squares. So, for White, inside kingside castling, king goes to k1 and rook goes to j1. For inside queenside castling, king goes to g1 and rook goes to h1. For outside kingside castling, king goes to m1 and rook goes to L1. For outside queenside castling, king goes to e1 and rook goes to f1. Likewise for Black instead change the "1" to "8".

The commands on the PBeM server for castling in DOUBLE CHESS are as follows:

O-O or Kk1/Kk8 is the command for inside kingside castling
O-O-O or Kg1/Kg8 is the command for inside queenside castling
O-O-O-O or Km1/Km8 is the command for outside kingside castling
O-O-O-O-O or Ke1/Ke8 is the command for outside queenside castling

All other moves are transmitted in standard shorthand english algebraic.

Some sample doublechess games can be found at http://www.chessvariants.com/large.dir/doublechess/games.html