The Chess Variant Pages




DoubleEIGHTEEN-STONEchess

               a b c d e f g h i j k l m n o p
             +---------------------------------+
           9 | R N B Q R N B Q K B N R Q B N R |  9
           8 | P P P P P P P P P P P P P P P P |  8
           7 |   -   -   -   -   -   -   -   - |  7
           6 | O   -   - O -   -   O   -   - O |  6
           5 | O - O O   O   O O - O - O O   O |  5
           4 | O   -   - O -   -   O   -   - O |  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

Description: This game combines the rules of EIGHT-STONE CHESS and DOUBLECHESS. Please note that there have been some discrepency in the rules of "Amoeba", an experimental game being played on the PBM server, and the intended rules of the creator of ESC. In Amoeba, one can use the piece-swap rule to swap the places of stones and opponent's pieces, as well as swap pieces of either color with a stone at the end of a line of 2 or more stones, just as one would in the extended stone swap move, instead of just swapping with a stone 1 square away from it horizontally or vertically. My new variant here would only support the traditional stone swapping rule.

For example, in AMOEBA, the following moves would be legal:

    +---------------+
    |- - O O O O - -|   Stone on C can be moved to G,
    +---------------+   Stone on F can be moved to B.
     a b c d e f g h    This complies with standard ESC rules.

But, now:

    +---------------+
    |- n O O O O - -|   Knight on B can move to G
    +---------------+
     a b c d e f g h

Also, some of extrapolated their own interpretation of the stone rules, thus that in the first diagram, the stone on D or E could also move to G, or the stones on D or E could also move to B, and likewise in the second diagram, the knight could swap places with the stones on D, E or F (as well as C) too.

My interpretation of the stone rules are very precise. In a line of 3 or more stones, only the stones on the extreme ends of the line may move down to the other extreme end of the line, for example, C to G or F to B in the first diagram, and one's own pieces and not one's opponents pieces may be swapped with stones, and then only with stones that are one square away from it horizonatally or vertically. Also, a piece may not swap with a stone if it would cause the stone to revert back to the square it was just on before the opponent's previous move. In other words, the "no undo" rule takes precedence.


Written by David Short.
WWW page created: April 23, 2000.