A humble variant
Invented by Robert Price
I got the idea for this variant while I was reading the
FIDE Handbook for
the first time. Most chess variants are made by adding some
additional rules, or modifying existing ones. This variant
results from the deletion of a rule, or at least part
To quote article 5.1.a of the FIDE Handbook effective July 1, 1997:
The italicized portion is necessary because, ordinarily, an
illegal move is allowed to stand if its illegality is not noticed
before the end of the game, so an illegal move resulting in
checkmate would otherwise not have a chance to be declared
- "The game is won by the player who has checkmated his
opponent's king. This immediately ends the game,
provided that the move producing the checkmate position
was a legal move. [Emphasis mine]"
In Cheapmate Chess, all FIDE Chess
rules apply except for that italicized section. Thus it is
possible to achieve checkmate by means of an illegal move.
I call this situation cheapmate.
Now, I don't want to allow the movement of multiple pieces, or
the reintroduction of pieces that have already been captured,
so here are the rules governing the FIDE-illegal move:
If the FIDE-illegal move results in checkmate or stalemate, then
the game is over. Otherwise, the opponent may declare that the
move was illegal, and, according to the rules of FIDE Chess,
the position is reset to just before the offending move, and the
player who made the move makes another. Attempting to play
an illegal move is not, in itself, grounds for a penalty or
loss of game.
- The active player moves exactly one of his own pieces from
any position on the board to any position that is empty or
occupied by an enemy piece other than the King.
In the latter case, the enemy piece is
captured. No other pieces are moved, captured, uncaptured or
- You may not play an illegal move that puts or leaves your
King in check.
- You may not play an illegal move if your opponent has
already done so. So, an illegal move can't be used to
escape from cheapmate.
- Note that you cannot play an illegal move to escape from
checkmate, because checkmate ends the game immediately.
There is a Zillions of Games implementation of this game
(should appear below in the "see also"),
but it runs into "Too many moves were generated" trouble when
you try to make the computer play. Also, it lets you play an
illegal move at any time, but if the enemy can evade check,
Written by Robert Price
WWW page created: May 24th, 2002.