The intent of this variant is to allow players to bribe / convert / extort opposing pieces into the player's camp. The exact method (bride, prosyletizing, comprimising photos, etc.) is left to the imagination, but such a job will require the use of a player's (limited) resources. Such maneuvering can be costly - but potent.
A player may, in lieu of his usual move, expend some resources to subvert (bribe/extort) an enemy piece from the opposing camp (color) to the player's own.
The player making the subversion must have a man (not a pawn) adjacent to the piece to be subverted. Pawns may be subverted, but may not carry out subversions.
The subverting player removes one (1) of his own pawns from the game. The piece being subverted is then swapped for one of the player's color (or is otherwise marked; see below).
Removing the pawn from the game represents the player expending resources: if you bribe an enemy bishop, you won't be able to feed and arm all your foot soldiers.
Kings may not be subverted.
No piece may be subverted while standing on a space adjacent to his king.
A piece giving mate may not be subverted.
A subverted piece may immediately give check and/or mate, if so positioned.
A player in check may only subvert an enemy piece if it gets him out of check.
A piece giving check may be subverted, but it costs more:
To subvert a checking pawn, knight or bishop requires that the subverting player remove any piece of value greater than a pawn.
To subvert a checking rook requires that the subverting player remove a rook, queen, 2 bishops, 2 knights, 1 bishop and 1 knight, or 1 knight or bishop andall remaining pawns on the board. If the subverting player has no remaining pawns, he may not use this last payoff method.
To subvert a checking queen requires that the subverting player remove any 3 pieces greater than a pawn, or any 2 pieces greater than a pawn and all remaining pawns.
If these sound like desperation moves...they are!
A subversion ends a player's turn. No pieces may move or capture on a turn during which a subversion is made.
A piece may be subverted an unlimited number of times.
I have the remnants of several cheap chess sets, so it's easy enough to lay my hands on 3 bishops, 10 pawns, etc. If you don't have as much junk as I do, you can reintroduce captured pieces, set converted pieces on checkers, coins, etc.