Chessence is a Chess variant designed by Jim Winslow in 1989. It is played on a board of nine by six squares, with eight squares removed. Each player starts with nine undifferentiated pieces -- six on the board, and three in hand as reinforcements -- and an immobile King. Pieces' movement depends on their spatial relationship to other friendly pieces. The object of the game is to either to checkmate your opponent's King, or to leave your opponent with no legal moves (stalemate). It is not related to the game by Stephen Sniderman that is also called Chessence
Chessence is played on a board of nine by six squares, with eight squares removed. The removed squares may not be landed on or passed over; but they may be leapt over by a piece when moving as a Knight. The initial setup is:
The rules of Chessence follow those of orthodox chess, except when noted below. Kings are immobile, so there is no castling.
As noted above, Kings may not move. The movement of the undifferentiated pieces -- called Pawns in this document -- depends on their spatial relationship with other friendly Pawns (but not with Kings or with enemy Pawns).
If a Pawn is orthogonally adjacent to a friendly Pawn, then it may move like a Rook:
If a Pawn is diagonally adjacent to a friendly Pawn, then it may move like a Bishop:
If a Pawn is a Knight's move away from a friendly Pawn, then it may move like a Knight:
A Pawn that satisfies multiple of the above conditions may move in any of the ways it is allowed. For example:
Instead of moving a Pawn on the board, a player who still has any Pawns in hand may instead place one on any unoccupied square where one of their Pawns started the game. This counts as a move.
While checkmates can happen, and threats to mate are important, most games seem to end as stalemates when one player is left with no movable Pawns.
Ed Friedlander has also implemented this game as an applet.
This information is based on the description in Pritchard's Encyclopedia of Chess Variants.
There is an implementation of Chessence for Zillions of games. You can download it here: