Chessence
Chessence is a chess variant invented by Jim Winslow in 1989. The board is a 6×9 rectangle of squares with eight squares missing (blackened out in the diagram). Each player has a king and nine men with initial setup as shown, including three men initially not yet in play at the side of the board. To win, a player must checkmate or stalemate the opponent. Game rules
In Chessence, kings do not move and must remain fixed on their starting squares the entire game. (Thus, a king is unable to move out of check.) A man has capability to move based on its relative position to other friendly men on the board, as follows:
 If a man is  adjacent to a friendly man, then both have the ability to move as a rook in chess. If a man is  adjacent to a friendly man, then both have the ability to move as a chess bishop. If a man is a  away from a friendly man, then both have the ability to move as a knight. A man with more than one position relationship has the ability to move in more than one way. Likewise, if a man has  position relationship defined above, that man cannot move. The king has no bearing on how the other men may move. A man may not move to, nor through, a non-existent (blackened-out) square; except that a man moving as a knight may  a non-existent square. For a turn, a player may move a man on the board, or alternatively, they may put one of their reserve men in play by placing it on any of their six initial starting squares that are currently open. Checks, checkmate, and captures are as in standard chess. If a player has no legal moves, they lose the game. See also
 Beirut Chess – another chess variant by Jim Winslow

References

Bibliography

External links
 Chessence by Peter Aronson, The Chess Variant Pages
 Chessence a simple program by Ed Friedlander (Java)

Chess variants
1989 in chess
Board games introduced in 1989