| a | b | c | d | e | f | g | h | i | j | |||
| 8 |  |  |  |  |  |  |  |  |  |  | 8 | |
| 7 |  |  | | | | | | | | | 7 | |
| 6 |  |  | | | | | | | | | 6 | |
| 5 | | | | | | | | | | | 5 | |
| 4 | | | | | | | | | | | 4 | |
| 3 | | | | | | | | | | | 3 | |
| 2 |  |  | | | | | | | | | 2 | |
| 1 |  |  |  |  |  |  |  |  |  |  | 1 | |
| a | b | c | d | e | f | g | h | i | j |
Janus Chess is achess variant invented in 1978 by Werner Schöndorf[1] fromBildstock, Germany. It is played on a 10×8 board and features afairy chess piece, thejanus, with the combined moves of abishop and aknight. The janus piece is named after the Roman godJanus because this god was usually depicted with two faces looking in opposite directions.
The usual set ofchess pieces is extended with twopawns and two januses per player. Each janus is placed between arook and a knight. The relative position of theking andqueen is reversed compared tochess. Aftercastling, the king stands on either the b- or i-file and a rook stands on either the c- or h-file, depending on which side castling is done.
The janus is considered almost as powerful as a queen and is usually valued at about 8 points (based onchess piece values with pawns valued at 1). It is the only piece in the game that is able tocheckmate the opponent's king without the assistance of any other piece, with the king in a corner and the janus two squares away on a diagonal, but this checkmate cannot beforced. Due to the extra pieces, each player starts the game with considerably more "material power" compared to standard chess; however, the game has only a slightly higher material "power density",[2] since there is more room for players to maneuver pieces because of the larger board (10×8 = 80 squares). Due to the different board and pieces, players are unable to use normal chessopening theory, and chesstablebases have limited value in theendgame.
Janus Chess has been popular in Europe[3] with regular tournaments drawing strong players.[1] Several chessgrandmasters have played this game includingViktor Korchnoi,Péter Lékó andArtur Yusupov. Korchnoi said: "I like playing Janus Chess because one can show more creativity than in normal chess."[1]
Chess engines that play Janus Chess: