Hostage chess
Hostage chess is a chess variant invented by John A. Leslie in 1997. pieces are not eliminated from the game but can reenter active play through drops, similar to shogi. Unlike shogi, the piece a player may drop is one of their own pieces previously captured by the opponent. In exchange, the player returns a previously captured enemy piece which the opponent may drop on a future turn. This is the characteristic feature of the game.
Hostage chess has tactical subtlety and "tends to favour the attacker". In 1999, David Pritchard called the game "the variant of the decade". It was published in magazines Nost-algia, Eteroscacco, and Variant Chess. It was the "Recognized Variant of the Month" in January 2005 at The [Chess Variant Pages].
Game rules
Hostage chess follows all the standard rules of chess excepting how captured men are treated. Each player owns reserved spaces off the chessboard: a prison to the player's right, and an airfield to the player's left. There should be a clear boundary between each player's prison and the other player's airfield. Captured men are not removed from the game but are held in the capturer's prison. Instead of making a normal move, a player can perform a hostage exchange to "rescue" a man held prisoner by the opponent and drop the freed man back into play on the board onto an open square. The man exchanged for the dropped man is transferred from the player's prison to the opponent's airfield. On any turn, instead of making a normal move, a player can drop a man from his airfield into active play on the board.Hostage exchanges
A hostage exchange is performed by transferring a piece from one's prison to the opponent's airfield, then selecting and releasing a piece from the opponent's prison and immediately dropping it onto an empty square on the board. The drop completes the turn. The piece transferred must be of equal or greater value than the piece released from prison and dropped. The relative piece values are: Q > R > B = N > P. A hostage exchange cannot be refused by the opponent.Drops
A drop can occur as part of a hostage exchange, or directly from a player's airfield. The square dropped to must be unoccupied. Additional drop rules:- A pawn may not be dropped on the 1st or 8th. A pawn dropped on the player's 2nd rank inherits the normal two-step move option. A dropped pawn may not be captured en passant immediately after the drop.
- A rook dropped on a rook starting square can be used in castling.
- A bishop can be dropped onto the same color square as a friendly bishop already on the board.
Pawn promotions
So, if a pawn is on its player's 7th rank with no available piece to promote to:
- The pawn cannot advance.
- If the opponent's king is diagonally in front of the pawn:
- * The pawn does not give check.
- * The opponent may not capture a Q, R, B, or N.
Advantages over Chessgi
Notation
is used with some extensions:- A drop is indicated by an asterisk. For example, N*c7 means that a knight was dropped from the player's airfield onto c7.
- For a hostage exchange, contain the man exchanged followed by the man freed from prison and dropped. For example, N*c7 means that a bishop was exchanged to free a knight, and the knight was dropped onto c7.
- Pawns are notated P in hostage exchanges, for example: *g5. The move *g5 means that a pawn was dropped from the player's airfield onto g5.
Example game
1. d4 d5 2. c4
2... dxc4
3. Nc3 e5 4. d5 c6 5. e4 b5
6. dxc6
6... *d4
7. *d7
7... Nxc6 8. Qxd4
8... Bxd7
9. Qd1
9... *d4
10. Nd5 Bb4+ 11. Bd2 Bxd2+ 12. Qxd2 Be6 13. a4
13... Bxd5 14. exd5
14... B*b4
15. *c3 dxc3 16. bxc3
16... Bxc3 17. Qxc3
17... B*b4
18. Qxb4 Nxb4
19. Rb1
19... *d2+ '''20. Kxd2
20... Qxd5+ 21. Kc1 Na2+ 22. Kc2 *b3+ 23. Kb2 B*c3+ 24. Ka3
24... b4 '''