Trampoline Chess

This is a rather modest variant introducing one unorthodox piece, called a Trampoline, not found in usual Chess. The rules are the same as those for usual Chess, except for the rules concerning the Trampoline.

Rules

Each player has one Trampoline, which begins off the board. A player may use his turn to drop his Trampoline onto any vacant square. This rule continues to apply after the Trampoline is on the board; i.e., a player may use his turn to move the Trampoline to any vacant square. The Trampoline cannot captureâ€”it can only be moved to a vacant square. Neither can a Trampoline be captured.

Although no piece can occupy the square where a Trampoline is located, the Trampoline does not block the sliding movement of a Bishop, Rook, or Queen. A Knight can also jump over a Trampoline, just as it can jump over any other piece. A Pawn cannot occupy the Trampoline's square but it can make its initial doublestep move through a square occupied by a Trampoline, on the third rank (for White) or the sixth rank (for Black). However, the King and Rook cannot castle through a square occupied by a Trampoline.

Although no piece can move to the square where a Trampoline is located, any friendly Bishop, Knight, Rook, Queen or Pawn (except on the Pawn's initial doublestep move) that would normally be able to move to that square may instead move immediately to any square whither it would be able to move if it were starting from the Trampoline's square. Conceptually, it can leap onto the Trampoline and immediately bounce off onto a second move. However, the move must change the board, so the piece must move to a square other than the one where it started, except as noted below. Note that a player cannot use the enemy Trampoline in this way. Also note that a King cannot use the Trampoline.

If a friendly Trampoline occupies the square on the last rank whither a Pawn could move and promote, the Pawn can promote as in usual Chess and bounce from the square as whatever piece it promotes to. In making such a move, the promoted piece may return to the Pawn's starting square: this is the only instance where a Trampoline-enabled move can so return to the original square, and it is allowed because the move changes the board (the piece returning is no longer a Pawn).

Computer Play

If you have Zillions of Games installed on your computer, you can play this game. Download file: ZRF.zip.

Equipment

The Trampoline could be represented by a checker.

Sample Game

Here is a game played by Zillions of Games against itself, set for 30 seconds of thinking and moderate variety of play.

    White   Black
 1. Nc3     e5 
 2. e4      Nc6 
 3. Tf3     Te7

Both sides drop their Trampolines early to develop their Queens and their Knights. Zillions seems to have taken care not to allow the Trampolines to interfere with normal Pawn development; White's Pawn on f2 can still move to f4 because Trampolines do not block Pawn doublesteps.

 4. d4      exd4 
 5. Nxd4

The first Trampoline-enabled move: Knight at g1 takes Pawn at d4.

 5. ...     NxN 
 6. QxN     Nc6

The second Trampoline-enabled move: Knight at g8 moves to c6, forcing the White Queen to retreat; but she retreats to a square whence she has much more power, due to her Trampoline.

 7. Qd3     Qe6

Black uses Trampoline to move his Queen out.

 8. Bf4     d6 
 9. Td5

White relocates his Trampoline for the first time, enhancing the power of his Queen and Knight. Black will reply with a Trampoline-enabled move to relocate his Bishop to the other side of his unmoved King, perhaps planning to castle.

 9. ...     Bd8 
10. Be2     Tf6

Black moves his Trampoline to attack White's Bishop...

11. Be3     Tg4

... and again, to pressure the Pawn at g2. The Trampolines are used a lot in the next several moves.

12. Nf4     Qh4
13. g3      BxBe2
14. NxBe2   Qf3

After White castles, Black's Queen uses two tempos to retreat to a square she could have reached in one: apparently some danger came into Zillion's focus after White's move 16.

15. o-o-o   Qe6
16. Qb5     Qc8
17. Te5+!

By moving the Trampoline, the White Queen gives check while still pinning the Knight that could have interposed. Black then gives up his right to castle; why didn't he interpose with his Bishop instead? Then, White makes a Trampoline-enabled pawn capture.

17. ...     Kf8
18. xd6     a6
19. Qc5     QxN

Black's Trampoline-enabled capture of the remaining White Knight tips the material balance in his favor, but his fate is already sealed.

20. xc7+    Be7
21. Td8+    Re8
22. RxR+    KxR
23. Qd5+    Bd6
24. QxB+    Qd7
25. c8=Q#

Checkmate!

It seemed to me that the Trampoline affected the game to just the extent that I had hoped: it becomes a strategic focal point but doesn't make everything else irrelevant. It may enhance the power of friendly pieces so much as to make the Queen too dominating; perhaps a variant on the variant would be to demote Her Highness back to a Ferz. Postscript: Alfred Pfeiffer points out in the comments that Joao Neto's earlier game Hop Chess is similar to Trampoline Chess. The major differences are that players can use the enemy Hopper (equivalent to the Trampoline here), and players move both a piece and their Hopper each turn. I don't remember reading about Hop Chess before now but it might have been in my subconscious when I thought of Trampoline Chess. I should also add that it was my brother, John L. Thompson, who suggested that the Trampoline should not interrupt the sliding moves of the Bishops, Rooks, and Queens, lest it turn into a defensive piece.

Written by J. Mark Thompson.

WWW page created: December 2, 2009.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Mark Thompson.
Web page created: 2009-12-06. Web page last updated: 2009-12-06

Comments

Trampoline Chess. Each player has a Trampoline that allows friendly pieces to make a second move. (8x8, Cells: 64)

Charles Gilman wrote on Wed, Dec 30, 2009 01:57 AM EST:

Good point, but don't forget the link: Taxi. Now you mention it I recall other examples of other things that contain pieces: the ships in David Jagger's PiRaTeKnIcS, the trains in Ralph Betza's PASGL 312 Chess and François Tremblay's Subway Chess, and the Trojan Horses in Gary Gifford's Shatranj of Troy. Some of these can capture in their own right, of course, but others need something 'on board' them.

Anonymous wrote on Mon, Dec 28, 2009 10:22 PM EST:

How about the 2 taxis in Taxi, the Nuclear C.a.B. Chess game? They are described as mobile board squares. They move other pieces around but are themselves just 2 squares from opposite ends of the board.

Charles Gilman wrote on Mon, Dec 28, 2009 02:11 AM EST:

You could be right, I was just lumping them together as 'not covered anywhere else'. One further connection is that Ferry moves along the River, but it could be regarded as a multi-cell non-capturer moving along a pair of ranks. They seem to me to fall into three groups.
	The Ferry, Halter, and Trampoline can all move, either under their own steam or with the aid of another piece, but cannot capture and have a different effect on pieces. They can therefore be considered special cases of non-capturing pieces.
	The Raft and Tardis are board sections that move - and again do not capture. They take their pieces with them.
	The Bridge, Fortress, and River do not change their location on the board but still affect how pieces move.

Garth Wallace wrote on Sat, Dec 26, 2009 05:53 PM EST:

Conflating nonmoving board features with noncapturing pieces doesn't make a lot of sense to me. The only overlap seems to be the Tardis, which is a bit of board topology that can be moved by the player.

Charles Gilman wrote on Sat, Dec 26, 2009 03:14 AM EST:

I've just remembered another myself, the Bridge from my own Anglis Qi. So that makes the list so far the Bridge of Anglis Qi, Ferry of Ferry Xiang Qi, Fortress/Palace of standard Xiang Qi, Halter of VeCoTha, Pole of Pole Chess, Raft of Flossschach, River of standard Xiang Qi, Tardis of Tardis Taijitu, and Trampoline of this variant. Any others that I've missed?

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