From Wikipedia, the free encyclopedia
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Mate in seven
by Udo Marks (Solution here.) |
Alice chess is a chess variant played using two chess boards rather than one. It's named after the main character "Alice" in Lewis Carroll's book Through the Looking-Glass. Like a number of other variants, it was invented by V.R. Parton.
Since no square can be occupied on both boards (see the rules) it is possible to play Alice Chess on one board, while placing checkers under the pieces to indicate that they are on board B. The same effect can be done on the computer screen by using upside-down pieces instead of checkers.
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| The position after 1.Nf3 e6 2.Ne5 Bc5. |
All pieces move in the same way as in standard chess, except that Alice chess is normally played without the en passant rule. At the start of the game, the pieces are set up in their normal position on one board ("board A"), with the second board ("board B") empty. Every time a move is played, the piece moved passes "through the looking glass" to the other board; if the piece started on board A it goes to board B; if it started on board B it ends up on board A. For example, after the opening moves 1.Nf3 e6 (see algebraic notation), both pieces will move to their respective distantion squares in board B. If the game were to continue 2.Ne5 Bc5, the knight will return to board A, while the bishop will be on board B.
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| The same position above after 3.Nxf7 Bg1. |
Moves, to be legal, have to be legal on the board they are played on, and the destination square on the other board must be empty. So, pieces may only capture pieces that are on the same board they are on; so pieces on board A capture other pieces on board A, and pieces on board B capture other pieces on board B. After a capture has been made, however, the capturing piece is moved to the other board, just as it would be after a non-capturing move. If the game above were to continue 3.Nxf7, the knight will transfer to board B. In this position, the black moves 3...Kxf7 and 3...Bxf2 are both illegal. Also, black cannot play 3...Qd4, because normally, it cannot hop over the pawn on d7. However, 3...Bg1 is possible, despite the fact there is a white pawn on f2 on board A: the black bishop has started out on board B, the move Bc5-g1 is legal there, and the square g1 is empty on board A. This is all that matters.
[edit] Sample games
[edit] The Fool's mate
A lot of fool's mates exist, one being: 1.e4 d5 2.Be2 dxe4 3.Bb5# (see diagram.)
At first glance it might seem that black can interpose a piece between white's bishop and his king to block the check (playing, for example, Bd7 or Nc6), but any piece so interposed immediately disappears onto the other board. Black can also not play Kd7 to move his king onto the other board, because this move is not legal on the board on which it is played (the king on d7 on the first board is still in check). Therefore, black is checkmated.
Another possible short game is 1.e4 d6 2.Bc4 Qxd2?? 3.Bb5#
[edit] The Scholar's mate
1.e4 h5 2.Be2 Rh4 3.Bxh5 Rxe4+ 4.Kf1 d5 5.Qe2 (thinking of 6.Qb5#) 5...Bh3# Superimposing the two boards shows an orthodox position where the Bh3 is attacked twice, its diagonal is blocked at g2 and the white king has a flight at e1; but the Alice interpretation is quite different.
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| The position after 11.O-O-O |
[edit] Paul Yearout v George Jelliss, AISE Grand Prix 1996
In this game, move returning back to board A are indicated by /A after the move. The annotation is by George Jelliss.
1.d3 Nf6 2.Nc3 c5 3.Qd2 Nc6 To give a direct check to the king the checking piece must come from the other board, so it is necessary first to transfer forces to the other board 4.d4/A Rb8 This way of developing Rooks is common in Alice chess 5.e3 g5 This prevents the Bc1 coming to g5 or f4 6.f4 Rbg8/A guarding Pg5 on the other board 7.Nd5/A h6 8.Nf3 gxf4/A Inconsistent play on my part. Ne4 now looks better to me 9.Bxf4 Rg4 10.Be5/A Rh5 11.O-O-O (see diagram) Perhaps judging that the activised black force now being on the second board the king might be safer there. The black queen is now effectively ‘pinned’: 11..Q-c7/b6?? 12. Qd8# 11..Ne4/A 12.Bc7 Ra4/A 13.Ba6 Bg7 The idea is 14...Rc4† 15. c3/Sc3 Bxc3+ 14.Bb5/A Rc4+ 15.Kb1/A Rf5/A 16.Ba5/A Desperate measures now needed to save the ‘pinned’ queen 16..Rxd5 17.Qxd5/A Qxa5 Threatening 18...Qa1# 18.a3 Qd2/A 19.Qxd7+ Kf8 I put these two moves in as an if...then clause, but it seems Paul may not have noticed the discovered check, so perhaps I should have kept quiet! 20.Qxg7/A Qc3 stops Qh8# 21.Rd8 Black resigns 1-0 if 21...Bd7/Be6/Nf6 22. Qg8/Re8/Qh8#
[edit] Variations
The game can be played with minor rule modification. For example, in a variant called Alice Chess 2 in [www.SchemingMind.com SchemingMind.com], White and Black start on different boards. In another variant called Ms. Alice Chess, null-moves (transferring a piece from a certain square to the corresponding square on the other board,) are allowed.
In his original article, V. R. Parton suggested a smaller version, shown on the diagram on the left. Also, it is possible to play Alice Chess in three boards, with pieces transferring from A to B, B to C, and/or C to A, or that the destination board is left to the player's choice. The Alice rules can be applied as well to any other chess variant, most notably Raumschach.
[edit] External links
[edit] Where to play
It is possible to play Alice Chess in the correspondence form in:
