SLIDE-CHESS

1. Each player must on each move do one of:-
 (a) make a regular Chess move; (which includes moving or capturing into or out of either cage).
 (b) move his cage (with any contents) to any empty edge or corner square;
 (c) insert his cage (with any contents) orthogonally into the board, shifting the other cells in line until a cage appears at the opposite edge (which must have been empty).
2.  A player wins by capturing the opponent King
3. No double initial pawn step; no castling.
4. When a pawn reaches the 2nd/7th rank, its mover decides how it promotes.
5. A player may not move his cage twice consecutively.
6. No king must ever be in a cage.

Initial Setup

1         [ ]         1  [] White cage
2    r n b k b n r    2  () Black Cage
3    p p p p p p p    3
4    . . . . . . .    4
5    . . . . . . .    5
6    O O O O O O O    6
7    R N B K B N R    7
8         ( )         8
   a b c d e f g h i

Game Sample (‘>’ means a cage slide):

 1. e5 g4
 2. e1a8 e4
 3. Na8 e8a2
 4. a8d1 Ra2
 5. N:f2 K:f2
 6. d1>d8 a2>i2
 7. d6 d:e5
 8. d:e5 Bc4
 9. b:c4 N:c4
10. b5 Ne3
11. Rd7 i2d1
12. R:d1 N:d1
13. Bb6 d1c8+
14. resign (White cannot recover his material)

Final position:

1                    1
2   r . . . . k n    2
3   p p . . p . p    3
4   . . . p . p .    4
5   O . . O . . .    5
6   B O . . O O O    6
7   . . . K . N R    7
8    (n[ ]           8
  a b c d e f g h i

This chess variant has two main features that provide some fun: (1) the board changes (rows and columns are shifted left/right or up/down) which permits checks, piece pinning and the like, and (2) pieces may move very fast to other board edges via cage movements. Game by João Neto.