Alice Chess is chess variant played on two boards, moving pieces jump between them.
Game Rules
Alice Chess is played on two standard chess boards (A and B), with one set of standard chess pieces.
After each move, the moving piece is transposed to the corresponding square on the opposite board. Moves must be legal on the board on which they are made, and you can only move if the destination square is vacant on the opposite board. You can't move through check, even if that move would transport your king to the opposite board.
For example, here is the position after (in Alice1 game) white played e2-e4, black replied h7-h5, and white played d2-d4:
You are free to move using any piece, whether it is on the board A, or board B (note that piece moved on the board B will return to the board A).
Captures are allowed and are made on the same board, on which capturing and captured pieces are initially placed (transposition to the other board happens after capturing). For example, in the position above, black can play Rh8xh2, achieving the following position:
The game ends in checkmate - when the king is under check, and can not escape, or be protected. For example, here is the checkmate from some Alice2 game. Black king can not escape to c7, because it is not empty on the other board (note that white queen moved from h5 on the board B, if before the move it were on board A, it would be transposed and no checkmate would occur):
Castling is allowed (both king and rook are transported), en-passant is not allowed.
On SchemingMind Boards A and B can be seen side by side if there is room on the screen (they will be shown stacked on a smaller screen such as a mobile phone). The analysis board shows both boards superimposed on each other.
Alice Chess 2
Alice 2 is similar to Alice 1, however the black pieces start on Board B.