How to play
Alice Chess

Named after Alice in Lewis Carroll's work Through the Looking-Glass. Chess on two boards with pieces moved between the boards.

Introduction

Alice Chess is played with one set over two boards. As pieces are moved, they transfer to the alternative board.

How to play Alice Chess Chess

Starting Position

One board is set up as normal, with the second board remaining empty.
Board is interactive - make a move

Moves of the Pieces

Pieces move as normal subject to the square on the alternative board being empty.

White pieces move to the alternative board
Board is interactive - make a move

Pieces can be played and captured on either board.

Pawn Promotion

Normal promotion rules, but only when a square is available on the alternative board for the promoted piece to be placed.

Castling

Castling can only be completed if space exists on both board. That is, the emtpy squares between the king and rook must be empty on the alternative board too.

Castling is available as the other board is clear
Board is interactive - make a move

Castling can only be completed if space exists on both board. That is, the emtpy squares between the king and rook must be empty on the alternative board too.

Castling is blocked on the second board
Board is interactive - make a move

En Passant

En passant is not available in Alice Chess as currently due to ambiguity regarding the rules.¹

¹ Support is under consideration and may be implemented for this variant.

Check and Checkmate

Check and checkmate is possible on either board. A king in check cannot escape by moving to the other board.

Checkmate - black is in check and any blocking movement would result in that piece being transferred to the other board leaving the king still under attack.
Board is interactive - make a move
Just Check - black can escape check by moving to a square that is not under attack on either board.
Board is interactive - make a move
Checkmate - black is now unable to escape check on board A, as moving to F7 would result in check on board B when it is transferred over.
Board is interactive - make a move

Stalemate

Stalemate conditions remain the same as Standard Chess.

Draw

Draw conditions remain the same as Standard Chess.

Winning

Checkmate your opponent on either of the boards.

Attribution