In this article, Michel Germain clarifies the rules of Alice Chess.
Please refer to the following definitions:
- Alice: the Alice Chess variation
- Half move: a move made by white or black
- Action board: the board on which a half move starts
- Landing board: the board on which the piece or pawn is 'teleported' to
- Teleport: the action in between two half moves, where the piece or pawn moved on the action board is tranfered from the to the landing board (also teleportation, piece teleport)
- Chess action: a half move and it's consequences for the others pieces on action board (capture, en passant, promotion, castle, check, etc.)
- Corresponding square: the square on the landing board which has the same coordinates as a square on the action board.
All legal half moves in a standard chess game are legal in Alice.
2a: A legal move under rule 1 becomes illegal in Alice if the corresponding square to which the piece or pawn is moved, is occupied.
2b: The teleport leaves the king in check on the action board.
Comment: This means that the only way to handle a check is to move the king or capture the checking piece or pawn. No piece or pawn may be moved to act has a shield because it is teleported after completion of the move (rule 3).
A half move in Alice is legal if it complies with rules 1 and 2. The half move is considered completed after all chess actions are complete.
The teleport phase is not a chess move nor a chess action. It starts after the completion of an half move.
The teleport phase consists of teleporting the piece or pawn moved on the action board to the corresponding square on the landing board.
The piece or pawn legaly teleported under Rule 4 has no history. When it lands on the corresponding square, the action board from where he came is immaterial.
The teleport action is not a chess move so it cannot trigger a chess action on the landing board. Otherwise it would be an infraction of rule 4.
The 'prise en passant' is an impossible action for the next half move on the landing board. Otherwise it will be an infraction of rule 5.
Comment: Let say hat white has a pawn on e5 and a black pawn is teleported to d5. To claim the right to take that pawn 'en passant', the palyer mus be ascertain that the last half move made on the landing board was d7-d5. But it can also be cxd5, exd5 or d6-d5. Base an argumentation on what has been playd on the action board is an infraction to rule 5. (It is the the equivalent of 'not gulty' sentence in court in opposition to 'innocent'.)
If castling is legal under rules 1 and 2, it is possible that the rook or the king squares (or the rook, knight or king squares) be occupied on the landing board because of rule 5.
Comment: Of course it is a neccesary that the half move made on the action board was castle. But this deduction triggers no conseqences (rule 4).