I would like to use an AI engine to test how well the following chess variant would work: The rules are as in usual chess, except
- Castling is not possible; instead, the next rule takes its place:
- When the king is not in check, it can perform the following move: It can switch places with any piece of its own colour on the 8 neighbouring squares around it. Unlike castling, this move can be performed as many times throughout the game as you want. The following special rules apply:
- It cannot move itself into check by doing so (surprise!).
- It cannot move pawns to the player’s first rank (where pawns cannot be in ordinary chess either).
- If it moves pawns to the player’s eighth rank, that pawn will be promoted as usual.
- Any pawn on the player’s second rank can move one or two pieces forward, even if it has previously moved forward and later been moved back by the king. (This is in order to simplify the game so that you don’t have to remember which of your pawns have moved forward previously.)
The rules themselves do not really matter much. What I would like to know is how an AI engine would play against itself with this ruleset. Based on this, I hope to be able to make my own (human) assessment about how “deep” this variant is. I suppose it is possible to modify the rules given to engines like AlphaZero, MuZero, and Leela Chess Zero and ask the engine to teach itself the game as usual. But are there other, easier methods that do not require extensive rewritings of complicated engines?
I am aware of questions like this one and its answer, but it doesn’t seem that the answer can be adapted to support this variant.