Pawn can move in rank if already in 5th rank. Same as xiangi.
What strange chess rules can you think up?

If your opponent has no pieces left, (except his king) you must mate him in 13 moves, or it is a draw.

Every 5th move opponent must change sides.
Cool concept, but definitely some serious potetial irony. Imagine checkmate was going to be on your sixth move, lol.
Don't know if this has already been mentioned, but if the King is on a corner square when checked, he could "teleport" to another corner that isn't occupied.

Every 5th move opponent must change sides.
Cool concept, but definitely some serious potetial irony. Imagine checkmate was going to be on your sixth move, lol.
Well, if you were good you'd see it and not put yourself into a mate-in-one position going into a switch, right?

And you would be stabbing them why?
Each piece holds a miniature spear. Every time a piece captures another, that piece has to stab the piece it's capturing.

She would be able to deliver checkmate without support. Too much power for one peice unless you also allowed the King the same.

Every 5th move opponent must change sides.
Cool concept, but definitely some serious potetial irony. Imagine checkmate was going to be on your sixth move, lol.
Well, if you were good you'd see it and not put yourself into a mate-in-one position going into a switch, right?
Yes each opponent would make terrible moves to sabotage the other.

Free piece Friday rule: if the other player curses when playing on a Friday, you get a captured piece back.
chess is hard enough without messing with it, but variations are fun and can even help you (or hurt you) play normally.
At one time it was thought that rooks only could go 5 spaces instead of the full 8, dunno if that was ever proven for sure or just a guess or unconfirmed data.
I had a 3d set for a while, but no one would play it. Its was a fail game; you can't mate without a ton of material. It only had 3 levels instead of 8, I think 8 cubed would be unplayable entirely. Kind of neat to drop a pawn a level and get an instant passed pawn that is hard to deal with.