Cool, I've never played it before so where can I find it?
Cylindrical Board Theorem

Aida_Amin - You can play it on a regular board, you just imagine the A and H files do not stop at the side edges but are connected. I don't know if there is a place to play this online.

Aida_Amin Here is a link about the game. Basically the rules are the same, unless you want to modify or eliminate castling. There is a variant where you can make a "Null" move by moving a rook all the way around the board to it's starting point, but by default this is not allowed unless agreed to beforehand. If you are interested in playing a correspondence game with up to 3 days to move I'd take white as the lower rated player and pawn to B4 would be my first move. https://www.chessvariants.com/boardrules.dir/cylindrical.html
Aida_Amin Here is a link about the game. Basically the rules are the same, unless you want to modify or eliminate castling. There is a variant where you can make a "Null" move by moving a rook all the way around the board to it's starting point, but by default this is not allowed unless agreed to beforehand. If you are interested in playing a correspondence game with up to 3 days to move I'd take white as the lower rated player and pawn to B4 would be my first move. https://www.chessvariants.com/boardrules.dir/cylindrical.html
Oh, thank you!
Yes, the Cylindrical Board seems rather confusing at first, but as you get used to it, I suppose it becomes pretty easy. One thing is for sure: It's definitely a fun variant! Thank you again @ArthurEZiegler!

Did anyone notice that I published this on April Fools day? https://www.chess.com/blog/LogoCzar/cylindrical-chess
I played this game several times when I was a college freshman in 1969, so it is not really a new discovery. An interesting variant to standard chess.