Battle vs. Chess

Castling is done when you have a clear line between your king and a rook/castle. For this achievement you would need the enemy's king to be in the third column on the side you will be castling on, you would also need to not have moved your king or rook yet and there would have to be a clear line down the third or fourth column, depending on the side of the rook, to be able to put the enemy king in check. You would then need to move your king two spaces over next to your rook Getting all of this against an AI player though is very unlikely, so this achievement would be better of boosted.


This picture explains where the pieces will move to.