Castling is a special move that aims to protect the king and give more freedom to the rook.
Learn how castling works and increase your chances of winning at chess!
Kingside Castling
As the name suggests, this form of castling takes place on the kingside.
Kingside castling consists of moving the king two squares towards the rook that’s on the h-file and moving that rook onto the last square the king has crossed (this means that the rook ends up right next to and on the opposite side of the king). By the end of this move, the king should be on the g-file and the rook on the f-file.
This move is only allowed when the king and the rook have not yet been moved from their starting positions. It is also impossible to castle when the bishop and the knight are in the way (haven’t moved from the starting position, for example). Simply put, the squares between the king and the rook need to be unoccupied, otherwise, it’s impossible to castle.
Image number 1: the king can move two squares towards the rook and the rook can leap over the king and stand right next to him.
Image number 2: the final positions of the kingside castling that just took place (the king on the g-file and the rook on the f-file).
Queenside Castling
As you would expect, this form of castling takes place on the queenside.
Queenside castling consists of moving the king two squares towards the rook that’s on the a-file and moving that rook onto the last square the king has crossed (this means that the rook ends up right next to and on the opposite side of the king, much like kingside castling, just on the other side of the chessboard). By the end of this move, the king should be on the c-file and the rook on the d-file.
As with kingside castling, the king and the rook must be in their starting positions to be allowed to execute this maneuver. Of course, it’s impossible to queenside castle if the queen, bishop, and knight are still between the king and the rook. All three squares between the king and the rook must be unoccupied for them to be able to carry out the maneuver.
Image number 1: the king can move two squares towards the rook and the rook can leap over the king and stand right next to him.
Image number 2: the final position of the queenside castling that just took place (the king on the c-file and the rook on the d-file).
Important note:
Castling is impossible when the king is in check or when one of the squares between the king and the needed rook is attacked by an opponent’s piece.
Thanks to the castling maneuver, the king will be better protected and the rook will be more free to move around the chessboard.