What is Castling in Chess ?

What is castling in Chess? How was my opponent able to “interchange” his king and rook? Why did my opponent move 2 pieces in one move? These are a few common questions to beginners. They revolve around the concept of castling. This term is quite new to beginners. Once I got ample of questions regarding castling. I decided to write this short article on it. Here is an article on how to set-up the chessboard.


Castling is a unique quality given to the king to reach safety. Generally, the king can move 1 square at a time, but in this scenario, the king can move 2 squares at a time and the rook moves beside it. But as it is a unique quality, there are some conditions

In Castling King and Rook are involved. A King moves Two squares and the Rook comes next to it. So as there are two Rooks, one has an option to castle in both ways. Castling is useful as it gets the king to safety and also the Rook gets developed. So we can call it a multi-purpose move. Now we move on to types of castling and the conditions required to castling.

1. Castling short.

When White moves his King to g1 and Rook to f1 it is a short castle. The reason it is called short castle is the rook moves only 2 steps in this case.

2. Castling long.

Here white King moves to c1 and a1 Rook moves to d1 it is called Long Castle.

3. Castling not possible due to Bishop controlling f1.

White cannot castle short here as Black Bishop controls f1 as King cannot move through a check to castle.

4. Castling not possible due to Check to King by Rook.

Black Rook gives a check to the white king. So it can only blockade or capture the rook or move his king. So white cannot castle.

5. Castling not possible due to Knight controlling g1.

As Knight controls g1 so white cannot castles short.

6. Castling now possible as controlling b1 does not matter to King.

As the Knight controls b1. It does not matter the king as it is not getting checked. So white can castle long in this case.

7. No pieces in between King and Rook.

Here as Queen is in between King and Rook. A player cannot castle long. It can castle short as there is no piece in between.


Also if the Rook or king has moved, the player cannot castle even if the Rook or King gets back to the original place.

Below is a video of castling by Chesscom

So I hope I’ve solved all the questions like What is castling in Chess? How are king and rook able to interchange?