In the game of chess, there is a maneuver called castling. This maneuver involves moving the king two squares closer to a rook situated on the same rank, and subsequently moving the rook to the square that the king traversed over. Because this formulation is too wordy to easily pronounce, the beginners usually remember a much simpler rule:
- Move the king two squares to the left or right.
- Jump with your rook over the king in the opposite direction.
Castling is the only move in chess in which two pieces are moved at once. If you move the king’s rook, it is referred to as kingside castling, while if you move the queen’s rook, it is called queenside castling. The notations used to denote these moves are 0-0 for kingside castling and 0-0-0 for queenside castling, which are used in both algebraic and descriptive notations.
Fun fact (or a short history lesson): The castling maneuver that is used in modern-day chess is derived from the “king’s leap” which is a move where the king can move two squares. This move was incorporated into European chess during the 14th and 15th centuries, and over time, it evolved into its current form during the 17th century. Despite this evolution, different regions had their own variations of the rules for castling, which were prevalent in Italy until the end of the 19th century.
It is crucial to know what conditions must be met to make castling possible, as it is a fundamental part of certain tactics to block the opponent from hiding their king by castling. Let’s remind the rules:
- Neither the king nor the rook has previously moved.
- There are no pieces between the king and the rook.
- The king is not currently in check.
- The king does not pass through or finish on a square that is attacked by an enemy piece.
It is important to note that the rules 3 and 4 are applied only to the king, not the rook. It happened even to grandmasters that they had been confused about the right to castle if the rook is under attack or if the rook should cross an attacked square. During the final match of the 1974 Candidates tournament between Viktor Korchnoi and Anatoly Karpov, Korchnoi had a query regarding the legality of castling when the rook involved in the move was under attack. He sought clarification from the arbiter, who confirmed that it was indeed a legal move. Following this confirmation, Korchnoi made the move, and shortly after, Karpov resigned.
If you play over the board, remember one important rule: Castling is considered a king move, so the king must be touched first! This is a part of the regulations set by the FIDE and implemented in the majority of chess tournaments. If the player touches the rook first, they are obligated to make a rook move instead. As per standard rules, the player can select any legal square as the destination for the king until it is released. Once the king is moved two squares, the player must commit to castling if it is a valid move, and subsequently move the rook accordingly.
Short version: Never use both hands to move the king and the rook simultaneously, as beginners sometimes do. Make a habit of playing with one hand only, always. First, move the king two squares sideways. Then, jump with the rook over the king. Finally, press the clock.
Castling can be turned into a surprise attack move if the circumstances are right. Have a look at the following game:
Please note that the white rook actually crossed the attacked square b2, which wasn’t against the rules. A king cannot do it, a rook can.
There are many examples of delivering a checkmate by castling. Let me show just one of them from our database:
What is in the name?
The majority of European languages use a term for castling that is derived from the Persian word “rukh,” such as “rochieren,” “rochada,” and “enroque.” Additionally, the terms used to refer to queenside and kingside castling are adjectives that denote “long” and “short” (or “big” and “small”) respectively.
So, we call it “rošáda” in Czech. And we distinguish between “velká” and “malá”.