Castling

	The Basics of Chess
The Moves
Castling

The King is the most important piece in the game.
If the King is checkmated (as you'll learn in the
check and checkmate section) the game is over.

There is a special move - Castling - used for safeguarding the King against attack.
Castling is not actually one move, but two - one move with the King and one with one of the Rooks.
Even though Castling consists of two moves, they are both made in one turn.

Since there are two Rooks, there are also two way you can castle:

on the King-side - with the King and the Rook which initially is placed
to the right of the King (ie. on the King-side);

on the Queen-side - with the King and the Rook which initially is placed
to the left of the Queen (ie. on the Queen-side).

The top diagram shows the position before the King-side Castle (for both White and Black).
The bottom diagram shows the position after King-side Castling.

Here the top diagram shows the positions before Queen-side Castling and the bottom diagram shows the positions after Queen-side Castling.

Requirements for Castling

Castling is permanently impossible if:
- The King has already moved;
- The Rook intended for Castling has already moved
  (this means we can still Castle with the other Rook provided it hasn't moved).
Castling is impossible for the time being if:
- The squares between the King and Rook intended for Castling are not all vacant;
- The King is in check;
- The King has to pass over a square controlled by an enemy piece;
- The King will land on a square controlled by an enemy piece.

The Basics of Chess

The Moves

Castling