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Special Moves

Castling, En passant & Promotion explained

Castling

Castling is a special move that involves the king and a rook.

There are two directions to castle in:

Kingside castling (castling short) consists of moving the king from E1 to G1, and the rook from H1 to F1.

Queenside castling (castling long) consists of moving the king from E1 to C1, and the rook from A1 to D1.

There are several conditions for a player to be able to castle:

In the above example the king cannot castle as the F1 square is attacked by the black bishop.

En Passant

En Passant (in passing) is a special pawn capture that occurs when a pawn has advanced two squares and ends up next to an enemy pawn. When this occurs, the enemy pawn can capture the pawn that had moved, capturing “in passing”.

The black D7 pawn moving forward two squares on its first move allows the white E5 pawn to capture it through the "en passant" rule.

Promotion

When a pawn reaches the 8th rank (or the 1st rank for black), it is promoted to a queen, rook, knight or bishop at the players choice. Pawn promotion can also be a capturing move.

Keep in mind that the choice is not limited to previously captured pieces, so if you promote another pawn, you can have multiple queens on the board.