Definition:Chess/Rules/Capture

Definition

If, during the course of its move, a chess piece is able to move into a square which is occupied by a piece of the opposite colour, it may do so.

Having done so, the piece of the opposite colour is then removed from the board and takes no further part in the game.

This is called capture.

Note that the behaviour of pawns is different.

Pawn

A capture in chess by a pawn works completely differently from that by any other piece.

It may happen in one of $2$ circumstances.

Normal Pawn Capture

If one of the $2$ diagonally adjacent squares towards the opposing player is occupied by an opposing piece, the pawn may move into that square and capture that piece.

En Passant Pawn Capture

Let pawn $a$ be on the player's $5$th rank.

Let pawn $b$ be of the opposite colour to pawn $a$.

Let pawn $b$ be on its starting position, on one of the files adjacent to the one occupied by pawn $a$.

Let pawn $b$ move forward $2$ spaces, in the process crossing over one of the squares which is under attack from pawn $a$.

Then pawn $a$, on its next move only, may move into that square crossed over by pawn $b$, and capture pawn $b$ "while it is passing".

This mode of capture is known as capture en passant.