# Definition:Chess/Pawn

(Redirected from Definition:Chess Pawn)

## Definition

A pawn may move in the following modes.

$(1): \quad$ It may move one square towards the opposing player, if and only if that square is empty.

$(2): \quad$ If it has not yet been moved, and if and only if both of the squares are empty, it may move $2$ squares forward instead of $1$.

Some authorities do not classify the pawn as a piece.

### Promotion

If a pawn moves onto the square on the final rank, it is then exchanged for any other type of piece which replaces the pawn on that square.

This is called promotion.

The player of that pawn decides which piece to replace it with, which may be neither another pawn nor a king.

If it is promoted to a queen (which is usual, the queen being the most powerful piece), this operation is colloquially referred to as queening.

### Capture

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.