PAWN

The pawn may move forward to the unoccupied square immediately in front of it on the same file, or on its first move, the pawn may move as in (a) alternatively it may advance two squares along the same file provided both squares are unoccupied, or (b) the pawn may move to a square occupied by an opponent’s piece, which is diagonally in front of it on an adjacent file, capturing that piece.

A pawn attacking a square crossed by an opponent’s pawn which has advanced two squares in one move from its original square may capture this opponent’s pawn as though the latter had been moved only one square. This capture is only legal on the move following this advance, and is called an ‘en passant’ capture.

When a pawn reaches the rank furthest from its starting position, it must be exchanged as part of the same move for a new queen, rook, bishop or knight of the same colour. The player’s choice is not restricted to pieces that have been captured previously. This exchange of a pawn for another piece is called ‘promotion’, and the effect of the new piece is immediate.