Pawn

Each player begins with eight pawns. In the starting position, White's pawns occupy the second horizontal row, called the second rank, and advance toward the eighth rank; Black's occupy the seventh rank and advance toward the first. Unlike the other pieces, a pawn can never move backward.

• Normal move: it advances one square straight ahead if that square is empty.
• First move: from its original square it may advance one or two squares, provided both squares are empty.
• Capture: it takes an enemy piece one square diagonally forward. It cannot capture a piece directly in front of it.
• En passant: if an enemy pawn advances two squares from its original position and lands beside it on the same rank, the pawn may capture as though the enemy had advanced only one square. This option exists only on the immediately following move.
• Promotion: on reaching the farthest rank, the pawn is replaced on that move by a same-color queen, rook, bishop, or knight. The choice is not limited by previously captured pieces.

The pawns and other pieces remaining on the board are collectively called material. The pawn is commonly used as the reference unit and is conventionally assigned one material point. That point is not a point in the game's result. The scale is only a guide: the position, distance from promotion, and the pawn's role can greatly change its practical importance.