Backward pawn

Backward pawns are usually a positional disadvantage because they are unable to be defended by other pawns. Also, the opponent can place a piece—usually a knight, but it can also be a bishop or a rook—on the hole in front of the pawn without any risk of a pawn driving it away; such a square is called an outpost and can be very powerful, especially if there is no practical way to trade it off with another piece. The backward pawn also prevents its owner's rooks and queen on the same file from attacking the piece placed on the hole.

If the backward pawn is on a half-open file, the disadvantage is even greater because the pawn can be attacked more easily by an opponent's rook or queen on the file. Pieces can become weak when they are devoted to protecting a backward pawn, since their obligation to defend the pawn keeps them from being deployed for other uses.

The successful capture of a backward pawn can be disastrous for its owner. When a backward pawn is lost, its neighbors may become isolated, making them vulnerable, and the king's safety could be put in jeopardy, due to the opponent's pieces now having a clear path to move closer to it.