In short: A pawn with no pawns of its own on the files next to it.
Pawns protect each other diagonally forward. So a pawn with no pawns of its own on the files next to it can never be protected by another pawn. It is called isolated.
The weaknesses
- It has to be protected by pieces. Pieces guarding a pawn do nothing else.
- The square in front of it is an outpost. No pawn can chase away a piece standing there. A knight is especially happy there.
- It gets weaker over time. As the pieces are traded off, what often remains is a lonely pawn that is easy to attack.
The strengths
The isolated pawn has advantages too. The files next to it are open or half-open, and the rooks can work there. An isolated pawn in the center gives the pieces room and can support an attack. That is why strong players are happy to play with an isolated pawn as long as there are many pieces left, and try to avoid the endgame.
The isolated queen's pawn
An isolated pawn on the d-file is often called an isolated queen's pawn. It arises in many common openings and has a whole theory around it. The rule for the player facing it: blockade, trade off, attack.
Read more about doubled pawns, passed pawns and open files.
Frequently asked questions
What is an isolated queen's pawn?
An isolated pawn on the d-file. It is common in many openings. In the middlegame it often gives the pieces free play, but in the endgame it easily becomes a target.
How do you play against an isolated pawn?
Blockade it by putting a piece, preferably a knight, on the square in front of it. Then trade pieces, and attack the pawn once it no longer has much support.
Updated October 31, 2026