In short: Two pawns of the same color on the same file.
Pawns move straight ahead but capture diagonally. So when a pawn captures, it lands on the next file, and if a pawn of its own already stands there, you have doubled pawns: two pawns on the same file, one in front of the other.
Why are doubled pawns often weak?
- They can't protect each other. Pawns protect diagonally, and these stand right behind each other.
- The rear pawn is blocked by the front one and has a hard time moving forward.
- In the endgame, two pawns on the same file can be stopped by a single enemy pawn.
And why aren't they always?
When the pawn captured, it left a file behind, and that file can become half-open for your rooks. Doubled pawns can also guard important squares in the center. And whoever got the doubled pawns often got something else in return, as in the diagram above, where Black keeps both bishops. Many strong players are happy to accept doubled pawns if they get active pieces for them.
Read more about open and half-open files, isolated pawns and passed pawns.
Frequently asked questions
How do doubled pawns arise?
Pawns move straight ahead but capture diagonally. When a pawn captures, it lands on the next file, and if a pawn of its own already stands there, you get doubled pawns.
Are doubled pawns always bad?
No. They can't protect each other and are hard to advance, but they can give a half-open file for the rooks or extra control of important squares.
Updated October 31, 2026