In short: A defensive position the opponent can't break through, even though they have more material. With correct defense it is a draw.
The side with more material usually wins. But sometimes the defender builds a position that can't be broken. The king can't get in, the pawns can't advance, and no trade helps. Such a position is called a fortress, and with correct defense the game is drawn however long the attacker tries.
Queen against rook is normally a win for the queen, even when the rook has a pawn with it. Here the rook stands safely on the third rank, protected by the pawn, and White's king stays close. The queen can give check, but it can't get past.
Common fortresses
- Locked pawns. If the pawn chains are locked and there is no way to break through, the attacker's king never gets in.
- The king in the corner. Sometimes the defender's king can't be driven out of the corner. That happens, for example, in bishop endgames where the attacker's bishop doesn't move on the color of the corner square.
- Opposite-colored bishops. The defender builds a wall on the squares the attacker's bishop can't reach. Read about opposite-colored bishops.
Not the same as stalemate. In a fortress there are moves to make, and the game goes on. It is just that neither side gets anywhere. Read about when a game is a draw, and about more endgames under endgames.
Frequently asked questions
How do you know it is a fortress?
When the attacker gets nowhere: the king can't get in, the pawns can't advance and no trade helps. In endgames with few pieces we know today exactly which positions are drawn.
Which fortresses are most common?
Locked pawn chains that can't be broken, and a king in the corner that can't be driven out, for example in bishop endgames where the attacker's bishop is the wrong color.
Updated November 14, 2026