A state where any legal move worsens the position.
Why it matters
Zugzwang is being obliged to move when every move makes your position worse. Chess has no option to pass, and in simple endgames that rule alone decides games.
It is the reason the opposition matters, and the reason a tempo can be worth more than a pawn. In a position where neither side wants to move, the player who has to move loses.
See it on a board
White holds the opposition and Black has to move. Every king move gives ground, and the pawn walks in behind it.
Checked: the position really has the feature described.
How to play it
- Ask what would happen if the opponent could pass. If the answer is 'nothing', they are in zugzwang.
- Look for a waiting move that keeps everything as it is — a king triangulation, or a spare pawn move.
- Spend spare pawn moves carefully. Once they are gone, the zugzwang can turn round and land on you.
At each level
The same idea, said the way it is taught at each age.
Rook · ages 6–9
You are not allowed to pass. In simple endgames that is a weapon: put the opponent in a spot where every move is bad.
King · ages 10 and up
Keep spare pawn moves in reserve. In a mutual zugzwang the side with one tempo to burn wins, and the side without it loses the same position.
What goes wrong
- Using up spare pawn moves early, so you are the one obliged to move later.
- Assuming zugzwang only happens in endgames. It happens in blocked middlegames too, and it is worth playing for.
Questions people ask
- What is mutual zugzwang?
- A position where whichever side is to move loses, or spoils it. The whole game becomes about handing the move to the opponent, usually by triangulating with the king.