Zugzwang — what it means in chess
A position where any move worsens your stance, but you must move.
A position where any move worsens your stance, but you must move.
[[board startfen="4k3/8/4K3/4P3/8/8/8/8 b - - 0 1" caption="Zugzwang: Black to move — and every legal move loses ground that standing still would keep. The compulsion to move, chess's strangest liability, played here all the way to the queen it costs." pgn="Kf8 Kd7 Kf7 e6+ Kf8 e7+ Kg7 e8=Q" notes="The rules never let you pass. Sometimes that single fact decides the game. Black must move, and every option gives ground — the definition of zugzwang, in motion. The king steps aside… …and White's king advances into the vacated influence at once. Black fights for the front squares — — but the pawn advances with check: the space Black was forced to yield, collected with tempo. Driven back again. And again the pawn steps forward with check — each Black move having handed White exactly the tempo needed. The last shuffle. Promotion. Trace it backward and every White gain began with a Black move Black did not want to make. If Black could have passed even once, the defense holds; the obligation to move was the entire losing material."]]
Zugzwang — German for "compulsion to move" — is the situation where the obligation to move is itself the losing condition: every legal move worsens the position, and the player would be safe if only the rules allowed a pass. They never do, and that refusal is one of chess's deepest structural facts. In most of the game, having the move is an asset — a tempo, a chance to act. Zugzwang is where the asset's sign flips, and whole branches of endgame theory live on the far side of that flip.
The Endgame Society glossary defines more than 240 chess terms — rules, notation, tactics, strategy, pawn structures, endgames, and openings — in language a beginner can act on rather than dictionary shorthand.