In this chess position, having to move is the whole problem
Picture an endgame where a player's pieces are all stable — until it's their turn. Every single legal move they have available makes their position strictly worse than simply staying put, but chess doesn't allow passing. What's this situation called, and why does it matter?
Reveal the answer
It's called zugzwang, German for 'compulsion to move.' It shows up constantly in king-and-pawn endgames, where a king guarding a square must eventually step aside and let the opponent's king or pawn through, losing the very thing it was protecting. It's one of the few places in chess where simply being forced to act, with no good action available, is itself the losing move.