Learn How to Spot Mate in 1: Hanging Piece
This puzzle comes from the Vienna Game and shows how quickly a game can end when king safety collapses. Even in a middlegame with plenty of material on the board, one loose piece or open line can create an immediate mating net. The key idea is that a seemingly active position can still be tactically lost if the king has no safe squares and a heavy piece can invade with tempo. Always check forcing moves first.