Zugzwang is a situation found in chess wherein one player is put at a disadvantage because they must make a move when they would prefer not. The fact that the player is compelled to move means that their position will become significantly weaker. A player is said to be "in zugzwang" when any possible move will worsen their position. The term is also used in combinatorial game theory, where it means that it directly changes the outcome of the endgame. Putting them in zugzwang is a common way to help the superior side win, and in some cases, it is necessary in order to make the win possible.