Regimes pertain to delineated areas of rule-governed activity in international relations, such as implicit or explicit principles, norms, rules and procedures governing expectations among actors. While the international system is anarchic without a central ruler, regimes help bring order and facilitate cooperation to address global problems. Regime characteristics include their strength, scope, organizational form and allocation mode. Different regime types are defined by levels of formality and the degree of convergence among actor expectations. The emergence and effectiveness of regimes can be studied through structural, game-theoretic, functional and cognitive approaches. Regimes help manage globalization by changing how states interact and their interests.