The concept of world order is used in this chapter to refer to the distribution of power and authority in international relations on the global level. It refers to the structure of power and authority in international relations, and it pertains to an ideal configuration of power and authority that is linked to universalistic liberal goals. The liberal world order, also known as the rules-based international order, is characterized by structured and rules-based interactions founded on the principles of liberal internationalism. However, the liberal world order is currently facing challenges to its existence, fundamental principles, and operational effectiveness. Russia and China have been challenging its limits, leading to increased criticism. Despite these challenges, there is currently no viable alternative to the existing system. The chapter also discusses theoretical approaches to understanding world order, emphasizing the state-centric nature of the international system and the influence of norms and rules. The dominant interpretation of the major powers in the system shapes the world order, and they are the (regional) units of analysis in an equilibrium discussed in this chapter. The world order is not without flaws, and there is a need to consider alternative perspectives and approaches. The chapter discusses the global equilibrium of the rules-based international order from the perspective of its main players: the USA, China, the EU, Russia, and the Global South. The legitimacy of the international order relies on the adherence of its players to its norms, but this adherence is subjective and depends on individual, subjective evaluations, and the current imbalance caused by the war in Ukraine raises concerns about the legitimacy of the existing world order.