Complex governance challenges the state- and IGO-centric focus in the study of global governance as well as its rational functionalist theoretical perspective. Complex global governance displays a common life cycle across issue areas that have become prominent in the post-Cold War decades: global health, climate change, and efforts to combat illicit financial flows. A transnational coalition expands the agenda of the complex through a political process that advances new issues and widens the agenda's scope. Although national governments and IGOs maintain important roles, resources available to the complex diversify. Governance complexes are able to target behavioral change in actors rather than relying on national governments and their compliance. A common pattern of evolution is enabled by economic and political globalization. Introducing this comparative and dynamic approach to complex global governance permits generalization that is often lacking in distributive approaches to international institutions.