Decision support for impacts, adaptation, and vulnerability is expanding from science-driven linear methods to a wide range of methods drawing from many disciplines (robust evidence, high agreement). This chapter introduces new material from disciplines including behavioral science, ethics, and cultural and organizational theory, thus providing a broader perspective on climate change decision making. Previous assessment methods and policy advice have been framed by the assumption that better science will lead to better decisions. Extensive evidence from the decision sciences shows that while good scientific and technical information is necessary, it is not sufficient, and decisions require context-appropriate decision-support processes and tools (robust evidence, high agreement). There now exists a sufficiently rich set of available methods, tools, and processes to support effective climate impact, adaptation, and vulnerability (CIAV) decisions in a wide range of contexts (medium evidence, medium agreement), although they may not always be appropriately combined or readily accessible to decision makers.