This article elaborates on the place of the United Nations Conference on Sustainable Development (UNCSD, also known as Rio+20) in a forty-year trajectory of international sustainable development negotiations, particularly through the processes placed in motion during the 1992 Rio Earth Summit event. The negotiation of the final UNCSD document also can be evaluated in its own right, and the article examines this process in the second section, keeping in mind the negotiating system in which the talks took place. The final section focuses on the process as a post-agreement negotiation and considers the role of the twenty-year milestone negotiations in shaping the sustainable development regime. The article explores in particular the role that consensus negotiated agreements have played as the regime’s decision-making procedure, and how this procedure has faltered as the complexity – including the number of issues, actors and obligations incorporated into the regime – has increased. Two elements from the Rio+20 outcome – a “take-it-or-change-it” facilitation approach of the Brazilian hosts and the adoption of a process to create “sustainable development goals” as a different means to focus international expectations – are presented as new directions for decision making in the regime’s next rounds of regime governance and regime adjustment negotiations.