The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) faces various challenges, as highlighted in chapters 2 and 3. How can biodiversity regime complex initiatives be coordinated and integrated to improve the science-policy interface? How can an intersubjective understanding of the contents of biodiversity science be achieved in a setting of di¿erent knowledge systems, competing policy priorities, and rival agendas? How can intergovernmental dynamics be combined at di¿erent scales in selecting and assembling knowledge? The Platform design is the result of a relatively long and laborious process of international negotiations (2008 to 2012) in the context of a biodiversity regime complex characterized by a large number of international conventions of various scopes (both general and thematic) and at all scales (global, regional and even bilateral) (see chapter 2). IPBES is governed by an array of rules and procedures which have been developed throughout this slow genesis (2008 to 2012) and regularly enhanced in every plenary session. These rules are related to the decision-making mechanism but also to the working procedure to provide a framework for and implement scienti¿c assessments and other activities linked to the IPBES work program. The aim of this chapter is to provide a broad overview of the dynamics of governing IPBES on two aspects, i.e. institutional functioning and its core business, namely the production of assessments on biodiversity issues. When striving to understand the dynamics of IPBES, we focus on some aspects that have been controversial among the participants, including the question of the legal status of IPBES. The plenary sessions highlight the IPBES functioning process.1 Generally, an IPBES Plenary agenda is structured as follows. Firstly, the organizational matters aim to ¿nalize the agenda, to specify the membership of the Platform and validate the presence of observers. The representatives' credentials