In fashioning the new international climate change agreement to be adopted later this year in Paris, parties to the United Nations Framework Convention on Climate Change (UNFCCC)1 must address a range of legal issues. This brief outlines some of the key issues and concludes that: The Paris outcome arguably must include a core legal agreement constituting a treaty under international law; the exact title of the core agreement is legally irrelevant; the agreement can contain both binding and non-binding elements; the legal nature of parties’ nationally determined contributions (NDCs) is independent of where they are housed; and consistency with the UNFCCC does not require that the agreement adopt the same structure.