The adoption and entering into force of the Paris Agreement is a welcome occasion to re-assess the legal foundations of emissions trading and, in particular, the nature of ‘carbon rights’. Cap-and-trade (‘allowances’) and baseline-and-credit (‘credits’) represent the main emission trading approaches, the former imposing compliance obligations, the latter stipulating voluntary action to reduce and monetize emissions. Each approach comes with legal characteristics and raises legal questions concerning property rights and protection, taxation, and financial regulation, on the one hand, and the proper recognition of individual mitigation efforts (in the context of environmental services) and participation rights, on the other hand. This article places the different type of rights in the context of their creation, purpose, and function.