Formally, state parties are equal in all United Nations negotiations. In theory, every state, regardless of its size, economic or political power, has the same opportunities and rights to participate. Nevertheless, United Nations negotiations, such as those on climate, are often considered highly unequal in practice. Many states struggle to meaningfully engage in complex and highly technical multilateral negotiations, including because their delegations are smaller. Here we examine delegation size in United Nations climate negotiations through a procedural justice lens. Starting from normative principles of procedural justice, we argue that equitable negotiations demand the capability of all parties to send a