Axiomatising Nash-Consistent Coalition Logic Helle Hvid Hansen, Marc Pauly Abstract: We add a rule for Nash-consistency to Coalition Logic, a modal logic for reasoning about the abilities and rights of groups in multi-agent systems. Rights of agents (constitutions) can be formalised using Coalition Logic, and the additional inference rule of Nash-consistency will guarantee that any multi-agent system implementing these rights will be stable, i.e., for any preferences the agents might have, there will be rights they can exercise such that no individual deviation will be profitable. We apply this logic to obtain a formal analysis of Gibbard's paradox, and we provide meta-theoretic results, in particular a complete axiomatisation.