This course examines the theory and practice of complex multiparty cases. We will discuss various procedural mechanisms for aggregating multiple individual claims, including joinder, multidistrict litigation, non-mutual collateral estoppel, and extra-judicial mechanisms. Yet, our main focus will be on class actions, their justifications and problematic aspects, and the possible mechanisms proposed and used to render them more just and efficient. Grades will be based on a take-home examination.