Changing the world in court – this is what strategic litigation is all about. In an interdisciplinary study, Lisa Hahn examines under which conditions such change can be achieved and why the collective mobilization of law is essential for this. Strategic litigation unites people in a litigation collective and thus contributes to overcoming individual barriers to access to justice. Lisa Hahn reaches this conclusion by drawing on legal mobilization theory, through a historical reconstruction of seminal court cases and by examining strategic litigation as an instrument for implementing the human right to access to justice. Empirical case studies on migration and surveillance provide unique insights into litigation collectives.