The Hybrid Justice project analyses the impact of ‘hybrid’ domestic-international criminal justice mechanisms in post-conflict and transitioning states. These courts and tribunals feature varying combinations of domestic and international staff, operative law, structure, financing and rules of procedure. Early hybrids were established in East Timor, Sierra Leone, Cambodia, Bosnia and for Lebanon, before the establishment of the International Criminal Court (ICC) was expected to make hybrid mechanisms redundant. However, the shortcomings of the ICC have led to the resurgence of hybrids – in Senegal, Kosovo, Central African Republic, South Sudan, and proposed for Colombia, DRC, Syria, Sri Lanka, Ukraine and ISIS. Because hybrids were thought to be a relic of pre-ICC justice, there has been little academic research on their impact, meaning practitioners currently in the process of establishing hybrids have few guidelines on how to design effective mechanisms. Working with the Wayamo Foundation, a leading international justice NGO, this project brings together experts on hybrids from academia, the ICC and the hybrids themselves to 1) produce an authoritative comparison of past and present hybrids; 2) critically evaluate the impact of hybrids on resilience in post-conflict and transitioning societies, including within wider programmes of transitional justice; 3) produce guidelines for the establishment of future hybrids; 4) produce policy advice for the ICC on how hybrids should be evaluated in terms of complementarity requirements.