The present chapter focuses on the methodology underlying the ‘Common Core of European Administrative Laws’ project in general, and its first research output on public authorities’ liability in particular. From this perspective, the chapter first introduces the current state of European tort law and the scholarly initiatives focusing on it, before presenting the basic outlines and distinctive features of the ‘Common Core’ approach and the rationale behind the three-level responses, which is one of the distinctive features of the whole project. The chapter thus sheds light on its potential contribution to European debates on public liability and comparative tort law.