From the erosion of state legitimacy in Lebanon to the use of smartphones in Kyrgyzstan, from a Polish suburb to the music scene in Azerbaijan, this volume attempts to explain why, in a variety of world regions, a substantial number of people tend to ignore or act against state rules. We propose to look at informality beyond simplistic associations of the phenomenon with a single category such as "informal labour" or "corruption". By doing this, we propose to look for a correlation between the emergence, and persistence, of some informal practices and the quality of governance in a given area. We also suggest that a better understanding of the variety of informal practices present in a region can help conceptualising more adequate interventions and eventually improve the socio-economic conditions of its inhabitants.