In the last decade, Responsible Research and Innovation (RRI) has earned a prominent position in policy spheres by offering forward-looking approaches and a framework for reflecting on the societal impact of research and innovation. Nevertheless, RRI remains an immature and relatively narrow area of inquiry, with a top-down approach and guided by standardized principles. Further, the field lacks focus on how researchers, firms and other actors actually perform responsible research and innovation. By unveiling the heterogeneity of responsibility practice, this special issue broadens RRI's scope in two ways. First, by expanding RRI's narrow focus on the research processes towards an approach that also takes into account how new knowledge and new ideas are becoming research-based innovations in society. Second, by including a wider spectrum of responsible innovation processes, and not only those that are research-driven. This special issue includes 10 investigations of heterogeneous responsible innovation practices that cross sectors and regions. Using the lessons these contributions teach, we close the issue with suggestions for a new multidimensional, multi-scale avenue for RRI.