Like never before, designers are improvising. They’re finding un-inscribed rules in frames of reference as didactic as form fields, as motley as urban landscapes. This section of “LEAP Dialogues: Career Pathways in Design for Social Innovation” investigates the “what” of practicing social innovation. Not comfortable resting on the “what” that is, the practice of social innovation stretches our understanding of what can be. And suggests a bit of improv is required.