This is the second installment of a three part series of articles exploring the questions implied in the title of this Journal, Practising Social Change. In the previous article we set out our ideas about what constitutes social change and social change practice. Our premise is that social change practitioners are actually best understood as conducting ‘informed field experiments’ in the service of positive social change. The experimental nature of social change makes the practice very engaging but also very challenging. Since they are going together into unknown territory, social change practitioners and their entrepreneurial clients must be very resilient and resourceful and require unusually high levels of trust for the relationship to bear the strains that accompany large scale change.