Since our founding in 1993, the work of the Grassroots Policy Project (GPP) has focused on organizational practices that help groups imagine and move toward fundamental social change. We draw lessons from the history of transformative social movements and from movement theory, but the focus of our work is putting ideas into practice. It is through the organizing experiences of the groups around the country with which we work that we have drawn some lessons – none of them hard and fast, all of them subject to exploration, debate, and re-examination – about what kinds of organizational practices have the power to change the world.