We all recognise that world is inherently complex but what does this mean? From a theory perspective it means that it is an open system where the agents and the environment coevolve and influence each other. This means that traditional approaches that are based on analysis no longer have agency and will not allow us to make sense of the world. It is not about throwing the old out but understanding where existing practices are applicable and where we need to think a new. This mini-book started out as a series of papers that were experiential in nature and which were intended to provide an introduction to complexity theory, the Cynefin framework in particular and some of its related practices. These are simple practices that allow us to make sense of a complex world and allow us to establish what actions are appropriate and how we should act.