This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book discusses the diffractive nature of playwork and their ethnographic study, using Cultural Historical Activity Theory (CHAT) to research the dialectics of playwork. It considers the political and ethical aspects in her research on the power relations and advocacy of marginalised people (children) as the importance of the critical ethnographer. The book argues that playfulness provides a context for child-friendly research using a story-based experience termed as Narrative Journey. It describes second-order action research on childcare and playwork environments in the UK and Sweden. The book also argues that playwork practice and action research are natural partners, as they both are involved in practice-changing, balancing practice, action and research. It also considers power and social position, discussed through the playful setup of the 'upside-down' play session.