This is an Open access book. This work addresses the presence and participation of adults in play with children. Rather than discussing this issue on ideological ground, the international contributions build on empirical data and report research conducted in many different contexts and settings around the world. Responding to the many forms it takes, play is defined from different theoretical points of view. Amongst the topics addressed in the chapters are the ethics of participation, play with refugee children, democracy and play, multilingualism in play, development of play and imagination. For knowledge building on children's lives, childhoods and early childhood education and care, it is important to develop empirically and theoretically what processes come into play when children and adults play together, whether in play initiated and framed by adults or play initiated by children and to which adults try to gain entry. Primarily intended for researchers interested in play and intergenerational communication, the book is also valuable for professionals working with children in different kinds of early childhood settings.