In the book the author presents from different perspectives what is understood by the phenomenon of children's play, why it is important, and how children's play challenge and stimulate the educator or caregiver in regard of educational values and practice, with the conclusion: play has to be taken seriously. A selection of theories is introduced to provide descriptions and explanations of play, as a background for putting forward certain requirements for what should be understood by play in early childhood education. Finally, a discussion of play as an educational remedy is presented, and at the end the important relations between play, experiences and self-concept development are outlined in relevance to teachers' professional play competence. The book is relevant to university academics teaching at bachelor and master programs of early childhood education; in addition to parents, teachers and caregivers in relation to children aged 0 to 9 years of age.