When children play, they become creators, dreamers and artists. Sticks become wands, swords, dolls or snakes. This work addresses what play is, why it matters, and how modern life endangers children's play. Sally Jenkinson asks: what do children express in their play?; how does play develop empathy and social skills?; how are children influenced by inappropriate toys, TV and consumerism?; how does play develop children's imaginations?; why do children need adults who encourage play?; and how lively childhood players become creative adult thinkers?