This paper offers a critical assessment and some illustrations of an anthropological approach to the study of children's play. It argues that universal definitions of play are problematic and that therefore attention should be paid to the local definitions of play operative in any culture. This includes, importantly, the meanings that children attribute to and generate through their play. Drawing on ethnographic fieldwork the paper illustrates just one aspect of children's play: the different ways in which play facilitates power relations to be articulated, upheld, and challenged. In this sense play is revealed to be far from a frivolous activity. Instead, it is a serious medium through which children conduct their social affairs.