Rough-and-tumble play is a distinctive form of behaviour. Although it appears superficially similar to fighting, there is considerable evidence that it differs in terms of causation and intent. A number of criteria for distinguishing the two forms of behaviour are cited, and evidence that children are able to use many of these criteria is presented. Rough-and-tumble play is considered in relation to dominance and affiliative relationships in children, and its possible functional significance in development is discussed. Rough-and-tumble play may exercise certain social skills, but as a form of behaviour it can also be used in socially manipulative ways, for example to inflict harm or achieve dominance. Implications for a social skills deficit model of aggressive behaviour in childhood are considered.