The word ‘playground’ is one which invites reflection. ‘Play’ is a complex notion. It is associated on the one hand with fun, romping, teasing and intricate rituals of behaviour which have been observed in animals and humans all over the world. On the other, it is associated also with danger —the moments when play spills beyond the confines of fun into something more challenging, the growl which becomes a bite, the cuff which lands as a punch, the songs which sharpen into screams. ‘Ground’ conjures up a sense of space, the equivalent of a field-open, but bounded; free, but constrained. Once we pause to reflect, we realise that we know little about the meaning of ‘playground’ within schools, and that we are very ignorant about the ways in which pupils use this space to explore the intricacies of the positive and negative in human relations. The word ‘playground’ is full of contradiction and paradox, and the behaviour of pupils must be closely observed if we are to learn what is actually going on, and to engage with pupils in solving the problems which arise.