This project seeks to understand the 'possible worlds, possible selves' (Carr, M., A. B. Smith, J. Duncan, C. Jones, W. Lee, and K. Marshall. 2010. "Learning in the Making." Rotterdam: Sense) afforded to children by collaborative imaginative play involving negotiation. We investigate how 3 and 4-year-olds achieve their ends through negotiation and collaboration in imaginary play. Preliminary findings suggest that the ability to influence the play appears to depend on the amount of 'negotiation capital' held by each child. Children engage in a process of 'brinkmanship' assessing how much 'negotiation capital' they hold at any time. The capacity to influence is, therefore, both individually and socially determined and time specific. The study raises questions about how adults can move from being 'solution fixers' with an emphasis on adult determined 'rules' as a way of settling differences of opinion in the nursery to engaging in a more reflective pedagogy where the adult 'tunes' to the child's collaborative play in action.