While the study of games and gaming has increased in International Relations in recent years, a corresponding exploration of play has yet to be developed in the field. While play features in several key areas – including game theory, videogames and popular culture, and pedagogical role-plays and simulations – little work has been done to analyse its presence in, and potentials for, the discipline. The aim of this article is to introduce the study of play to IR. It does this by demonstrating that play is political, and that it is at work across the global arena. Drawing on the deconstructive tradition associated with Jacques Derrida, its core contribution is a theorisation of play. The central argument developed is that play is (auto)deconstructive. By this I mean (1) that play precipitates an unravelling of any attempt at its conceptualisation, and (2) that this illustrates the value of a deconstructive approach to international theory. This claim is substantiated through an analysis of four key binary oppositions derived from Johan Huizinga's Homo Ludens. Having shown how play powerfully deconstructs its own conceptual foundations, I argue that a playful approach offers a robust challenge to entrenched assumptions in international theory.