Abstract: I address the issue of how pretence emerged in evolution by reviewing the (mostly negative) evidence about pretend behaviour in non-human primates, and proposing a model of the type of information processing abilities that humans had to evolve in order to be able to pretend. Non-human primates do not typically pretend: there are just a few examples of potential pretend actions mostly produced by apes. The best, but still rare, examples are produced by so-called ‘enculturated’ apes (reared by humans) and among them specially those that have been systematically trained to use symbols (so-called ‘linguistic’ apes). A hypothesis that would explain the lack of pretence in apes is that they lack the mentalistic ability of theory of mind. However, in the last years apes have been demonstrated to possess relatively sophisticated social cognitive skills, some of them ontogenetically appearing in humans alongside with or even after pretend play. As a solution to the paradox, I discuss a model according to which pretence is supported by a mechanism capable of computing intentional relations with non-existing objects or properties (Intentional non-existence), as opposed to mechanisms computing intentional relations with existing, although not necessarily currently perceived, objects (Intentional availability). Apes possess the latter, which allows them to solve a variety of theory of mind tasks, but not the former, which typically prevents them from developing pretence.