This paper puts forward an account of imaginative immersion. Elaborating on Kendall Walton’s thesis that imagining aims at the fictional truth, it first argues that imaginings are inherently rule- or norm-governed: they are ‘regulated’ by that which is presented as fictionally true. It then shows that an imaginer can follow the rule or norm mandating her to imagine the propositions presented as fictional truths either by acquiring explicit beliefs about how the rule (norm) is to be followed, or directly, without acquiring such beliefs. It proceeds to argue that to the extent that an imaginer follows this rule (norm) without holding such beliefs, she is more immersed in her imaginings. The general idea is that immersion in an activity is a matter of following rules or norms that apply to that activity without explicitly thinking about how to follow them, that is, without ‘doxastic mediation.’ Lastly, the paper shows that this thesis can explain various features associated with imaginative immersion, such as the sort of attentiveness it involves, the emotional response it generates, and its relation to spoilers.