This paper is part of a series of interdisciplinary investigations in literary fiction and aims to identify the illocutionary force of the so-called “non-serious utterance” (Frege, Austin, Searle) of fiction makers on the theoretical assumption that the primary unit of an utterance’s meaning are complete speech acts (Austin), composed of an illocutionary force (Frege) and a propositional content (Searle). Based on philosophical analysis of non-serious and performative utterances of descriptive sentences, I formulate the fundamental hypothesis that the primary unit of non-serious utterances’ meaning is a complete declaration of the form F(in the language game x, P), whose illocutionary point is to create the extra-linguistic event represented in the propositional content of this speech act, in virtue of the linguistic meaning determined by the social conventions of fiction.