This article seeks to analyze three novels by Jean Genet: Our Lady of the Flowers (1943), Miracle of the Rose (1946) and The Thief's Journal (1949). Its main goal is to verify how the game with discursive techniques applied by Genet allows him to create a diegetic universe inspired by his private life and, therefore, to conduct a role-playing game, undertaken for ideological and ontological purposes. In order to carry out his plan, the author takes into account not only tools related to the poetics of a literary work but also selected aspects of an autobiographical pact aiming at persuading the reader of an "apparent truth" of the literary text. The study of these elements shows that the universe in Genet 's novels is, on the one hand, inspired to a certain degree by the reality, on the other hand, used to construct a narrative space where a continuous game with the truth and falsehood is located in the foreground.