Fanfictions are fictional stories written by fans, based on TV shows, movies, literary works, videogames: fans borrow from previously existing characters and universes to develop new plots. From a post-structuralist perspective, this study follows two complementary lines of research: first, it examines fanfiction in light of the theoretical-conceptual propositions of André Lefevere (1982, 1992) — notions of refraction/rewriting and patronage; second, it dialogues with Jacques Derrida s Archive Fever (1995), and his rich contributions to the notion of archive. This research focuses particularly on investigating the following effects of this type of rewriting: how does fanfiction disrupt the traditional modus operandi of literary systems? How do fan narratives destabilize, to a greater or lesser extent, identities of other rewritings, such as the pastiche? Considering the specificities of the genre, how can one characterize it from a philosophical perspective? This research shows in particular that (a) fanfiction can be thought of as a type of rewriting in Lefevere s terms, fan narratives destabilize some patronage control mechanisms, there are differences between fanfiction and pastiche, as well as between these and other forms of rewriting, such as translation, adaptation and literary criticism; and (b) fanfiction can be productively conceived as an archontic rewriting, in Derrida s terms, as it is used by so-called minorities as a way of expressing dissatisfaction and a path to representativity (DERECHO, 2006), while still corroborating the tension between conservative and institutive forces, as proposed by the philosopher in his archive theory. Finally, excerpts of fanfictions from three different fictional universes are analyzed, in light of the theories of Lefevere, Derecho and Derrida, in order to illustrate and reinforce the theoretical discussions presented.