A cult film is any film that has a cult following, although the term is not easily defined and can be applied to a wide variety of films. Some definitions exclude films that have been released by major studios or have big budgets, that try specifically to become cult films, or become accepted by mainstream audiences and critics. Cult films are defined by audience reaction as much as by their content. This may take the form of elaborate and ritualized audience participation, film festivals, or cosplay. Over time, the definition has become more vague and inclusive as it drifts away from earlier, stricter views. Increasing use of the term by mainstream publications has resulted in controversy, as cinephiles argue that the term has become meaningless or "elastic, a catchall for anything slightly maverick or strange". Academic Mark Shiel has criticized the term itself as being a weak concept, reliant on subjectivity; different groups can interpret films in their own terms. According to feminist scholar Joanne Hollows, this subjectivity causes films with large female cult followings to be perceived as too mainstream and not transgressive enough to qualify as a cult film.:38 Academic Mike Chopra‑Gant says that cult films become decontextualized when studied as a group, and Shiel criticizes this recontextualization as cultural commodification.
In 2008, Cineaste asked a range of academics for their definition of a cult film. Several people defined cult films primarily in terms of their opposition to mainstream films and conformism, explicitly requiring a transgressive element, though others disputed the transgressive potential, given the demographic appeal to conventional moviegoers and mainstreaming of cult films. Jeffrey Andrew Weinstock instead called them mainstream films with transgressive elements. Most definitions also required a strong community aspect, such as obsessed fans or ritualistic behavior. Citing misuse of the term, Mikel J. Koven took a self-described hard-line stance that rejected definitions that use any other criteria. Matt Hills instead stressed the need for an open-ended definition rooted in structuration, where the film and the audience reaction are interrelated and neither is prioritized. Ernest Mathijs focused on the accidental nature of cult followings, arguing that cult film fans consider themselves too savvy to be marketed to, while Jonathan Rosenbaum rejected the continued existence of cult films and called the term a marketing buzzword. Mathijs suggests that cult films help to understand ambiguity and incompleteness in life given the difficulty in even defining the term. That cult films can have opposing qualities – such as good and bad, failure and success, innovative and retro – helps to illustrate that art is subjective and never self-evident. This ambiguity leads critics of postmodernism to accuse cult films of being beyond criticism, as the emphasis is now on personal interpretation rather than critical analysis or metanarratives. These inherent dichotomies can lead audiences to be split between ironic and earnest fans.
Writing in Defining Cult Movies, Jancovich et al. quote academic Jeffrey Sconce, who defines cult films in terms of paracinema, marginal films that exist outside critical and cultural acceptance: everything from exploitation to beach party musicals to softcore pornography. However, they reject cult films as having a single unifying feature; instead, they state that cult films are united in their "subcultural ideology" and opposition to mainstream tastes, itself a vague and undefinable term. Cult followings themselves can range from adoration to contempt, and they have little in common except for their celebration of nonconformity – even the bad films ridiculed by fans are artistically nonconformist, albeit unintentionally. At the same time, they state that bourgeois, masculine tastes are frequently reinforced, which makes cult films more of an internal conflict within the bourgeoisie, rather than a rebellion against it. This results in an anti-academic bias despite the use of formal methodologies, such as defamiliarization. This contradiction exists in many subcultures, especially those dependent on defining themselves in terms of opposition to the mainstream. This nonconformity is eventually co-opted by the dominant forces, such as Hollywood, and marketed to the mainstream. Academic Xavier Mendik also defines cult films as opposing the mainstream and further proposes that films can become cult by virtue of their genre or content, especially if it is transgressive. Due to their rejection of mainstream appeal, Mendik says cult films can be more creative and political; times of relative political instability produce more interesting films.