John Hancock argues that Hollywood films are not pure genres, because most Hollywood movies blend the love-oriented plot of the romance genre with other genres.^[1] Staiger classifies Andrew Tutor's ideas that the genre of film can be defined in four ways. The "idealist method" judges films by predetermined standards. The "empirical method" identifies the genre of a film by comparing it to a list of films already deemed to fall within a certain genre. The Apriori method uses common generic elements which are identified in advance. The "social conventions" method of identifying the genre of a film is based on the accepted cultural consensus within society.^[1] Jim Colins claims that since the 1980s, Hollywood films have been influenced by the trend towards "ironic hybridization", in which directors combine elements from different genres as with the Western/Science fiction mix in Back to the Future Part III.^[1]

Genre is always a vague term with no fixed boundaries. Many words also cross into multiple genres. Recently, film theorist Robert Stam challenged whether genres really exist, or whether they are merely made up by critics. Stam has questioned whether "genres [are] really 'out there' in the world or are they really the construction of analysts?". As well, he has asked whether there is a "... finite taxonomy of genres or are they in principle infinite?" and whether genres are "...timeless essences ephemeral, time-bound entities? Are genres culture-bound or trans-cultural?". Stam has also asked whether genre analysis should aim at being descriptive or prescriptive. While some genres are based on story content (the war film), other are borrowed from literature (comedy, melodrama) or from other media (the musical). Some are performer-based (theFred Astaire and Ginger Rogers films) or budget-based (blockbusters), while others are based on artistic status (the art film), racial identity (Black cinema), location (the Western), or sexual orientation (Queer Cinema)^[2]

Many genres have built-in audiences and corresponding publications that support them, such as magazines and websites. Films that are difficult to categorize into a genre are often less successful as such film genres are also useful in areas of, criticism and consumption hollywood story consultant originality and surprise."^[3] Some screenwriters use genre as a means of determining what kind of plot or content to put into a screenplay. They may study films of specific genres to find examples. This is a way that some screenwriters are able to copy elements of successful movies and pass them off in a new screenplay. It is likely that such screenplays fall short in originality. As Truby says, "Writers know enough to write a genre script but they haven’t twisted the story beats of that genre in such a way that it gives an original face to it".^[4]

Screenwriters often attempt to defy the elements found in past works, as originality and surprise are seen as elements that make for good film stories.^{[citation needed]} For example, European-filmed spaghetti westerns changed the western film genre by eschewing many of the conventions of earlier Westerns.^{[citation needed]}

There are other methods of dividing films into groups besides genre. For example auteur critics group films according to their directors. Some groupings may be casually described as genres although the definition is questionable.^{[citation needed]} For example, while independent films are sometimes discussed as if they are a genre in-and-of themselves, independent productions can belong to any genre. Similarly, art films are referred to as a genre, even though an art film can be in a number of genres.

Genre can also be distinguished from film style, which concerns the choices made about cinematography, editing, and sound.^{[citation needed]} A particular style can be applied to any genre. Whereas film genres identify the manifest content of film, film styles identify the manner by which any given film's genre(s) is/are rendered for the screen. Style may be determined by plot structure, scenic design, lighting, cinematography, acting, and other intentional artistic components of the finished film product.^{[citation needed]} Others argue that this distinction is too simplistic, since some genres are primarily recognizable by their styles.^{[citation needed]} Many film historians and film critics debate whether film noir is a genre or a style of film-making often emulated in the period's heyday.^{[citation needed]} Indeed, film noir films from the 1940s and 1950s were made in a range of genres, such as gangster films, police procedural dramas, and thrillers.^{[citation needed]}