Mainstream stories are those that don't fit conveniently into one of the other genres, although they may borrow several elements from other categories. Because they don't belong to a specific genre, these stories don't have to conform to a specific set of rules. Generally, mainstream fiction is set in a contemporary setting, but some mainstream authors have used historical settings in their novels.

Whatever the time period, mainstream fiction uses story, setting, characters, and language to explore some aspect of the human experience in a realistic way. Plots are important in mainstream fiction, but there is room for more complex character development than in some of the other genres. Mainstream novels tend to appeal to a broad range of male and female readers.

Unfortunately, mainstream fiction can be harder to market, especially for beginning authors. Unlike science fiction or westerns or technothrillers, whose readers know what to look for in the stories they like, mainstream readers never get quite the same feel from one author to the next. That's not a bad thing, but it does mean that there is no built-in readership to target. Big-name authors like Amy Tan and John Irving can rely on their fan base and name recognition to help promote their works. New authors are often compared to a big-name author in marketing efforts to give readers a hint of what they can expect between the book's covers.

Fiction genres in their simplest sense are marketing categories, designed to help readers find the kinds of stories they like and so boost sales. Bookstores arrange similar stories together under these broad categories and subcategories; you won't find a fantasy novel in the western section, for example. Though most genres have been around for decades, even centuries, they are fluid enough to keep up with the demands of contemporary readers.

Mainstream fiction is sometimes categorized as commercial fiction, but that's a misnomer. Commercial fiction covers books that are expected to sell particularly well; they may be mainstream, or they may be genre works. Not all mainstream fiction will have terrific commercial success.

Finally, some people confuse mainstream fiction with literary fiction. Definitions of “literary” are necessarily subjective, and some mainstream work may also be literary work. In general, though, literary fiction may sacrifice plot to characterization, may contain more dialogue and less action than mainstream or genre fiction, and may offer several layers of meaning within the primary story. Mainstream fiction tends to be more straightforward and more plot-driven than literary fiction.