The kind of fiction I like to read the most, and that I tend to focus on here, falls under the broad umbrella of “speculative fiction.” I’ve never been entirely comfortable with the traditional genre labels of science fiction, fantasy and horror. The definitions that are most often applied to these genres seem so limiting, and they leave out a wide swath of really great books.

All three of these genres have one thing in common: The stories concern elements that do not exist in the so-called real world. In other words, they speculate about what might be possible but, in our everyday experience, isn’t.

In science fiction, the speculations must be grounded in the principles of science; they might not be possible now, but someday they could be, which is why science fiction is often set on future Earth or on another planet. The subjects of science fiction are space travel, dimensional travel, time travel, post-apocalyptic societies and technological innovations.

In fantasy, however, the speculations are usually based on magic and the supernatural. These speculations must follow rules, but they are not the rules of science. Generally, fantasy stories take place in imagined worlds (but not necessarily another planet) or on a fictional historical Earth.

Horror, on the other hand, most often takes place in the present day, in the world in which we live. But it introduces a fantastic or supernatural element, usually a monster of some kind. Horror also differs from fantasy in that it, by definition, should be frightening and dark.

But what about fiction that doesn’t fit neatly into one of these three categories? For instance, where would Neil Gaiman’s American Gods be classified? It is set in the modern-day world, but with its cast of mythical gods, it shades more toward fantasy than horror, although it does have horrific elements. Or what about David Mitchell’s excellent novel Cloud Atlas? This experimental novel is set in several different times, in the past, present and future, including a post-apocalyptic society. But it doesn’t read like traditional science fiction.

That’s where the label speculative fiction is useful. It covers any work of fiction that posits a “what if” question and then attempts to answer that question. That includes science fiction, fantasy and horror, plus narrower genres like alternate history and magical realism, as well as works that defy any neat label.

More contemporary writers who aren’t often associated with genre writing are stepping out of the bounds of literary fiction and into the realm of the speculative, and I’m glad because they are turning out some great works. For example, Michael Chabon’s The Yiddish Policeman’s Union is a fascinating alternate history, and one-third of Michael Cunningham’s Specimen Days is set on a future Earth, with aliens and space travel. I first started reading Jonathan Lethem via his genre-defying novels Gun, with Occasional Music, As She Climbed Across the Table and Amnesia Moon.

I like the speculative fiction label because it describes my favorite kind of writing but is much more open than the traditional genres. When I read speculative fiction, I can read hard sci-fi, traditional fantasy, contemporary horror or experimental literary fiction. The label also encourages good authors to experiment and stretch themselves without fear of being pigeonholed into an undesirable section of the bookstore. The stigma of writing about such subjects seems to have been dropped. For proof, just look at Cormac McCarthy‘s Pulitzer Prize-winning (and Oprah Book Club pick) post-apocalyptic novel The Road or Kazuo Ishiguro’s foray into science fiction, Never Let Me Go, which was shortlisted for the Booker Prize and named one of Time‘s 100 Best Novels of All Time.

Want to know more? Check out these sites:

• The Internet Speculative Fiction Database
• Speculative Fiction Wikiportal
• Speculative Fiction Blog