I can't remember a time when I didn't adore speculative fiction. From the earliest days of my misspent youth I was a Star Trek fan (the original series, of course. This was the 70s). As soon as I learned to read, I worked my way through my father's vast science fiction library and by the time I was in eighth grade, I'd discovered fantasy as well. I've read a couple of thousand books in my lifetime, perhaps more. From a reader's point of view, the classification of genres might seem pointless--either you like a book or you don't.

From an author's point of view, it's vitally important to know what genre you're writing in if you want to successfully market your book, for certain genres are dominated by certain readers. Without knowing your target audience, it's virtually impossible to create a successful marketing plan.

However, long before I was an author, I already thought in terms of genre. Science fiction fans in particular love to label things and put them into little boxes. The entire genre debate has really come to a head over the last few years, so I thought I might try to shed some light on the murky waters, though I'll probably just stir up mud. Anyway, here is how I would classify the various genres.

I've already used the words speculative fiction once in this article. When people ask me what I write, it's the answer I give. Years ago, speculative fiction had a different definition than it does today. It used to be science fiction without the science.

Part of the confusion might be that science fiction (abbreviated with a capital SF) and speculative fiction (abbreviated by a lower case sf) have always been linked as each contain speculative elements. Yet today, speculative fiction has come to take on a new definition.

But first, what the heck is a genre anyway? This simple question needs to be answered before we move on. A genre is an arbitrary classification (as are ALL classifications), in which books (or movies or t-shirts or whatever) can be placed into neat little piles. According to the Miriam Webster dictionary, a genre is "a category of artistic, musical, or literary composition characterized by a particular style, form, or content". That clears it up, doesn't it?

Think of each genre as a section in your local video store; comedy, western, action, science fiction, these are all examples of genres. The largest division of a genre would be the genre itself, after which the genre would be broken down into subgenres, which define more specific categories--boxes within boxes. The only problem with the aforementioned neat little piles is they're not so neat. There is much crossover between genres even at the best of times, and these days, you can't take anything for granted.

Back to speculative fiction, which is not actually a genre at all, but a supergenre. That is, a group of genres held together by a common feature, in the case of spec-fic, a "fantastic" element. I don't mean fantastic as in really awesome, but more as something that doesn't exist in the world today, whether it be a fantasy element, such as a genie, a science fiction element, such as a time machine, a horror element, such as a demon or even something as simple as ESP, which has yet to be proven. Once an author adds to a book something outside of everyday existence, he (or she) has entered the realm of speculative fiction.

Take for example a romance. Boy meets girl...they fall in love...get separated...and finally, after much hoopla, get back together. It's a common enough plot in romance. The fact is, there's nothing wrong with the plot, but it can't be called spec-fic, because it can happen. There is no fantastic element in the plot (even if it happens to be a fantastic story). Now, if a particular romance were to take place on a space station in the future, you've introduced a speculative element, in which case your story becomes either science fiction romance, or romantic science fiction, depending on which element is strongest.

The three main genres that make up the speculative fiction supergenre are science fiction, fantasy and horror. There are more, but we'll start with those. Even within those big three, there is crossover. Anyone who's seen the movie Alien knows it's a science fiction movie, yet it definitely contains horror elements. The same could be said of Pitch Black. Another movie I like to bring up is Outland, starring Sean Connery--a crime drama that happened to take place on a moon of Jupiter. It's a sci-fi cop story. But you'll find it in the science fiction section of your local video store (or would have many years ago).

Having named the three main genres of spec-fic, I'll now attempt to define them.

Science fiction is any movie or book based on science or more technically, one in which the plot can not exist without science. In other words, we can get from where we are to the background of that book (or movie) without breaking scientific rules. Mind you, as science changes, we must use the rules that were available at the time of writing. I've recently finished reading a seventy-year old sci-fi novel called Maza of the Moon by Otis Adelbert Kline. It was, at points, patently ridiculous, but at the time the author couldn't possibly know that. Back then, it was entirely possible there were civilizations on the moon, hidden from our telescopes, because they were underground. If that book had been written today, I could only consider it fantasy, since much of what happened was not possible. In 1930, when Mr. Kline penned Maza of the Moon, it was science fiction and remains so today.

Other examples of science fiction would be Jurassic Park (cloning a dinosaur from DNA taken from biting insects trapped in amber is a feasible endeavor, even if we don't have the technology to do it), The Andromeda Strain, The Time Machine, Dune--anything where science makes the story an eventual possibility can be considered science fiction.

Fantasy, on the other hand, doesn't have to be possible, even if good fantasy is plausible. Fantasy should rest on rules, even if those rules are different from those of our own universe. For example, in Watership Down, animals had the ability to talk. It's not science fiction, because animals can't talk. Not as we do anyway. Virtually anything that introduces magic is considered fantasy. The exception to this is when the magic is explained by scientific means. It was Arthur C. Clarke who said, "any sufficiently advanced technology is indistinguishable from magic" (Clarke's Third Law). Which means, if you know "how" it was done, it's no longer magic and thus might fall into the realm of science fiction.

My favorite example of this device is in the Jack Chalker series Soul Rider. The books start off as a fantasy, but soon the "magic" is explained in scientific terms and by the third book of the series, Chalker manages to morph magic into the realm of science. In some Roger Zelazny books (Madwand and Jack of Shadows to name but two), technological and magical civilizations coexist on the same planet. These books must both be considered fantasy, for once a fantasy element enters a science fiction book, it's no longer SF (even though it remains sf!). Even Star Wars, with the introduction of the force, leans to fantasy and many consider it to be science fantasy. This isn't a recognized genre, but rather a bastardization, because most people aren't comfortable calling movies with space ships and aliens fantasy.

Horror is different from both science fiction and fantasy, in that horror is defined less by whether something is possible or not, and more by the emotion the author is trying to elicit from his readers. The horror genre is about writing something scary, that's all there is to it. That's why horror is easily crossed with either science fiction or fantasy. If your movie or book is scary enough, it becomes horror by default, even though it might be found in another genre as well (see Alien above).

As if this wasn't all confusing enough, each of the genres above has subgenres. Take for example space opera. Space opera is arguably the simplest form of science fiction, an action adventure that takes place in space. Aliens trying to take over the Earth, with lots of ray guns and explosions, rescues and battles--that's space opera. Buck Rogers and Flash Gordon are perfect examples. Fantasy has a version of this too called swords and sorcery. It's an exact analog of space opera; battles, magic, fighting, rescues, action and that's about it.

Star Wars might be a good example of space opera, Conan the Barbarian of swords and sorcery. Mind you, just because these books are simple, doesn't mean I'm judging them--just classifying them, which is different. I've often greatly enjoyed reading space opera and swords and sorcery, even though many consider those subgenres to be all but played out. The truth is, they're not, but mainstream publishers don't care what we like to read, they concentrate more on what they feel they can sell. Hence many of the authors who write in these genres, the midlist authors of old, are vanishing from bookstore shelves around the world. Some of these authors have reappeared online, in electronic format. (Years ago, Brian Aldiss spoke to me about bringing out his entire 200 plus story backlist as ebooks and was in the process of doing so. I haven't seen them yet, so I assume the deal went sour, however, I recently purchased the ebook version of The Eternity Brigade by Stephen Goldin, one of my all time favorite books, which is out of "print", but not out of "e-print". I was ecstatic to find it still kicking around. But I digress.)

The trick is this. Once a book becomes more involved, such as when an author introduces politics or real character development, it tends to move out of that lowest common denominator and into another subgenre with more "substance".

Time travel books might be considered another subgenre of SF. So might sociological science fiction, which tries to predict what society and politics will be like in the future. In sociological science fiction, the technology is less important and the way people live is more important. Examples of sociological SF would be Ben Bova's excellent book Millennium and Isaac Asimov's SF classic, The Foundation Trilogy.

To give you an example of a fantasy subgenre, try modern fantasy, in which a fantasy element is introduced into today's world. As an example, the movie The Indian in the Cupboard will do, along with many episodes of the television series, The Twilight Zone. In one of my favorite episodes, Walking Distance, Martin Sloane walks back in time to visit the home town of his youth and learns a very valuable lesson.

There's also historical fantasy. I've recently read Sailing to Sarantium by Guy Gavrial Kay, which takes place in the Roman Empire, though it clearly contains fantasy elements. If you like your books grounded in history, with a lot of detail, you'd probably enjoy this one. I know I did.

Another speculative fiction genre I enjoy is alternate history. This is where an author looks at history, changes one event and tries to guess what the world would be like if things had been different. Alternate history is usually more closely related to science fiction than fantasy, though in at least one case I can recall (Too Many Magicians by Randall Garrett), the reverse was true. My example of this genre, since I've already mentioned it, is Too Many Magicians, which was also a locked room murder mystery that happened to take place at a wizard's convention. You could hardly find a better example of a cross-genre piece (a fantasy/mystery/alternate history novel).

Here is a brief listing of spec-fic subgenres. I've included horror subgenres as well, even though I'm more familiar with fantasy and sci-fi. Hopefully, I've read enough horror to get at least some of it right. So without further ado, The Speculative-Fiction-Not-So-Neat-Little-Boxes Chart. Keep in mind, I am in no way attempting to create a comprehensive listing. For one thing, I'm not completely insane (just mostly) and for another, the debate rages so strongly, it would be impossible to even start such a project without running into problems that breed faster than tribbles.

Speculative Fiction

Science Fiction

Space Opera

- see above

Sociological SF

- see above

Cyber Punk

- Dark, near-future, technologically-dominated society (think Neuromancer by William Gibson for books or Bladerunner for movies)

"Hard" SF

- where the actual science is as or more important than plot or characters. This is probably the most highly respected subgenre by fans (Most of Larry Niven's solo work as well as almost anything by Arthur C. Clarke falls into this category).

Time Travel

- self-explanatory (Do I really need to say The Time Machine?)

Utopian

- The perfect future society, which of course has problems, or there wouldn't be a book (Think Logan's Run)

Dystopian

- The worst future society imaginable (think Mad Max or Water World)

Romantic SF

- A relatively new subgenre (as these things go), romance drives the plot of the book, rather than any sci-fi device (As was the case in Shadow Crossing by Catherine Spangler)

Alternate History

- At some point history follows an alternate route when a pivotal event occurs differently. The ultimate "What-If?"

Humorous

- Douglas Adams (enough said)

Fantasy

Swords and Sorcery

- see above

High Fantasy

- usually dealing with Kings, Knights and that ilk. Also called Heroic fantasy (think A Game of Thrones by George RR Martin)

Epic Fantasy

- closely related to High Fantasy with LOTS of crossover. To be an Epic, you need a long, intricate story (think Lord of the Rings or Robert Jordan's Wheel of Time series).

Modern Fantasy

- see above

Magical Realism

- Stories in a contemporary setting, which include a hidden magical world which the author tries to make as plausible as possible. Perhaps plausible is the wrong word. By making magic an accepted part of the backdrop of the book, the magical element seems more plausible. In general, these books are "supposed to" have a more literary style. (I'm currently reading the book Little, Big by John Crowley, a perfect example of magical realism, down to an amazing use of the English language.)

Paranormal

- ESP, ghosts, vampires, even werewolves (to give you some idea, my short story Tales from Beyond--which you really should get over to my web site and read--is a perfect example. Just look in the fiction section.)

Historical

- see above

Mythologic fantasy

- any fantasy based upon mythologies, whether it be Roman, Greek, Norse, Celtic, Native American, or what have you (think Arthurian Legend, or the Mabinogian books by Evangeline Walton)

Romantic fantasy

- yes it's invaded fantasy too! (Stephen Donaldson's Mordant's Need series comes very close.)

Humorous

- Terry Pratchett (enough said)

Horror

Psychological

- horror that teases the mind into fear, rather than presenting you with a "monster" image. (As an example you might consider the movie, Mr. Frost with Jeff Goldblum, chilling with its implications more than anything shown. I'd even place The Shining by Stephen King, into this subgenre)

Splatter Punk

- Gore, gore and more gore. My least favorite of all spec-fic subgenres (I'd love to provide an example, but I don't read it, so I can't.)

Gothic Horror

- any horror with a gothic feel to it (think of all those old spend the night in the haunted mansion stories)

Modern Horror

- same as modern fantasy, but designed to scare the pants off you

Historical

- using the past as a setting to scare the pants off you

Mythological Horror

- I don't even know if this is a recognized subgenre, but if it isn't it should be. There's plenty of it out there. Anything that deals with mythology, etc. that scares the pants of you

Humorous Horror

- as with the other major genres in spec-fic, horror has been combined with humor, sometimes successfully. Most horror humor uses the trappings of horror, but is funny rather than scary.

I could probably go on, but I'm not going to. I think you get the idea. If you don't, you won't be alone. Genre is such a subjective issue, it confuses even those of us who think we know what we're talking about.

One final warning. If you happen to be at a sci-fi convention or you belong to an online list, be very careful what you say about genre unless you're ready to defend your position to the death. There is little that can get a sci-fi fan annoyed more quickly.