It occurred to me this month that I've given short shrift to a whole genre of fiction. In the past I've written columns on writing horror and science-fiction, but never one on fantasy. Indeed, in one of my columns I went far out of my way to praise the virtues of SF over fantasy. And yet, the bulk of my own work has been... Fantasy! So, let me wipe a little bit of egg off of my face and then we shall begin.
Fantasy is perhaps the largest and hardest-to-define genre in all of fiction. It encompasses everything from many of the episodes in Homer's Odyssey to, according to some purists who refuse to categorize it with SF, the Star Wars epics. While I've yet to come across a decent 'official' working definition of fantasy, in my own mind I've always defined it as any work that includes a 'fantastic' or 'unreal' element which consists of anything other then a logical development of current science. As a concrete example of what I mean, consider a story which involves humans changing into frogs. If it happens because a fairy princess waved her wand, the story is fantasy; if the transformation is the result of massive advancements in biological science, it's science fiction; and if some hideous, polysyllabic, demonically unpronounceable Thing inflicts that change on an unwilling, screaming victim, it's horror. While most horror stories are indeed fantasies and require precisely the same writing skills, in practice there is a fairly clear dividing line between the two genres. Almost all folklore can be described as fantasy, as can any 'magical' story.
It's only in my own lifetime that fantasy as a genre has become respectable for anything but children's stories. During my early years, bookstores devoted only eight or ten feet of running shelf-space to science fiction and fantasy combined. Even this tiny area, however, was unfairly divided. Usually, there was something like seven-and-a-half feet of SF, and several copies of the Lord of the Rings, which then comprised the total sum of mass-marketed English-language fantasy that existed in the entire world. There were no other fantasy books available to Joe Everyman; once he finished those four books, there was nothing else available anyplace, or at least not in my neck of the woods. Not even in the libraries! I recall well my own disappointment when, at about age fourteen, I finished The Return of the King and had nowhere, literally nowhere, else to turn for more. So much has changed since then for the fantasy reader, and all of it for the better! Today, there is far more fantasy being written and sold than SF. It has penetrated our society at every level, so that even mass-marketed TV programming abounds in fantasy-derived plotlines. Our world is much the richer as a result.
I've always believed that writing, like most art, is more about emotion than anything else. This is even more the case than usual with fantasy. An SF writer can impress a reader with the sheer intellectual scope of his concepts and ideas, and horror-story authors can always lean on the gross-out factor. But fantasy writers have to work without a net, so to speak. Today's readers are so jaded that it's very hard to enthrall them with the idea of, say, a man turned into a dog or perhaps rendered able to fly via magical means. All the easy ideas have been used over and over again, so that in order for a story to carry impact it simply must be sound in terms of basics like characterization, plot, narrative hook, and action, action, action. In this sense, fantasy is perhaps the most demanding genre of all; nothing falls flatter than magic badly written.
Which brings us right back to what makes fantasy fantastic: Magic, or some other unreal mystical force. In the end, when writing fantasy an author simply cannot help but deal with the issue of mysterious forces and the suspension of disbelief. I've seen various approaches taken towards this issue; some authors stick strictly to existing mythological structures, attributing everything to Seely and Unseely Faeries and the like. Others work out incredibly detailed magical systems with strict rules and limits laid out clearly for the reader. Me, I've always considered that one of Stephen King's most admirable talents as a writer is the way he can draw a reader so deeply into what begins as a totally mundane story that when fantastic things start to happen, no one even thinks to question them at all. He never explains his magic-systems in detail, nor where the demons ultimately come from. Yet his best works practically pulsate with the power of the fantastic elements that drive them, and his magic-makers leave tracks so deep in his readers' minds that many suffer from nightmares for months thereafter. Personally, I've made a conscious decision to try to emulate King's success in my own works by trying to initially frame the fantastic elements in a setting so emotionally loaded that the reader, caught up in the 'mundane' aspects of the story, really isn't in much of a mood to ask silly questions when my character casts a spell or shapeshifts into something else. It helps, I think, that both King and I tend to write in familiar, modern settings that the reader can easily immerse themselves in; I don't know if this approach could work for a fantasy set in, say, fourteenth-century China.
Another thing I consciously attempt in my work is to use a point-of-view character that is never in the least surprised to encounter magic or the fantastic. If the POV character is totally credulous when seeing his friend turned into a frog, then it is more likely that the reader will be credulous as well. While a lot of fantasy stories have been written in which the POV character is not anticipating an encounter with the fantastic, I frankly have never liked writing them. It's much harder to maintain a willing suspension of disbelief in such a tale, I think, and the longer the tale is the more true this becomes. On the other hand, other authors clearly more gifted than myself have done well with the 'shocked protagonist' approach.
I also try not to offer any more information about the nature of magic than I really need to, again in conscious emulation of King. There is no single large reason for this, but rather many small ones. One of these is that in general most such explanations take the form of exposition, the least-entertaining and emotion-engaging and therefore least-desirable of all story elements. Even when such explanations are successfully placed in plot-context, however, as a rule they tend to be dull space-fillers that neither advance the plot nor develop the characters. Far better, in my book, that things just are, that magic simply is, and that the shamans/priests/fair-folk can do what they can do because that, quite simply, is just the way things are.
This isn't to say that magic doesn't need rules -- far from it! Indeed, virtually any kind of fantastic element in virtually any kind of story requires the very strictest of regulation, lest the whole thing descend into a molten, meaningless glob of power-gaming. King's Wendigo in Pet Sematary, for example, had a very strictly limited kind of power. In my own Corpus Lupus'', the only way to get magic to work is to torture someone to death. In the best of all possible fantasy books, the limiting rules are also key plot-drivers; in Corpus'', since magic could only be derived from human sacrifice, I told my tale from the point of view of a homicide detective. I also capitalized upon my self-imposed restrictions further by hypothesizing that if magic was possible, then governments simply had to have a way of legally employing it, if for no other purpose than to combat illegal magic-users. This implied the existence of the Guild of Necromancers, which in turn caused me to consider the psychological and moral effects of being both legally empowered and professionally expected to torture dozens of innocents to death and then ritually mutilate the resulting corpses over the course of a career, and...
...well, read the book if you'd like. Suffice it to say that I ended up very proud of the uses I put my magic-limiting restrictions to.
Another thing to consider when introducing a fantastic element is how its existence will alter the world outside the immediate plotline of your tale. If you're doing an unexpected encounter in the mundane world, where magic is normally hidden away, then you will not encounter this problem. Everything will remain just as it is, because no one else besides your protagonist and other characters knows the real truth of things. If, on the other hand, you wish to write of a world where wizards operate out of storefronts and magic classes are taught on every streetcorner, then you also have to ask yourself how else this world might be different. For example, could mages also act as doctors, enchanting failing hearts and teleporting crystal-ball-detected gallstones out of pain-wracked bodies? If flying carpets are possible, what happens to the market for horses? Could knights fight effectively from carpet-back? If so, what might their fighting-equipment look like? What sort of saddle might they employ? Clearly, the primary problem is that magic is so damned useful that, if it existed in unlimited quantities, it would be applied to virtually every human problem from sewage treatment to erectile dysfunction to crappy network TV. Larry Niven dealt with this most brilliantly in his two novel-length fantasies The Magic Goes Away and The Magic May Return. (These two works are in my opinion required reading for any budding writer of fantasy.) Those of us less talented than Niven, such as myself, are far better served by a) finding a way to strictly limit the amount of magical power available to society and b) tossing the reader a few bones during the telling of a tale that show how the existence of magic has changed the way of things; in one work, for example, I mention in passing that the President has a spell-corrected heart defect, while in another there is an Internet support-group (complete with chatroom) for those Cursed to undergo involuntary transformation into other forms.
In the end, as stated earlier, the single most important factor in producing an excellent work of fantasy is emotional connection with the reader via characterization, setting, plot, and all the other basics. While handling the fantastic element properly is important, nothing can save a story that is weak on the basics. Like SF and most horror, fantasy involves a truly massive willing suspension of disbelief on the part of the reader.
Build a good foundation, and the rest will follow along just fine.