About 35 years ago, when I was in high school and just beginning to think about writing seriously, I remember reading an article in Starlog magazine. It may have been written by David Gerrold, who had several columns in Starlog over the years. But the piece I remember talked about the difference between science fiction and fantasy. The author pointed out that science fiction had rules – that was the “science” part – whether the story involved science or technology or whatever. In science fiction, if a character can read minds or levitate objects, there must be rules about how that skill can and can’t be used, its limitations, etc. Whereas in fantasy, you can say the character can simply blink his left eye and levitate something. Fantasy needn’t have rules.
Immediately this bothered me. Oh, I saw the truth of it in the stories I read at the time. On one hand I had Larry Niven and Robert Heinlein with their hard science fiction that always made sense and was always internally consistent. And on the other hand I had Piers Anthony with his pun-filled Xanth books where nothing was sacred and anything seemed to be possible because of wild magic. I saw something then that I have always held onto in my writing (and reading), and that is that fantasy aught to have rules, too. After all, magic is really nothing but science we don’t yet understand. Science we understand perfectly will appear as magic to someone who does not understand it.
So I set out to write my Great American Overlong Fantasy Epic with this radical idea in the front of my mind: the magic has to make sense, it has to be internally consistent. I would treat it like science as if I was writing a science fiction novel.
Years later I began to realize that I was not the only person to do this, and if you listen to any successful fantasy writer or writing instructor today, they will tell you that your magic system must make logical sense, be internally consistent and have clear limitations and consequences. Many people still equate sci-fi with space ships and ray guns, and fantasy with dragons and wizards, ad leave it at that. But, in fact, Star Wars is pure fantasy. It’s like the Xanth books; there is no attempt to define or quantify “the Force” and the technology – while it looks fantastic – is based on no science anywhere. A planet that is a ball filled with water, where you can pilot a submarine from one side to the other by going through the middle? Giant tanks that walk on four legs? A spherical space station the size of a small moon? Whereas books like The Dresdon Files, a series about a wizard who lives in present day Chicago, are more like science fiction than fantasy, because Harry Dresdon’s magic is tightly defined, internally consistent, and its limitations are an integral part of the character and plot. Harry’s magic is as much science fiction as the transporters on Star Trek. Neither happens to exist, but if you accept that they do in their respective universes, they are both utterly reliable (or predictably unreliable) every time.
I am involved in a summer critique group for authors with finished manuscripts. One of those manuscripts is a middle grade of great promise that happens to deal with several kinds of magic. However, in reviewing it I found that I was vexed by the complete lack of differentiation between the different kinds of magic. One was witchcraft, another was priest-based magic, and the third was wizard-type magic. But in practice, they all worked exactly the same. In my view, if a character casts a spell, the reader should instantly be able to tell what kind of magic it is. The thing that really put the nail in the coffin for me was the priests were accusing a main character of using witchcraft, when that character was actually a wizard (and being accused of witchcraft was apparently a great insult). But the wizard in question was actually using priest-based spells against the priests! And the priests still thought they were dealing with a witch.
Audiences are much more sophisticated now than they were 35 years ago. Because authors and filmmakers have realized that any skill set – magic, technology, super-powers – must be defined, have limitations and remain consistent. And if there are more than one in a given story, they must be distinct. In The Avengers, we have four super-strong heroes: Iron Man, Captain America, Thor and the Hulk. But their super strength is different in every case, and each has their own limitations. Thor is an alien, whose race is generally stronger than humans, while Iron Man wears a suit invented by Tony Stark. Both Captain America and the Hulk are strong because of gamma radiation (under very different circumstances), but the Hulks strength is Bruce Banner’s weakness, and the Hulk is a beast with little or no control. And Captain America is a man out of his time with strong values which severely limits what he is willing or capable of doing. Of all of these strong men, only Thor can lift Thor’s hammer.
All four of these men have very distinct kinds of physical strength, which are used in different ways under different circumstances. The book I mentioned above is more like a superhero movie with three Supermen, each wearing a different colored cape.
So if you are writing speculative fiction, and your story contains some special skill or technology, it will pay to make it believable. I don’t mean possible. Science fiction has never been limited by the possible. Only the believable. Faster-than-light travel is not possible. But it is readily accepted in science fiction as long as it is treated like an existing science. In today’s market, magic is the same way. Even for children. Because the competition is fierce and readers of all ages are less forgiving than ever.