Nothing kills a story faster than a flimsy conflict, and in a universe where magic exists, the biggest mistake a writer can fall into is to make magic too easy. It seems paradoxical: after all, the whole point of magic is that it makes the impossible possible, but if magic solves every problem with little or no cost, the story loses its emotional significance. Like all things, magic must have limits, and those limits must be clear and identifiable.
I have become deeply frustrated with a favorite series of mine recently for precisely this reason. R.A. Salvatore’s The Legend of Drizzt is a high fantasy series following in the footsteps of The Lord of the Rings, but incorporating elements of the popular Dungeons & Dragons tabletop game. The first book of the series was originally published in 1988 and the series is ongoing, with more than twenty novels and a dizzying number of spinoffs. The main character, Drizzt, does not use magic all that much, so the very fuzzy and ill-defined limits of magic in this universe started off as a non-issue. Typically, a powerful magical antagonist would appear and Drizzt and his pals would have to defeat the baddie with the power of cleverness and friendship and whatnot. Also, swords.
As the series went on, however, main characters gained magical items, sympathetic magic-users joined the party, and problems started.
Magic became a flexible and convenient way to get characters out of any situation (unless, of course, inability to get out of the situation was plot-convenient). As an example: during one book, Drizzt is captured and tortured for weeks. Immediately after being rescued, the party conveniently comes upon some healing potions and Drizzt was fighting fit and emotionally stable in moments. In a later book, Drizzt’s wife Catti-Brie is mortally wounded. She survives long enough for a tearful, manpain-inspiring farewell, but of course, even though there was a battle going on and magic-users in the immediate vicinity, it seems nobody had thought to bring a healing potion. Or maybe healing potions don’t work on ladies, as a lot of them seem to die for no real reason.
It has become rather difficult for me to take even my favorite character—Jarlaxle—seriously. He has such an absurd array of magical fix-all items, that his absurd array of magical fix-all items has become an in-universe joke. His hat is an extra-dimensional pocket in which he stores literally everything on the planet, from clean underwear to objects that make him impervious to magic. He keeps a magical horse in there. An actual horse. At the beginning of the series, Jarlaxle and his mercenary band were living in relative secrecy under a matriarchal dictatorship, so Jarlaxle’s conflict was largely political and emotional, but now that he has left that environment he does very little besides gleefully irritate people, have a lot of sex, and generally face no consequences.
Failing to limit magic has both logical and emotional consequences, and as a student of economics, I struggle with the logical as much as the emotional. As with any commodity, if magic is abundant and freely available to everyone, it becomes worthless. In the Legend of Drizzt series, even people who are not sorcerers often use magical items with little or no effort (again, unless it is plot-convenient that the item require effort). Someone could get a magical charm to protect their house from burglary, but if a burglar can easily acquire an invisibility spell that can trick it, why would anyone bother? Furthermore, if magical artifacts are available to good guys, they are easily available to bad guys. Theoretically, any advantage gained from magic should be null, because everyone else of similar means has easy access to it.
In my experience, the best way to present magic in fantasy is to make it function as alternate universe physics. If you loved Fullmetal Alchemist as much as I did, the Law of Equivalent Exchange is probably more ingrained in your head than anything you ever learned in science class. Don’t mourn your lost education; the Law of Equivalent Exchange is just another way of describing what is arguably the most important scientific law in the universe: the Law of Conservation of Matter. In the Fullmetal Alchemist universe, magic functions on effectively the same principles as reality: nothing can be created or destroyed; in order to gain something, you have to give something up.
When magic is valuable and difficult, the hero can win because they are willing to sacrifice more, or because they have more friends willing to help them. Alternatively, the bad guy can rise to power because he has more money or resources, or he inspires more fear. The random, meaningless arms race of who managed to find the most powerful magical artifact in a dirty cave this week does not become the only conflict. If a character can be easily healed, the reader never truly feels that they are in danger, but if a character can only be healed by someone else giving up years off their life, the emotional ramifications are massive.
I will probably keep reading The Legend of Drizzt series until I die (or until the author does, which is likely to be sooner) even though I know it’s far too late to retroactively limit magic enough to force the magical economy to make sense. What I hope for now is that—as the cycle of overpowered characters and artifacts spirals out of control—the main characters will find that they have effectively become deities and will have to face the larger problems that this creates. Knowing Mr. Salvatore, the solution will likely involve lots of sword fights and some very manly emotional repression.