After reading Mistborn: The Final Empire I have created a model of worldbuilding for fantasy novels. Within this model, the creation of a setting's magic can be summed up as either subtractive or additive. They probably each have their merits, but I've also come to realize that I far prefer additive magic.
It works like this. For subtractive magic world building, assume that magic exists and can do anything. Then, begin making subtractions and limitations. This kind of magic is hard to do, that kind of magic requires a costly sacrifice, only this nation knows how to do the other kind, and a this and that are impossible, and so on. If you keep it up long enough, you eventually have a pretty good magic system for your setting, full of (carefully limited) possibility. Some books and games that seem to have used this method include the White Wolf canon, especially Mage (both iterations), and, well, most every fantasy novel ever written.
For example, in Steven Brust's Dragaera, you can return the dead to full and normal life, but it's pricey, only has a one-in-three chance of working, and doesn't work if the corpse is more than three days dead. Other kinds of magic are similar: you can basically do whatever you want, but some things are harder than others.
Unsurprisingly, additive magic is the opposite: instead, you start with the assumption that magic doesn't do anything - that it doesn't exist - and add capabilities one at a time. Examples of this approach are fewer and further between than the more popular subtractive approach.
I'm willing to grant that the subtractive approach has its strengths. It's much easier to create a sense of infinite possibilities if the possibilities really are (nearly) infinite. If you want magic to seem a vast and incomprehensible mystery that your characters will only scratch the surface of, subtractive magic is the way to go.
However, the additive approach has several notable strengths as well: it tends to produce magic systems that are tighter, more easily understood, and easier to handle narratively. Most importantly, additive magic is often more thematic than subtractive magic because the entire system can more easily be designed with a single thought in mind.
Case in point: Sanderson's magic in the Mistborn trilogy. There are two competing forms of magic: Allomancy and Feruchemy, each of them well defined and (I imagine, anyway) best described through the additive approach. Both kinds of magic are dependent upon metal (Allomancers swallow it, Feruchemists wear it) which adds scarcity-driven tension to the novels' general grittiness; if an Allomancer runs out of metals or someone makes off with a Feruchemist's metal bracelets, the magician is out of luck. Both forms of magic are dependent upon which metals the magician uses, which provides a nifty pacing guide. As the story progresses and the characters learn more about their world, they discover more metals and use them to do things they thought were impossible before. In the end, however, there are only so many metals, and so many capabilities the characters can tap.
Finally - and now I'm speaking from Sanderson's own notes to the series rather than pulling stuff out of my butt - because most Allomancers can only use one metal, the initial group of characters are easily brought together because of their disparate specialties. In addition to being an interesting way of tying characters of vastly (and hilariously) different personalities into the same story, it also adds to the "magical heist film" feel Sanderson was going for. Like the international criminals of Ocean's 11 or The Italian Job, each of Sanderson's thieves has their own specialty, and only by working together can they achieve their goals.
A brief disclaimer: I have no idea how Sanderson actually writes. If he deigns to visit my humble zeppelin, I'd be tickled pink. If he actually comments and lets me know, I'd probably be tickled purple. You know, deeper than pink.
Right, then. Anyhow... let's bring it all home: how have I interacted with this model of world building?
I'm sad to say that until now I have mostly used the subtractive method out of sheer habit, even in some stories which - in retrospect - might have benefited from the additive method. For example, in Knights of the Land (the current working title of the rewrite of what was once A Knight of the Land - more on that in a later post) all magic involves tapping into the living earth. Some people, like the titular Knights, do it organically as part of their role as the land's protectors, while other forces, like the Mountain-Killing Crown, rip power out of the earth in a way that's bad for everyone. However, despite the fact that all magic has a unified source, I haven't done much to give all magic a unified feel. Knights can use the power of the land to enhance their bodies, heal, and divine. Land-draining machines can unnaturally extend your life, make you invulnerable, throw fire at people, make your fields fertile (at the expense of your neighbors') and blow up mountains... and that's just the relics I mention in the novel. There's no indication that the relics are limited. I have to do some serious digging and decide if I want to apply my new insight... or let sleeping novels lie. On the one hand, it's a pretty big change to make so late in the process, but on the other hand, I am in the middle of a rewrite...
However, I have been fascinated by the additive approach for longer than I've given it a name. I've mostly expressed this through RPG.net "Setting Riff" posts, but now I'm wondering if I shouldn't go back through some of those posts and see which might have story potential. The one where I flip our society's ideas of "male" and "female" magic to create a world where only men can heal and divine and only women can throw fireballs and such is probably still a branch of subtractive magic, since I'm still limiting infinity, but what about the world where all magic is illusion? That might, as they say, have legs...
Anyway, I recommend that you all check out Sanderson's Mistborn trilogy, because they're awesome, and that way you'll have more comments to make when I finally do get around to posting a review. And you should all also think about the possibilities of additive and subtractive approaches to magic. I'll post some food for thought below.
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- Where have you read what you now think was probably subtractive magic? This will likely be a long list.
- Where else have you read what you now think was probably additive magic?
- What do you think I should do with Knights of the Land?