You’re very talented at taking seemingly mundane or unusual things and creating magic systems around them, like color in Warbreaker, metals in Mistborn, and light in The Way of Kings. Can you explain how you decide what to use for a magical system in a book, and your process for building a coherent system once the initial concept has been decided?
First of all, I’m looking for something that fits the book that I’m writing. So for instance, in Mistborn, I was looking for powers that would enhance what thieves could do. I was also looking for something that had one foot in alchemy, in that kind of “coming-of-age magic into science” way. Alchemy is a great example because it’s a blend of science and magic… well, really, a blend of science and superstition, because the magic part doesn’t work. So something resonates there.
I’m also looking for interesting ways to ground [the magic] in our world, and using something mundane is a great way to do that. Magic is naturally fantastical, and so if I can instead use something normal, and then make it fantastical, it immediately creates a sort of… ease of understanding. Burning metals sounds so weird, but it was chosen for that same reason, because we gain a lot of our energy through metabolism. We eat something, we turn the sugars into energy, boom. So that’s actually a very natural feeling. When I started writing out some sample things, it felt surprisingly natural, that people eat metal and gain powers, even though it sounds so weird. It’s because of this kind of natural biology. So I’m looking for that.
Once I have a magic system, I look for really great limitations. Limitations really make a magic system work better. Wheel of Time is a great example. Having a magic system where you can weave all these threads is awesome. Having a magic system where you do that, and then it drives you mad, is even better. It creates plot hooks, it creates drama, it creates challenge. [That limitation] is brilliant, I think it is one of the most brilliant ever made, especially because it also changes your characters. It has a deep influence on your character arcs, so you can tie it into character.
Beyond that (and this is kind of pulling back the curtain a little bit), there is no specific defined place where someone goes mad, so you can actually stretch it out and use it when you need it. It doesn’t constrain you too much. Like if your magic system’s limitation is, “When you use this magic, you have to use the head of one of your grandparents.” (laughs) You can use that magic four times! It’s limited, but also very constrained. Going mad is not as constrained. There’s a spectrum there - you can use it when you need it. So I’m looking for cool limitations that will work that way, in ways that I can use to force the characters to be creative. A good limitation will force you to be creative, and your characters to be creative. Pushing and pulling metals is basically telekinesis, right? But by making it center of mass, you can only pull directly towards yourself or push directly away from yourself... Number one: it’s vector science. It has one foot in sciences. Number two: it feels very natural to us because this is how we manipulate force ourselves. Number three: it limits things so much that it forces creativity upon the characters. There’s that sweet spot, where they can be creative and do cool things, where it doesn’t become too limited, but it also keeps you from having too much power in the hands of the characters, so they are still being challenged. I’m looking for all that, and on top of that I want to have good sensory ways to use magic.
I don’t want to have two wizards staring at each other, and then be like “and they stared at each other very deeply! And then they stared harder!” I don’t want it all to be internal, which is where the lines for the metals came from. You see something, you push it forward. The pulses that some of the allomancers use, they’ll hear. I wanted sensory applications.