For Mistborn, I came to the book wanting several things. I wanted a great magic system that would enhance the graceful, martial-arts style fights. This was going to be a series of sneaking thieves, assassins, and night-time exploration. And so I developed the powers with a focus on that idea. What would make the thieving crew better at what they did? I based each power around an archetype of a thieving crew. The Thug, the Sneak, the Fast-talker, etc.
At the same time, I wanted to enhance the ‘industrial revolution’ feel of the novels through the magic system. I wanted something that felt like an industrial-age science, something that was a good hybrid of science and magic. I found myself drawn to Alchemy and its use of metals, then extrapolated from that to a way to release power locked inside of metal. Metabolism grew out of that. It felt natural. We metabolize food for energy; letting Allomancers metabolize metal had just the right blend of science and magic.
How did you choose the specific powers?
I made a crew and thought, “What powers would make them better?”
How did you come up with the idea of three separate powers in one world? I’d especially like to know how the idea of hammering spikes into a living person could come about.
Allomancy and Feruchemy were originally planned separately. I linked them together into this book when I realized that the ‘focus’ items that could store attributes could be metal, and therefore work wonderfully with the Mistborn book I was planning.
Hemalurgy came from the image of Inquisitors first, then developed as a need to integrate it in with the other two in a way that evoked the power of “Ruin” rather than the power of Preservation. I figured that Ruin would steal, and it was a great way to add a third magic without having to overload people with a whole new set of powers. The process of writing this series, since I did all three books together, was an interesting one, and I made a lot of connections as I went. Some of the latest things on the timeline were figuring out how to fit atium and the Preservation nuggets into the already built framework.