I’m currently working on pre-writing my next book, and one of the aspects of worldbuilding that I’ve struggled to pin down is the magic system. I’ve been looking to create a system that is transient, where the rules change in predictable but complex patterns. The part that’s given me the most trouble is figuring out the exact limitations and costs, which change based on time and place.
I’m a big fan of Brandon Sanderson, the master of magic systems. His second law of magic states that limitations are more interesting than the powers, but when he says limitations, he really means limitations and costs. I believe this is true, and so as I’ve worked on designing my system, I’ve spent a great deal thinking about these two aspects.
Eventually, I got to the point that not only did I think the system was too complex (which I think it still might be), I also thought I was strangling the characters. I set up a significant set of limitations, then plunged ahead and created a slew of fairly dire costs. Then I realized that my characters were never going to be able to use the damn magic I gave them.
What I think I’ve come to realize here is that most good magic systems will be designed with a trade-off between costs and limitations. Not an uncertainty principle exactly, but analogous in a way. The greater the limitations, the lesser the costs should be, and vice versa. Too light on both and the magic is generic and the characters don’t have to struggle much, too heavy on both and they never get to use the magic. Which sucks. Stories with no magic are boring (60% of the time this is true all of the time).
So I’ve decided to go with a system that is heavy on the limitations, but lighter on the costs. Not that it lacks costs, of course, but they aren’t so dire that no one has to sell her soul just to jump a littler higher.