I'm blogging about this because its directly relevant to my current project. I was procrastinating on my NaNoWriMo outline because... well I love to procrastinate! And I ended up brainstorming ideas for my epic fantasy, anything from how many moons to have, to the full extent of the magic in my world.
It's always important to set boundaries, no matter what kind of fiction you're writing, but especially when the supernatural is involved. There's nothing worse than a character only able to do one or two things, and then at the end they miraculously solve the big problem with a burst of magic you never knew they even had, especially if it would have helped earlier as well. It seems fake, well, because it is fake. Most of the time that happens when someone needs a resolution and can't dig themselves out of the hole they created. Believe me, I've done it, and its bad. Resist. Resist I say!
To avoid it, I'm starting at the very beginning, thinking of all I need to accomplish in the story and setting the parameters of what's possible and impossible in that world.
For example: My elves
Some use magic to manipulate the elements, but in a very small way. Ex/ They can't start things on fire, but they can create a bigger fire from a spark, small flame, etc.
Have startling grace
Create light orbs with their palms (theses are light elves after all)
Have pointed ears and small frames, though most are rather tall
Possess more strength than you would think
Have really bright eyes
Have a way with animals
Heal with touch
Live quite a bit longer than humans (due to the fact that they can just get another elf to heal them if they get old and ill.) Their only natural cause of death is old age.
Contain unlimited magic
Walk on water
Run any faster than the average person
Worship dark magic (that's for the dark elves)
Heal without consequence
Stand up against man made weapons and live to tell the tale (they're not invincible)
Jump tall buildings with a single bound
Don red and white outfits and make toys
Live in trees and cause woodland mischief, or anything else equally ridiculous.
In summary, they're just taller, prettier, more graceful people with the ability to push the wind in a different direction for a minute, or make a light orb with their hands to defend themselves.
What boundaries have you set for your characters? For your world?