The Elder Scrolls: Fate of Tamriel
From p. 32 of Fate Core
Your high concept is a phrase that sums up what your character is about – who he is and what he does. It’s an aspect, one of the first and most important ones for your character.
Think of this aspect like your job, your role in life, or your calling – it’s what you’re good at, but it’s also a duty you have to deal with, and it’s constantly filled with problems of its own. That is to say, it comes with some good and some bad.