Do you have anything specific in mind? Medival realistic, sci-fi, fantasy or anything else? And if you're familiar with the tier system, then it would be great to have some fixed power level.
Tried jumping into the seat of a motorcycle from the 4-th story like some comicbook badass and died from excruciating pain that led to a heart attack when you were successful in doing so. Try and guess why it was so painful.
BTW, maybe we could include sych a thing as a mutation chance? Some would result in negative effects, such as leukemia, or positive ones, such as myostasin related muscle hypertrophy.