To quote Lewis Carroll, "But I was thinking of a plan/To dye one's whiskers green/And always use so large a fan/That they could not be seen."
Originally Posted by templeorder
Or, less obscurely, instead of creating world-shaking magic and then gimping it at every turn, use a magic system that is inherently low-powered (e.g. RuneQuest in all of its incarnations), inaccessible (e.g. Pendragon), or morally reprehensible (e.g. Sorcerer and the "Carcosa" supplement for OD&D).
"On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."
- Charles Babbage (1791 - 1871)