Social Magic in RPG

I have had a long running issue with the power of magic in D&Desque role-playing games. They allow too much power without any corresponding responsibility – no society could possibly survive in such a situation. It would only take one disaffected 20th level magician to destroy 1000 years of progress.

Runequest had a more realistic system, where powerful magic was utterly embedded in the system, so you had to be part of the social structure in order to gain access to it. The problem was that it lacked the pzzazz of the D&D system.

What I am looking for is something in the middle, and today’s idea is this. Many systems have the idea that metal or encumbrance interfere with magic, to reinforce the standard trope of the unarmoured mage.

What would happen if people interfered with magic as well. The more intelligence there is in the area, the more difficult it is to cast spells. You need to open yourself up to the flow of power to cast spells and people make that more difficult.

The advantage of this is that you can still cast the powerful fireball down a dungeon where no one is around, but you can’t cast it so easily in a village and it is very, very difficult in a great metropolis. A self-levelling system? I think I need to think through the ramifications of it, but it could be a nice little idea.