William Ronald said:To me, the term munchkin implies power that is not earned. I have seen characters who did not earn their power who were only 10th level (with weapons which were weaker versions of stuff from 1st Edition Deities and Demigods) to people who had weapons out of the cartoon show Thundarr the Barbarian (and took the sunsword directly from the sun.) It was not the power that offended me, but the fact that it seemed to be just given away.
I agree with this - munchkinism is not about power, but unearned power - EGG's discussion of Monty Haul campaigns in the 1e DMG gives a good analysis. U_K/Craig has slight munchkin tendencies I guess (at this time I can't recall very well, but I seem to remember that a few of Thrin's levels might have been gained in 'solo' play when I was burnt-out - U-K can confirm/deny) - but as a DM I've never had any trouble terrorising him with foes more powrful than Thrin - Hel, Wotan, Doomstar (not actually a foe), Arasaka ACPA troopers, etc. I'm generally considered a tough GM, even a killer GM by some. And certainly 90%+ of Thrin's levels were earned in games I GM'd.