<i>Disclaimer: I'm not trying to come off as a jerk. Really. Trying to tie any numerical system to intellect is difficult if not impossible (even Binet thought, at the end, that his IQ test was crap), but DnD is an abstraction, and it can be done with some forethought. I try my best not to be arrogant about intelligence, for two reasons: being intelligent has made my social life hell at times, back when I was fourteen and still arrogant about it; and I've had my ego blasted enough times to have gladly spent the GP for a wish spell for an inherent -5 penalty to INT. Unfortunately, I live in the real world.
However, as some would dispute any claim of 18 or greater, I feel I must defend.</i>
I think you may be overestimating a little (or a lot). Are you looking at a bell curve of D&D heroes, Gamers or just average people? AFAIK, a 14 INT qualifies you as a Genius (as one point of INT equals ten points of IQ, or so I'm told), So that gives you an IQ of 190, which is pretty damn high, puts you level with Issac Newton, and makes you one of the smartest people on the planet. Now I've no doubt that you are highly intelligent (warranting at least a 14), but are you really THAT intelligent?
EDIT: I've been chacking around, 19 INT would put you in the top 0.0000001% (aproximately) of the Population...
To get a sense of INT distribution, I used a standard bell-curve (normal) distribution based on 3d6 (which gives a number between 3 and 18 on dice, but leaves out those with severe mental handicap and anything above 18). One standard deviation--that is, approximately 15 IQ, depending on who you ask and whose test you're taking--is 3 INT. So, 19 INT is 145 IQ, approximately--not 190. Sorry, Sixchan.
Just based on die rolls of 3d6, ~0.5% of the population has 18 or higher INT (one in 216 die rolls gives you an 18). Extrapolating the bell curve out further: about 0.1% have 19 INT, about 0.02% have 20 INT, and about 0.002% have 21 INT--4 standard deviations from the mean, 10. In other words, you probably know someone with 18 or 19 INT. Given what I know about DnD players, you may well *be* that person.
For mine, I took 19 INT base +1 for fourth level. My mother would say I'm selling myself short, but mothers are great for boosting egos in the face of harsh facts.
Now, Celebrim, let's look at the criteria you listed (for brevity's sake, I'm removing one's I can't claim):
Celebrim said:
I'd like to throw in wit Sixchan and note to the various 18+ people exactly what that means in terms of intelligence.
Maybe you are 18 INT or higher, but what that means is one or more of the following:
1) In high school, you were a Jeopordy Teen Champion, National Merit Finalist, and were on a team that won several national scholar's bowl meets.
Parts one and three aren't INT; they're ranks in Knowledge (General). But yes, I have part two.
(Part one also includes a lot of luck to even get to try out).
2) When IQ tests were adminstered to you, not only did you always achieve perfect scores, but you also finished them faster than the fastest time category listed on the test. The results of most IQ tests you have taken had '+' appended to the end of them (160+, 165+, 180+, etc.), and your actually IQ is in doubt.
Yep, got that.
6) You finished high school before age 15, or else you finished your bachelor's degree in under 3 years from a prestigious university (MIT, Stanford, University of Chicago, Harvey Mudd, etc.)
Part one, yes.
7) You are so intelligent that you've deliberately choosen to hang out in Special Education classes because you feel more comfortable with retarded people than you do with normal people. You'd rather people didn't know how smart you are, because they always treat you like a freak.
Read my disclaimer above. Or talk to my shrink.
8) You've already won the Field prize in mathematics, or a Nobel prize in one of the scientific fields. You have been a chairperson in the Royal or National Academy of Science.
No, that would likely be about a level 16 expert with a 20-22 INT; earning a Field medal or Nobel Prize takes either decades of work and dedication to your field, or extreme amounts of serendipity (cf. Linus Pauling). Being Chairperson of the RAS or NAS, OTOH, does not require incredibly high INT; it does require 16+ CHA, 15 ranks each in Diplomacy and Knowledge (Politics) and the Leadership feat.
One last thing: Given what I know about people who play DnD, they're generally highly intelligent. For instance, unlike so many other 'Net message boards, I rarely see posts here written with such poor grammar that they make no sense. I would peg the *average* INT of a DnD player at about 13-14, that is, 80th percentile, around 115-120 IQ.
OK. There's my defense of those claiming 18+ INT, and defense of my own choice.
Edited: Missed a zero in the percentage for 21 INT.