All the rulesets so far seem to claim a basis on 3d6 dice rolls. The individual probabilities of the outcomes of a 3d6 roll are as follows:
Roll Freq Prob
3 1 0.5%
4 3 1.4%
5 6 2.8%
6 10 4.6%
7 15 6.9%
8 21 9.7%
9 25 11.6%
10 27 12.5%
11 27 12.5%
12 25 11.6%
13 21 9.7%
14 15 6.9%
15 10 4.6%
16 6 2.8%
17 3 1.4%
18 1 0.5%
The highest probabilities are in the middle as you would expect, with a mean value of 10.5 that you can't actually roll. A score of 18 means you are in the top 0.5% of the population for that ability. A score of 17 means you are in the top (1.4 + 0.5) = 1.9% of the population, and so on where you add up the probabilities as you go down the list. As I mentioned earlier, the IQ score for intelligence is probably the only other "real" score that has relevance to 3d6 stats. There are many IQ tests, but if you assume the standard test is defined by a mean average IQ of 100 and a standard deviation of 15, then a person with a 115 IQ would be in the top 15.8% of the population. Looking over at the 3d6 table above, that equates to a D&D score of about 14. My guess is that a lot of people on these boards have higher real life INT scores than they might realize.
Also, you can watch Vasilily on Youtube. He is very impressive, and he does not look like He-Man at all.
