Tony Vargas
Legend
Once again, wishing for the ability to both laugh and XP....
Added benefit: 20 pennies is cheaper than four dice!
So for PCs, would that be 20d2-keep-15?Eureka! (15d2)-12 conforms more closely to a normal distribution than any other dice-rolling method yet, and it covers the 3-18 range as well! Interestingly, it comes within 1-2% of the frequency of all results of 3d{2,3,3,4,4,5}, except for 10 and 11, which are slightly less likely using this method. I'd say the averaging method is a good approximation, but if the remote chance of rolling 3 or 18 is important, this method produces a distribution that's very close to what you'd expect to find in the real world.
Added benefit: 20 pennies is cheaper than four dice!