@lown @Sandra @BPeylet Useful tool! I'd maybe want to change some things if I was ever using this, though.

I'd probably want the dice rolls that this finds to have a fixed damage modifier as well as a dice roll, and I'd probably want that fixed damage to be about 40-50% of the average damage. I'd want the damage done to be a little more consistently within a certain range of the average, and I'd also want crits (that in 5e are "double the dice, add the rest") to be less devastatingly swingy. This would also allow you to use the modifier to push the average to within half a point of the target.

Secondly, I'd want the various dice rolls presented to show me what the damage range would be in the more probable midsection of the curve. It's fairly simple to calculate the standard deviation of a dice roll, and 1sd either side of the average covers 68% (a little over 2/3rds) of the probability, so that would be a good measure of "most of the time it's in this range". I can explain this calculation if needed.