Of one could input the above formula into a spreadsheet and replace N with a cell reference, use that to generate the averages for all the dice.Yes, the average is always the same for a given set of dice. Each N-sided dice has an average of (N/2 + 0.5), so - for example - 3d10 + 6, have an average of 24.5. Probably, I'm not actually understating the question, though.
Then use the base average damage for each dice to generate tables or divide the target number by the expected damage for a die or subtract the bonus and divide the remainder by the average damage.I know I can calculate this myself, but it would make my life easier if there was such a table.
I'm referring to when a monster's stat block or similar says X (YdZ+W) damage. So if I know I need in the region of 17 average damage, or 35 average damage, or whatever, I can just lo9k at the table and see what's closest.
I figured someone on the internet must have made one but my google fu is weak. I'd like to make a little web app to do it, if I can find somebody who's done the tedious work first.