Comparing against the sum of dice instead of individual dice

I'm trying to make 3d6cf<3cs>18 work like 1d20cf<1cs>20 but instead of comparing against the sum of 3d6, it compares each individual die against 3 and 18. Is there a way to make Roll20 compare vs a sum?

Not really. The custom crit ranges evaluate the die roll, not the final results. If *ANY* of the dice are crit fails or successes, the result will be red or green. If it contains both crit fails AND successes, it will be blue. You can hover your mouse over the result to show the individual rolls.

I'm going to also assume there's no way to make the dice explode only on an 18 instead of whenever a single die rolls a 6?

Correct. The roll modifiers act on the die, not the total. What system or mechanic are you rolling up, here, btw? Often times there are more creative solutions to a need than a straight-up dice roll mechanic

You could just use this roll to simulate 3d6 /r d18!r<2 This will explode on an 18 and whenever the "d18" comes up as a 1 or 2 it will reroll it. You could do this with any rolls that involve multiple die and you need the sum of the rolls. How you do this roll is the following /r dXr<Y Where X is the maximum possible roll, and Y is 1 less then the number of die (aka 1 less then the minimum possible roll). Depending on the number of tries it needs to roll above the threshold it might clutter up the chat window. To avoid that you can just do whole roll like this: /r [[d18!r<2]]

*Not* a Math person by any stretch, but isn't the probability skewed by using d18 over 3d6 ?

Yes, 1d18r<2 (or better, 1d17+1) does substantially increase the odds of the high and low ends and decrease the odds of the middle as compared to 3d6. Personally, I'd just handle the exploding manually: manually handling something that comes up an average of once every six dice (or a bit more than two out of every five 3d6! rolls) is obnoxious, but manually handling something that only comes up once every 216 3d6 rolls isn't that bad.

Yes, the probability is skewed badly by switching between multiple and single dice.

True I did forget about that part, but outside API access I don't think achieving that is possible. (I don't have access to it but it should be easy to do with a conditional loop) Btw I'm not why you brought up the 1d17+1 since that gives 2-18 insted of 3-18. The whole reason I didn't suggest using d16+2 is because if you roll a 16 it won't add another 2 to the total wich it shlould if you are trying to approximate the regulard 3d6 exploding.

Mark G. said: Correct. The roll modifiers act on the die, not the total. What system or mechanic are you rolling up, here, btw? Often times there are more creative solutions to a need than a straight-up dice roll mechanic I'm rolling my own system and just seeing what's possible on Roll20. If either of those had worked, it might have had some say on how the system forms. I'm not sure if I'm giving up on the odd mechanic, or if I'm just giving up on running this one game on Roll20. Thanks for the help though, everyone.

Zsolt S. said: Btw I'm not why you brought up the 1d17+1 since that gives 2-18 insted of 3-18. The whole reason I didn't suggest using d16+2 is because if you roll a 16 it won't add another 2 to the total wich it shlould if you are trying to approximate the regulard 3d6 exploding. Right, I even started writing "1d16+2" and then stopped myself, thinking it was wrong. I'd be able to post much more coherently and correctly if work would just stop distracting me from the important stuff...