I posted this over on the Roll20 support forums but I figured I'd ask here as well.
Basically I want to incorporate bonus damage dice in my attack macros. Right now I've got this line:
/roll 2d20k1+10
/roll 1d12+8
For one of my Avenger's attacks. basically I want to incorporate that 1d6, but only have it rolled and added to the attack damage total if the higher of the two d20s is a 20. I'm not sure how to do that (or if such a feature has really been implemented) and the built in exploding dice feature /roll 4d6! for example adds another die to the first roll of the same type on a crit, but doesn't seem to over any other application.
Best Answer
I think the best you're going to come up with at this time is to add a macro for your roll so
And then a macro for each of your damage expressions, both the critical damage and also the normal damage so
And
You'll have to figure out when to roll which on your own.
The other option would be the set up your attack and regular damage as a macro and then have your critical damage as a second macro that you use to replace your normal damage roll in the even of a critical hit.
I still strongly recommend asking roll20 for native support, but this is a quick fix for now.