A simple query roll like this should work for most of it. /r 1d100<?{Ability|0} ,this will do a normal roll and if you get under the ability value will tell you 1 success Roll = [[d100]] < Ability = [[?{Ability|0}]] ,this looks a bit more elegant but wont let you know if it is a success. The output is all in one line and gives you the information you need though. Something I would like to see is the support for 0 - 99 dice instead of just 1 - 100. Some of the percentile games treat a 00 as zero not 100. Just a suggestion that helps me when I run roll under percentile games, just turn them into roll over 100 games and add the ability or skill you are trying to roll under. This makes success easy to see and lets people compare contested rolls easier I think.