critical success and fumbles based on/calling an attribute (attr_)

How can you in a roll  display a critical success (and) critical failure based on an attribute? example (fallout): critical success = any result on 1d10  < the LUCK attribute (attr_luck)        and  critical failure is any result >96 so I want to roll 1d100 and display a critical failure on any result >96   and a critical success if the result < luck I already have this in my sheet for the roll command: /em @{character_name} rolls Barter skill [[1d100]], compared to [[ @{barter} + ?{Modifier|0} ]] EDIT: I tried in game following a technique given around here of the type: [[1d100cs<[[@{Total}]]]] It gives me this:         /em @{character_name} rolls Barter skill [[ 1d100cf>96cs<[[@{luck}]] ]], compared to [[ @{barter} + ?{Modifier|0} ]] Am I right??

That should work! If @{luck} is just a number, you could get away with removing the inline roll brackets surrounding it. One point to consider is that Roll20 interprets > as ≥ and interprets < as ≤. e.g. 1d20cs>18 will highlight green on rolls of 18, 19 or 20.

perfect! I will try it ! But luck is autocalculated based other fields, so I believe  the brackets are needed

Ah, if it's autocalculated, very likely.