Critting On a Specific Number

Hello! I'm using the D&D 5e character sheet made by Roll20 and need some assistance. I'm looking to add a set of original weapons with the "Lucky" prefix and I hope to be able to make the weapon have a critical success on a 7 , but not have a crit range of 7-20. Is there any way to do this within the character sheet so my players don't need to type out the attack manually every time? Thanks in advance!

The Crit Range in Attacks & Spellcasting will do this for you. Basically the sheet already fills it in with {{r1=[[1d20cs> then it reads your crit range, so you're stuck with a 'greater than' operator. But if you do this for the Crit Range: 20cs7 it'll still crit on 20 (and over), but also on 7. If you don't want the 20 to still be a crit, just change it to 21cs7 to move the 'greater than' range outside the range of the die.

And, if you want the 7 to be a different color, you could do this to make it highlight blue (while still having 20 green and 1 red): 20cs7cf7cf<1