Minimum value of 0

In a regular Character Sheet macro, I'm trying to calculate damage for weapons. This in itself is simple enough, except for Armor and Armor Piercing. Armor works simply as damage reduction, but Armor Piercing reduces the value of Armor, but not below 0. So a target with 2 Armor that is hit with an AP 4 weapon has 0 Armor against that weapon.   Simple enough, right? But how to I make that function stop at 0? Or is there a way to drop anything lower than 0?

You can use the keep highest function, where you wrap two or more numbers in { }kh1, like {0,@{strength}}kh1 The problem is that with kh, all values must be the same type. If one is a dice roll, all must be dice rolls. You can get around this by using 0d0 as a fake dice roll, like {0d0,[[1d6-3]]}kh1 This will not let the roll go below 0. There can be difficulties using this in more complex roll macros, so if you have issues getting it to work, post your roll and we'll help you.