Scratch

Hi Joe, It depends on how you have programmed the feature.

A couple possibilities:

"repeat until variable < 1"
...

or

(for something that's already in a forever loop or triggered often):
if variable < 1
   stop script

Would one of those work for what you're doing?

(Note: I suggested "variable < 1" rather than "variable = 0" just in case the variable goes below 0 before the code gets a chance to check it)

Oh, here's an easier way if you just want the variable itself to not go any lower than 0...
you can check before you subtract anything from the variable. (e.g., health)

"if health > 1
  change health by -1"

(so it won't go below 0).