Talk:General Rules/@comment-31130872-20170211022116/@comment-27029853-20170211041031

Generally the rule is that you can use an upgrade card once per trigger, some have additional triggers such as "once per round". R4-B11's trigger is "When attacking" so you can use him once per attack. Usually the trigger is included in the line with "When"

If they have the action header, like Gonk, then you can use it once per round, Gonk being the exception because it's two different actions (although the only way I know of that can do both in one turn is using Experimental Interface)