When is it alright to draw on someone physically attacking you without a weapon?

Going off the other post about the bar confrontation, I'd like to clear up when it's alright to draw on someone actively attacking you or your group with fists/kicking/ect. Is it always up to state law? Is there no common solution to when you can defend yourself? via /r/CCW http://ift.tt/2fQtNbf