Crit vs Pen
Been playing Leagues for a while, still a little unsure on some things. I like AD, carry or brawler, or whatever they are called now. My question is really which should those champs focus? I usually get at least 50% crit then get Pen, but really, I want to optimize my purchases so which is the more optimal? I'm sure it is dependent on the champ, but some clarification between the two would help.