This only applies to raids. Say you have one hundred numbers 1-100 Say the game can pick two of those numbers when you beat a boss. So, the game picks 47 and 19. Well, look is only awarded for certain numbers. Let's say those are any number between 24-50 and another item for 80-100 So, you got 47! You get an item! Aww, you also got 19. No item on that one. It's pretty simple. Edit: they should have used the form of rng that removes numbers from the pool as you get them making it so that something would drop eventually. After that drop they would put all the numbers back and you would start the process over.