Leokula gives a perfect example to simplify this: you can always "fail" to spot anything the game tells you to, facing the consequences as appropriate. So, if you have a card that says to spot 3 twilight tokens and there are 7 out, you can fail to spot the other 4, only spotting 3. Same with the conditions, in the example I gave before, you can fail to spot the third counter on
Final Count. Makes it easier to understand?