I have a question about the powers when you somehow have both Impervious and Invincible.

Say you are taking damage, you'd have to choose between Impervious or Invincible. Are you allowed to roll the d6 for Impervious before choosing which power to use? I'm leaning towards no because the d6 is part of using Impervious. But HeroClix surprises me a lot so I thought I'd ask.

Do you get to roll your dice before deciding to make an attack?
"oh, I only rolled a 7, I can't hit Superman but I could hit Green Arrow. I'll attack green arrow."

but instead say
"oh I only rolled a 3, I didn't make my impervious roll, I will use invincible instead"

same thing.

If you are rolling for it you have already made the decision.

Haha, good point. Thanks DarthUr.