Card Text Edit
"While attacking you may exhaust this card to add 1 red die to your attack pool. If you do, remove 1 die from the attack pool."
Rules Clarification Edit
While you are resolving this card’s effect, you cannot resolve other effects that modify dice until you have completely resolved this card’s effect.
FaQ Version 3.3.1; Dec. 2017
Available Through Edit
The effect of this Upgrade Card triggers during Attack Step 3: "Resolve Attack Effects"