RulingHall of Heroes (rules 1.0–1.4)
Expansion card questions: Can I play (defense) cards or trigger (defense) abilities outside of an enemy attack, if the triggering…
Question
Can I play (defense) cards or trigger (defense) abilities outside of an enemy attack, if the triggering condition on the card is otherwise true? For example, can I play Jump Flip (“Hero Interrupt (defense): When you would take any amount of damage, prevent 2 of that damage. If you paid for this card using a resource, remove 2 threat from the main scheme.”) in response to Klaw’s Sound Manipulation (“…Take 2 Damage…”). It seems clear that Spider-Man’s Backflip would not be playable in that situation (as its play condition says “when you would take any amount of damage from an attack…”). In contrast, would Captain America’s Shield Block be playable vs Sound Manipulation or any other non-attack sources of damage (its play condition is only “when you would take any amount of damage…”)
Answer
In short, yes, you can play “defense” cards or trigger “defense” abilities in response to something that isn’t an attack. What’s important is that the triggering condition on the “defense” card itself was met. Jump Flip states that it can be triggered “when you would take any amount of damage” and does not specify that it has to be played after an attack. So, you could play Jump Flip in response to Sound Manipulation and prevent the 2 damage that would be dealt to you in hero form. (Klaw would still heal 2 damage, regardless.) Similarly, you could exhaust Shield Block while in hero form in response to Sound Manipulation being revealed and block the 2 damage. (Klaw would still heal.)
— Alex Werner, FFG Game Rules Specialist