Got this from the spoilers that Vitamin T posted:

"Hellstorm Rocket Battery - Support - 1 EE - Siege, War Machine - Battlefield, Action - Spend 3 resources to deal 1 damage to target attacking unit. Then, move it to another zone controlled by the same player."

Does that mean that the attacking unit no longer counts as "attacking"? Say I move it to the Quest zone, how does that work exactly? My instinct is that it would no longer contribute power and no longer be in the combat.

Then could I do the following with this card?: Say my opponent attacks with 3 units that have actions upon attacking (for example 3 Blood Dragon Knight s), he can take 1 of their actions, then I can take the Rocket Battery action to blast one of his other two Knights that have not taken their action yet into the Quest zone, and they will no longer be able to trigger their ability? Is that correct? Or did they already satisfy the requirement to use their ability of "When this unit attacks..."?

FAQ 1.5, p11 :

When an attacking unit is moved out of the battlefield, that unit is no longer considered to be attacking.

So yes, the unit no longer attacks.

About the blood dragon example, After they're declared attackers, an action window is opening, so you can trigger your action, and blood dragons can all trigger their action in response, so they would deal their damage and them be moved out.

Budmilka_fr said:

Thanks for the response and the FAQ reference. With respect to the second part, I thought that the active player would go first, so he would declare one of his Knights as taking the action, then I could respond with the Rocket Battery. If he doesn't trigger the Knights so that they could all respond to the Rocket Battery, couldn't I just pass and then I declare defenders and he has missed his chance?

I think he must not wait to respond to the Rocket Battery. In my mind it doesn´t matter when you play the action of the Rocket Battery. It is important for the guy with the Knights to play their abilities as soon as possible, when the conditions (attacking) are fulfilled and the target is legal at this moment. But if the abilities of the Knights are on the action chain, they will happen. You should not have a chance to prevent the actions from the knights with the Rocket Battery.

Feel free to correct me.

FAQ 1.5, Page 8, Card Effects:

After card effects are triggered (usually by paying a cost or meeting a timing requirement and declaring its use), they exist independently of the source.

There are two things that are important here. First is the order of triggering the "when this unit attacks" actions. Those are Triggered Actions, so they must be used at the first available opportunity. So it goes like this:

• Declare 3 Blood Dragons as attackers. (Their ability is now waiting to be optional triggered by this player)
• Action window opens.
• From B-1 of the flowchart, players take turns putting Triggered Actions on the stack. This means that all 3 Blood Dragon actions go on the stack, because the other player has no "Triggered Actions"
• Now, in response, you can play Rocket Battery and move 1 Blood Dragon.
• It resolves in reverse order, so the Blood Dragon is moved to quest.
• Then the 3 Blood Dragon abilities resolve. All of its conditions are still valid (deal damage equal to its power to target unit in the defending zone.) It still has power and the target unit is still in the defending zone, so it resolves successfully, regardless of whether the Blood Dragon is still attacking. It doesn't need to meet its trigger condition (when this unit attacks) again at resolution.

Schmutzer is right that there is really no way for you to prevent him from triggering his Blood Dragons using Rocket Battery, because you can't use Rocket Battery until they attack, and once they are attacking, their abilities will go on the chain even if they are moved (destroying them would prevent their ability from resolving successfully, because they would no longer have power).

Entropy42 said:

What, where's the love for Bright Wizard Acolyte ?

Thanks very much for the responses!