I'm just logging this here for the record...
This came up after someone realized it's possible to have maps in Temple of the Deceived that are impossible to win (fantastically unlikely but a cool little discovery, check it out here ). In brainstorming ways to get around the map lock, someone else brought up using Forth Eorlingas! to attack the Temple Guardian, which says:
Combat Action: Each Rohan hero can be declared as an attacker against enemies in the staging area this phase.
It kind of seemed like Forth shouldn't work, as the Temple Guardian is Immune to player card effects, but it wasn't actually completely clear to me that Forth Eorlingas! doesn't work the same way that Quick Strike does: make some sort of modification to the declaration of "framework" attacks. Since Immune enemies are (of course) still susceptible to framework attacks, maybe Forth could work...? (As per the FAQ, Hands Upon the Bow cannot be used against Immune enemies because it forces targeting/choosing of the enemy. Note that this bars Dunhere and Haldir too.)
I sent in an official query to get the final word, and here's what I got:
The distinction between Quick Strike’s effect and other similar effects is very subtle, so I understand the confusion around the different rulings. Basically, Quick Strike only works because it allows you to attack an enemy that you could typically attack. It just changes the time at which that attack takes place. The reason that effects like Hands Upon the Bow and Forth Eorlingas! do not work against enemies that are immune to player card effects is because you can’t typically attack an enemy in the staging area.
So all remains sane. (Except perhaps the fact that Quick Strike does work at all against Immune enemies, but that's another discussion...)
Edited by sappidus