So if a good aligned rogue wants to swipe a Book of Vile Darkness, a minor artifact, from it's resting place which would cause 5d6 points of damage to him for merely touching it, he can "emulate" evil with his Use Magic Device skill and pick it up with out damage, because it's an item.
But he can't fool a mere spell? He has some completely unfathomable ability to "emulate alignment" to an item, but as soon as it isn't an "item" it doesn't work anymore?
I would argue that fooling that Artifact should be MUCH harder than fooling a mere forbiddance spell. That's exactly the kind of stuff a rogue needs to do. Get past magical protections. Convince the authorities he isn't evil, so he couldn't be to one who did that vile crime. Etc...
To me it sounds like a perfectly reasonable and intelligent use of a skill. If he can fool an item made with magic, then surely he can fool a spell too, by simply doing the same "whatever" that he did while fooling the item.
Obviously we can't argue any physics or realities here, but to me it's just a game balance vs. internal consistency argument. I think he should get it for the logical (to me anyway) reasons I noted above. If you think he shouldn't for game balance reasons, thats cool too. But does anyone have any reasons why there is anything fundamentally different between fooling an item and fooling an area of effect from a spell? You might argue that whatever the rogue is doing to "emulate" has some visual component to it, and thus may not be entirely effective when trying to fool someone that is casting know alignment on you. But perhaps in conjunction with a bluff check, I'd allow that too.
