Undead under Undead Anatomy

Question

The Undead Anatomy spell description says:

In this form, you detect as an undead creature (such as with detect undead, but not with magic that reveals your true form, such as true seeing) and are treated as undead for the purposes of channeled energy, cure spells, and inflict spells, but not for other effects that specifically target or react differently to undead (such as searing light).

If a Lich, Vampire, or some other undead casts Undead Anatomy on itself, does the spells effect hold true?

Answer 1

Yes, because the spell’s authors and editors did their jobs poorly.¹ The author seems to assume that “You” as specified by the spell’s target are a humanoid creature, even though there is absolutely no reason to assume that’s true, seeing as all manner of non-humanoid creatures are capable of casting those spells. It’s particularly absurd with creatures that are already undead, but a dragon casting undead anatomy being required to become a kind of humanoid-ish undead seems rather like a mistake.

But trying to abuse the “not for other effects that specifically target or react differently to undead” clause when you, yourself, are already undead is a recipe for arguments and, quite frankly, being asked to leave the game. Pathfinder is often poorly written, and even more often poorly edited,¹ and part of agreeing to play a game of Pathfinder is agreeing to shoulder some responsibility for mitigating the failures in authorship and editing that the rules text is rife with. It’s pretty clear from your question and comments that you don’t think this is right or reasonable, that you’re just trying to take advantage of the mistake. If I were your GM and I came across this Q&A, and then realized “oh that’s how he avoided the searing light last session?” I would be pretty annoyed at you and seriously questioning whether or not your continued presence at the table is a net positive for the game.

1. _{This answer is pretty harsh on the writing and editing here, since this is a pretty stupid mistake all things considered, and Paizo is literally in the business of selling their supposed care and expertise here—this product is not offering what the customer paid for. Ultimately, though, the problem is likely not with the authors or editors per se—rather, it’s the business practice of churning out cheaply-made supplements at an absurdly tight schedule that causes these problems. Which Pathfinder has in spades. The people who did their jobs poorly here were, to a large extent, set up to fail. To be even more fair, though, there is so very little money in the RPG industry that it’s pretty likely that it would be impossible to support a product like Pathfinder as a profit-seeking company without measures like this.}

Answer 2

Your question seems to focus on the last part - that after the transformation, you are treated as an undead for the purposes of certain spells, but not for other effects that specifically target undead.

And what you want to know is whether, if a lich casts this spell, does he now not get treated as an undead for the purposes of spells like searing light?

There are two ways to read this effect:

1. The spell changes your type to undead with respect to detect undead, channeled energy, cure spells, and inflict spells. It does not change your type for other effects, such as searing light (so, you keep whatever type you had previously).
2. The spell changes your type to undead with respect to detect undead, channeled energy, cure spells, and inflict spells. It changes your type to "not undead" for other effects, such as searing light.

I think the first reading is more in keeping with the spell text. The point of the spell is it changes you into a particular undead creature, and gives you some of the effects of being that undead creature, but in all other ways you stay the kind of creature you were originally. It doesn't add a vulnerability to searing light, but also does not take away that vulnerability.

So the lich turning into a skeleton by use of this spell is still just as affected by searing light as he was originally.