Lets suppose we have a crossblooded sorcerer with serpentine and undead bloodlines. Here goes the text for their arcanas:
Serpentine:
Your powers of compulsion can affect even bestial creatures. Whenever you cast a mind-affecting or language-dependent spell, it affects animals, magical beasts, and monstrous humanoids as if they were humanoids who understood your language.
Undead:
Some undead are susceptible to your mind-affecting spells. Corporeal undead that were once humanoids are treated as humanoids for the purposes of determining which spells affect them.
So, how would these two interact? Would the sorcerer be able to enchant zombie animals, zombie magical beasts and zombie monstrous humanoids?
As a side question, undeads can be affected by mind-affecting spells with this bloodline. Color spray is mind affecting, so does it means they also get stuned and unconscious, even while being immune to such conditions? Or they're only affected by enchantments?
Don't think so. Technically there's no such thing as a "zombie magical beast" or "zombie monstrous humanoids".
The Undead type replaces their old type except in very specific cases (Vampires are Undead and Augmented <Original Type> if I recall).
An undead is an undead is an undead, this just lets you use mind affecting spells on corporeal undead who USED to be humanoids, it shouldn't interact with the other ability at all.
And what about spells like color spray? Their effects work even with undead immunities?
I don't see that they do interact.
You affect living animals, magical beasts, and monstrous humanoids as if they were humanoids. You can affect corporeal undead as humanoids if they used to be humanoids.
But an undead that used to be an animal, magical beast, or monstrous humanoids didn't used to be a humanoid, even if you treat living specimens as if they were.
I don't see that undead are immune to unconsciousness. Its just that normally they would never be in a situation that caused the condition.
Stunning is something they are immune to, and that immunity is listed separately from immunity to mind affecting effects. So I think they would keep the immunity to stun.
So if affected by Color Spray, an undead could be blinded and rendered unconscious.
This is kinda strange in concept (ex. skeletons have no eyes) but since undead are not immune to either condition (just normally immune to all known effects that cause the condition) they are still affected.
No, I've had this issue clarified by James Jacobs.
While Serpentine doesn't add anything here, undead (that used to be humanoids) would be fully susceptible to any effect that would normally fizzle against their undead immunities.
They could be stunned, blinded, put to sleep, charmed, knocked unconscious, subject to instant death (phantasmal killer), etc. They basically lose all type-based immunity.
I disagree with that opinion.
If you had a living creature that was immune to stunning, he could be affected by Color Spray and become blind or unconscious. He just wouldn't be stunned.
The effect of Undead bloodline allows mind affecting spells to affect undead. Other immunities are separate from the immunity to mind affecting effects, and shouldn't be ignored.
I disagree with that opinion.
And James' opinions should be given due consideration. That doesn't mean he can't be wrong.
And re-stating it is James' opinion doesn't make it more correct or stronger.
I have listed why I think it is incorrect. To answer James' question in the linked post:
What it does is let your spells affect them as if they weren't immune to them.
It means they could be given morale bonuses from Good Hope, or penalties from Crushing Dispair. It means they could be rendered Unconscious or Blind from Color Spray, or Charmed and given a Suggestion.
It means plenty. But it doesn't say that it also deprives Undead of their immunities other than Mind Affecting effects.
Immunity to all A) mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
Immunity to B) bleed, death effects, disease, paralysis, poison, sleep effects, and stunning.
Not subject to C) nonlethal damage, ability drain, or energy drain.
Immune to D1) damage to its physical ability scores (Constitution, Dexterity, and Strength), as well as to D2) exhaustion and fatigue effects.
Immunity to E) any effect that requires a Fortitude save (unless the effect also works on objects or is harmless).
Not at risk of death from F) massive damage, but is immediately destroyed when reduced to 0 hit points.
It says you can do A. It doesn't say B-F too.
It bypasses all mind affecting immunities for undead, in other words
Immunity to Stunning isn't any part of "all mind affecting immunities," and shouldn't be included in such.
That's fair. I agree that the devs can be wrong about what is written, but I don't think they can be wrong about what the rule is supposed to be. I've ignored them from time, to time, though, so that's fine.
That said, I'm of the mind that if it doesn't bypass all their immunities (for mind-affecting effects only, of course), then it's a useless ability. So, I'd rather have the ability be useful than literal, and a developer backing that up is plenty for me to assert that position as truth.
They definitely can be wrong about what the rule is supposed to be. Even the writers of particular rules have been "wrong" about what their own rule is supposed to be as later stages of the dev process change the effect of the rule.