Why are undead immune to mind-affecting effects?

[Starbuck_II]

That is an interesting approach. But the problem is, Elementals are NOT immune to mind-affecting effects. Surely a large mass of Fire should not have grey tissues.

Elementals aren't completely empty though.

Otherwise a nonmagical sword wouldn't cut them.

 

[Sphyre]

That is an interesting approach. But the problem is, Elementals are NOT immune to mind-affecting effects. Surely a large mass of Fire should not have grey tissues.

That's not a problem with the explanation, but rather that you're trying to apply it to something different.

I have the same view on why Undead (whether mindless or not, their brains do not dictate their actions, but rather the negative energy that empowers them to be animate - which is why necromancy spells can change the way undead act) are not affected by mind-affecting effects.

Elementals may have a different reason as to why they are affected by mind-affecting. Just because undead have a reason they are immune to mind-affecting effects does not mean that all things that share some things in common (such as being immune to critical hits) must be within the same group and use the same reasoning. (In otherwords, just because 2 and 9 are both positive numbers, it does not mean that they are both even numbers because there exist even positive numbers)

One hint as to why the designers made elementals not immune to mind-affecting abilities could be due to the fact that they actually have a living body, even if it's partially composed of an element.

 

[Tetsubo]

I see the difference between a living mind and an undead mind much like the difference between a live musical performance and a recorded performance. One is just an echo of the other.

 

[VanRichten]

That is an interesting approach. But the problem is, Elementals are NOT immune to mind-affecting effects. Surely a large mass of Fire should not have grey tissues.

Elementals are immune to mind affecting effects.

 

[Shin Okada]

Elementals are immune to mind affecting effects.

No they aren't. It is a common misunderstanding. But while they are Immunity to poison, sleep effects, paralysis, and stunning, they are not immune to mind affecting effects.

 

[Kerrick]

The Inevitables are constructs with Int scores, as is the homunculus.

You are correct, sir. I forgot about them.

I'm more inclined to go with "the brains of nonliving creatures are fundamentally different from those of living creatures - so the stuff that messes with constructs and undead are fundamentally different (e.g., Control Undead is Necromancy, while Charm Monster is Enchantment).

With constructs, that's pretty much a given - they don't have "brains" as such; even inevitables are programmed. With most undead, you could also use that argument, though there are a couple (ghouls and vampires leap to mind) that are sufficiently close to "living" that they might conceivably be affected. Ghouls, though, are driven mostly by instinct, so we can drop them; vampires... that's a tough call. I think I'll just stick with "undead can have their mental ability scores damaged" (as it says in the MM) and leave it at that.

That is an interesting approach. But the problem is, Elementals are NOT immune to mind-affecting effects. Surely a large mass of Fire should not have grey tissues.

They're still living beings. An elemental is a spirit taken form by accumulating a huge mass of matter - air, earth, fire, or water - around itself. It is sentient (though barely), and therefore falls under the qualifications for "able to be affected by mind-affecting spells" (said qualifications being "living" and "sentient".

 

[HeinorNY]

I started thinking about this today.

This is the answer.
Mindless undead do not think. They have no conscience. They don't make choices. They are deterministic creatures. They have only animation.

 

[Voadam]

Its a poor design decision in 3e IMO, I removed the immunity for my games.

Same thing for plants like treants and constructs etc. I keep mindless as immune to mind-affecting and feel that it is a superior line to draw for the immunity. In my game you can charm the mind of a treeman but not a non-sentient fungus or an undead/construct automata.

Mind affecting spells often have a humanoid/other intelligent creature demarcation anyway with spells like 1st level charm person versus 4th level charm monster.

 

[Voadam]

The mechanical impact on games of removing the rule is that these type of sentient creatures will be able to be affected by color sprays and charms etc. It impacts how many foes the beguiler's attack spells are effective against in particular as well as illusionist and enchanter specialist wizards/sorcerers.

 

[Voadam]

With constructs, that's pretty much a given - they don't have "brains" as such; even inevitables are programmed. With most undead, you could also use that argument, though there are a couple (ghouls and vampires leap to mind) that are sufficiently close to "living" that they might conceivably be affected. Ghouls, though, are driven mostly by instinct, so we can drop them; vampires... that's a tough call. I think I'll just stick with "undead can have their mental ability scores damaged" (as it says in the MM) and leave it at that.

There are more than that even sticking just to core.

Allip, insane but int 11 with a special defense against certain magics going into their minds

Bodak int 6

Devourer int 16

Ghost, same int as the base creature

Ghoul int 13

Lacedon int 13

Ghast int 13 but "far more cunning" than their lesser ghoul kin

Lich: gains a +2 int bonus

Mohrg, int 11

Mummy int 6

Mummy lord int 8

Nightshade int 20

Nightwalker int 20

Nightwing int 18

Shadow int 6

Shadow Greater int 6

Skeleton - Mindless

Spectre int 14

Vampire int +2

Vampire spawn int 13

Wight int 11

Wraith int 14

Dreadwraith int 17

Zombies - Mindless