Can healing spells provide an infinite brain supply for my mind flayer?

Question

So to build on my question, What are the consequences for an illithid rejecting his brain diet?…

To recap, I'm designing an NPC for a non-D&D campaign (but I'm using D&D as my setting inspiration). The NPC is a rogue illithid, fighting against his own race. He will be chaotic evil or chaotic neutral, I have not decided yet. But while he does this it is simply too dangerous, or too tedious, to hunt for brains.

Taking 5E as the main rule source (but If you want to use 3.5 or Pathfinder it's still OK), this illithid knows arcane spells as well as standard mind flayer magic and some illithid alchemy/bioengineering.

Could he keep some slaves around and eat their brains, then cast some healing spell on them to regrow them? I imagine the slave would become completely oblivious to everything, since all his memories would be deleted over and over.

Answer 1

Possibly — if you count spells that bring back the dead as healing. But, this ain't cheap (in 5E — earlier editions might have other answers). The Mind Flayer's "Extract Brain" says:

If this damage reduces the target to 0 hit points, the mind flayer kills the target by extracting and devouring its brain.

So, the victim is definitely dead: too late for a quick application of a healing potion, Cure Wounds, or other basic healing spells. We need a bigger ... boat.

Next up might be Revivify, which returns the recently-deceased to life, but it says:

This spell can’t return to life a creature that has died of old age, nor can it restore any missing body parts.

If you made a list of "degree to which a body part can be missing", "extracted and devoured" is way up there. So, that's no use.

And Raise Dead has a similar limitation:

This spell closes all mortal wounds, but it doesn't restore missing body parts. If the creature is lacking body parts or organs integral for its survival — its head, for instance — the spell automatically fails.

So, you're going to need the 5th-level druid spell Reincarnate (which grows a whole new body) or 7th-level bard/cleric Resurrection (which grows back missing body parts). Both of these consume a 1000gp component.

That's possible, but... your mind flayer will have to decide if this particular brand of evil is an economically viable proposition compared to other options.

Answer 2

The Ring of Sustenance from 3.5/pathfinder may suit your needs.

Among other things:

This ring continually provides its wearer with life-sustaining nourishment.

Answer 3

Revivify is only third level, and only costs 300gp, so that's easier to do. Revivify doesn't restore body parts, but if he keeps a creature captive that is (a) sentient, and (b) regenerates, then that might do. Eat brain, Revivify to restore life, allow regeneration, repeat. An Oni (Ogre Mage) or Troll might do.

Answer 4

Yes they can, if your story says so

I'm going to challenge the frame of the question. Should any rules from the PH restrict worldbuilding? Should the rules trump the story?

The point is, you're trying to reduce all the magic in your world to a spell list from the PH. Why? These spell lists are named "Cleric spells", "Wizard spells", therefore imply spells available for a specific class. But NPCs and monsters do not have classes in 5e. Leomund invented his Tiny Hut spell, despite of the fact there are no rules about inventing spells in the PH.

Unless your illithid is a player character, you don't have to restrict its lifestyle with the PH.

You shouldn't restrict its lifestyle with the MM either. Yes, in combat an illithid can kill you fast by sucking your brain out. That doesn't mean it can't eat brains any other way. Say, eat it slowly. Eat a half of a brain. MM Actions describes combat moves or special abilities of a creature. It doesn't describe its "normal" peaceful behavior - a creature can eat, play, feel, sing, laugh — without Actions described in its stats block. Additional source books like VGM or XGtE describe additional things about world, but "additional" is the key word here - these books add to the world, not restrict it. You, the DM, is the ultimate source of information about your world.

Fun > Story > Rules

Consider distinguishing game mechanics from game fiction. The DMG, page 235 says:

The rules serve you, not vice versa.

As a DM, you help guide the narrative and bring the world of the adventure to life. From this perspective, the rules is not your straitjacket, but your tool.

Even PH rules can be changed in favor of story and/or players:

"As DM, I allow changes to characters/classes/etc. whenever it serves the story. The beauty of D&D—it’s infinitely customizable"

(Jeremy Crawford on twitter)

So the real question is — this feeding slaves illithid facility, is it good for your story? Would your world be better (in terms of storytelling) with or without it? Ultimately, will it make the game more fun to play? You're the DM. It's up to you to make a decision.

Lorewise, probably no

If your world is meant to be consistent with the D&D lore, then illithids probably can eat a person only once. While devouring a brain, the illithid consumes not only the brain tissue, but also memories, personality, innermost fears and psychic energy, which is necessary for them:

The brains provide enzymes, hormones, and psychic energy necessary for their survival.

An illithid experiences euphoria as it devours the brain of a humanoid, along with its memories, personality, and innermost fears.

(MM, page 221)

A healing spell can hardly restore all these things, so a regrown brain will be probably not nutritious enough.

Answer 5

What you need to do is get yourself a properly restrained troll. Since they regenerate indefinitely unless you use acid or fire, you can just keep sucking their brains out. However, as with everything in D&D, whether or not this works will be up to DM interpretation.