Is taking down a mind flayer colony impossible in practice?

[rondragon123]

Thinking about making a campaign focused on taking down a mind-flayer colony
but given that they have dominate monster 1/day for each one, and that they are acting as a hivemind, I really don't see how even a 4 max level party can take a full colony down. Am I missing something or is this truly impossible?

[MaxWilson]

Thinking about making a campaign focused on taking down a mind-flayer colony
but given that they have dominate monster 1/day for each one, and that they are acting as a hivemind, I really don't see how even a 4 max level party can take a full colony down. Am I missing something or is this truly impossible?

Counterspell, Paladin of Devotion (prevents charm and therefore prevents domination), Darkness/Greater Invisibility (prevents being seen and therefore prevents Dominate Monster), and Mind Blank come readily to mind.

And of course you can always starve them to death. Use ranged weaponry + mounted combat to shoot them to death from way outside spellcasting range whenever they come out of their colony, and they won't get any fresh brains. Eventually they'll have to all leave via Plane Shift to avoid dying, but Plane Shift isn't precise enough for them to come back to the colony while avoiding your siege forces.

The siege approach would be appropriate if there were thousands of mind flayers in the colony. If there were only dozens you could just storm it with high-level PCs under Darkness/Mind Blank/etc.

[Xihirli]

Protection from Evil and Good is a first level spell.

[Protolisk]

Max level parties have options like Divine Intervention, multiple 9th level spell slots, and barbarians and moon druids who are near impossible to kill. At extremely high levels a colony attack could be easy. If a party built their characters organically and knew they were up against ilithids, or you told them ahead of time for a one shot, they can easily plan ahead for the Int saves via wizards, Resilient (Int), or spells like Mind Blank to make their heaviest hits ineffective, or the Cha saves in similar manners.

[rondragon123]

Counterspell, Paladin of Devotion (prevents charm and therefore prevents domination), Darkness/Greater Invisibility (prevents being seen and therefore prevents Dominate Monster), and Mind Blank come readily to mind.

what about mind blast? a full colony of mind blasting creatures will surely be too much even for what you said.

[LudicSavant]

what about mind blast? a full colony of mind blasting creatures will surely be too much even for what you said.

Mind Blast is Save Negates, and only DC 15. So for example, a Wizard with +5 Int, +6 proficiency, and +3 to saving throws would make that 100% of the time.

Anyways, how big is this colony we're talking about?

[darknite]

Mind Blast is Save Negates, and only DC 15. So for example, a Wizard with +5 Int, +6 proficiency, and +3 to saving throws would make that 100% of the time.

Anyways, how big is this colony we're talking about?

That's nice for the Wizard. Everyone else will fail at one point or another.

[LudicSavant]

That's nice for the Wizard. Everyone else will fail at one point or another.

What part of "for example" made you think "this is literally the only way to do it"?

[MaxWilson]

what about mind blast? a full colony of mind blasting creatures will surely be too much even for what you said.

How many illithids are in your hypothetical "full colony", dozens or thousands? Mind Blast is a nice, medium-ranged AoE against a save that is weak on most PCs and monsters, but after a whole campaign focused on illithids I wouldn't count on PCs not adapting. (Paladin auras, Bardic Inspiration, Bless, etc.) Then it's just a question of numbers. Dozens shouldn't be a problem for max-level PCs, especially if they find a way to defeat them in detail. And there's always Meteor Swarm...


That's nice for the Wizard. Everyone else will fail at one point or another.

So the Paladin fails a save 10% of the time (for example--exact numbers will vary), so if he ever faces ten Mind Flayers at once he is likely to get stunned. Why does this make you think the campaign is impossible? Again, how many mind flayers are we dealing with here? Unless the answer is "thousands", failing the occasional save vs. Mind Blast will not defeat the PCs.

If the answer is thousands, they should switch to siege tactics and starve the mind flayers of brains.

[LudicSavant]

How many illithids are in your hypothetical "full colony", dozens or thousands? Mind Blast is a nice, medium-ranged AoE against a save that is weak on most PCs and monsters, but after a whole campaign focused on illithids I wouldn't count on PCs not adapting. (Paladin auras, Bardic Inspiration, Bless, etc.) Then it's just a question of numbers. Dozens shouldn't be a problem for max-level PCs, especially if they find a way to defeat them in detail. And there's always Meteor Swarm...

This.

Heck, Resilient (Int) + Paladin Aura + Bless is already +12-15 to Intelligence saves. Throw on a Cloak of Resistance and a 12 Int and you're fully IP-proofed against all those pesky Intellect Devourers and Mind Blasts and so forth. Not "truly impossible" at all.

And there are many other ways of being able to approach large groups of foes, too. Divide and conquer, siege, vision control, all kinds of things. And actually killing high level adventurers is harder than just extracting a brain from their skull; high level PCs have access to a variety of "cheating death" type abilities.

[nickl_2000]

We are talking a Max level PC party who knows the location of a Mind Flayer colony? At that point they would just go recruit a whole boatload of Gith and just sit back and watch the chaos. By level 20 you should have communications with other planes and you can bring some in.


Other than that, hit and run with ranged attacks further out than a Flayer can hit (Spell Sniper and Ranged weapons should be able to do this). Counter Spell and Dispel Magic as other

[Xihirli]

Mind Flayers do not have a lot of hit points, and their AC isn’t very good for late tiers. The thing about them is they can be very dangerous when their stuff lands: dominate monster is very powerful, and the Stun is pretty good too. But late tiers alter that a lot. By the time you hit level 12 you’ve probably figured out how to prepare for domination effects. Raging berserkers can’t be charmed, Samurai have WIS proficiency and Indomitable, Wizards are pretty safe and can give another party member complete immunity to being charmed by aberrations. Druids have INT/WIS, Paladins have absurd WIS saves, and high level rogues also have WIS/INT.
At lower levels the stun is pretty scary but at high tiers when your friends can kill a mind flatter pretty quick after the stun it’s less of an issue.
I had two level 15 characters going through a colony trying to capture the elder brain. I gave the colony multiple ulitharids, a mind witness, two brainsteeler dragons, several dozen minions of varying types (enslaved lizard folk, grell, those walking brain things) and even included a Tarrasque in there for fun. Neither of the players dropped and none were dominated for more than a round before the other killed the offending mind flayer. Because I told them it was a mind flayer one shot and they prepared for it.
Both in and out of universe, Illithid are very dangerous to spring on people not ready for them but if you’re specifically preparing for them they’re not so tough. Just ask the Gith.

[Ason]

In older editions one common tactic against mind flayers was using golems and undead minions. If I recall, those creatures were flat-out immune to most mental attacks and could simply bash squid-faces into bloody pulps. It's tough to use mental powers against something that doesn't have a mind to begin with.

In 5e, most undead lose their psychic protections save for the revenant (which gets resistance to psychic) and certain boss level undead monsters (who you'd have a hard time recruiting or creating). But constructs (golems, clockwork creatures, animated weapons/armor/etc) are often still immune to psychic damage and charm effects and also lack brains, which makes them perfect minions for cleaning out mind flayer colonies. The big remaining problem your construct minions would have is mind flayers' ability to levitate at-will. I think animated weapons and the like have a fly speed though, so you might be able to use those to harass flying flayers while golems take out anything left on the ground. Flayers usually design their colonies to force attackers to use levitation to get around, however, so most constructs would have difficulty navigating but could effectively shut down a level from flayer control once they get there.

So to answer your question, in my opinion the easiest way to clear out a mind flayer colony is to have a wizard/artificer build some constructs, send those things in ahead of the party, and then have the wizard's party come up behind the constructs to deal with any unusual problems, give new orders, investigate, etc.

[KorvinStarmast]

We are talking a Max level PC party who knows the location of a Mind Flayer colony? At that point they would just go recruit a whole boatload of Gith and just sit back and watch the chaos. By level 20 you should have communications with other planes and you can bring some in. This, right here. That's why the party accumulated all of that treasure ... to offer the Gith a bit of coin for the raid.

[darknite]

What part of "for example" made you think "this is literally the only way to do it"?

I'm expanding your point, not criticizing it.
So sure, Wizards would be cool, but that's hardly the base case. Yeah, stacking stuff like Auras and Bless and whatever are nice, but the fact is that Int is usually a dump stat for non-Wizards and a DC 15, unless you have extraordinary and persistent cover, is not a chump save. If you're facing dozens of illithids, the law of averages is going to get you.

[Imbalance]

Take off and nuke the entire site from orbit. It's the only way to be sure.

Is there an Elder Brain running this joint? That's as important a factor as the number of 'thids, because at some point you may have to admit you're playing Metroid and you'll have to give the players phazon beams or something.

[MaxWilson]

Take off and nuke the entire site from orbit. It's the only way to be sure.

This installation has a substantial gold piece value though.

[Imbalance]

This installation has a substantial gold piece value though.

They can bill me.

[NNescio]

The main issue is the Elder Brain's Creature Sense ability, which acts as a potent anti-intrusion system (unless there's a lot of unaccounted-for noise in the background , which is unlikely.) The first search party sent out to investigate will likely be easily-surmountable by the party, but after the Elder Brain is aware of the threat it can pretty much coordinate the entire colony against the party in a ridiculously efficient manner, like someone playing an RTS from a top-down perspective. Things get worse if one of the party (or a minion/pet) gets incapped (sleeping or getting stunned counts), allowing the Elder Brain to link to it and see through its eyes.

So, at minimum, every member of the party need to have Nondetection up. Minions too, except for those that can be tucked away in extradimensional space (a familiar hiding in a pocket dimension provides very good distraction when needed). Ideally you want Mind Blank but this is only available at L15, plus spell slots are limited.

After that, you want some way to shield against charm (and by extension Dominate) effects. Protection from Evil and Good is the usual standby, but you can't have it active all the time. The Archfey Paladin's Aura of Devotion is also nice, but relying solely on it can be risky because it forces the party into a certain formation. Calm Emotions will work nicely to temporarily suppress Charm effects so your party member can do its thing. Meanwhile Dispel Evil and Good and Greater Restoration can outright remove Charm effects. (but they are costly in spell slots to use.). Some way to boost saves would also be nice, as further insurance; Bless, Bardic Inspiration and the Paladin's aura work well here.

Construct minions are good to have around if you have the wherewithal to acquire them. The simplest way is via True Polymorph'd objects; Helmed Horrors are excellent for this purpose due to their long list of condition immunities. This does require a L17 caster though.

[Brookshw]

They can bill me.

Well played both of you.

Back to the OP, as people have demonstrated there are ways to deal with the mindflayers. What I'm wondering about are the thralls & minions that would also be about. MFs are smart and should keep things around to deal with enemies who are otherwise immune to the MFs. How strong those things are is up to you, but you should consider it carefully before the campaign concludes with the party casting a buff or two then chopping through a bunch of relatively weak squids.

[LudicSavant]

I'm expanding your point, not criticizing it. Ah, I see.

[Willie the Duck]

Thinking about making a campaign focused on taking down a mind-flayer colony
but given that they have dominate monster 1/day for each one, and that they are acting as a hivemind, I really don't see how even a 4 max level party can take a full colony down. Am I missing something or is this truly impossible?


what about mind blast? a full colony of mind blasting creatures will surely be too much even for what you said.

There is nothing in these specific abilities that are specifically bad such that large numbers of them would be inherently more problematic for high-level adventurers than what they otherwise might face. Dominate is even something that PCs can gain temporary actual immunity from. Compare taking on a colony of a few dozen to maybe 50 mind flayers to taking on a colony/city of a several hundred human soldiers and frankly the humans might be more of a problem for a party of 4 level 20 characters. Mind you, at-will area effects are damn frustrating and my general advice is not to do this scenario (or at least expect that it will be solved with out-of-the-box thinking rather than direct confrontation) -- not because it would be impossible for the party, but because the whole thing might become an insufferable quagmire of checking distances and blast radii.

[NNescio]

There is nothing in these specific abilities that are specifically bad such that large numbers of them would be inherently more problematic for high-level adventurers than what they otherwise might face. Dominate is even something that PCs can gain temporary actual immunity from. Compare taking on a colony of a few dozen to maybe 50 mind flayers to taking on a colony/city of a several hundred human soldiers and frankly the humans might be more of a problem for a party of 4 level 20 characters. ...

Planar Bind/True Polymorph something with immunity to nonmagical attacks. Sic it on the human colony while you and your mates sip martinis and watch the spectacle with Scry-Teevo. Cackle evilly all the way.

Or, yannow, just Mirage Arcane the whole place. Or Shapechange/True Poly into a dragon (shadow for added !!FUN!!) and burn down the whole place, if you want to be hands-on for some reason. Remember to have a friend (or Sim) with Dispel if you go with True Poly.

[Grod_The_Giant]

what about mind blast? a full colony of mind blasting creatures will surely be too much even for what you said.
Counterargument: Meteor Swarm has a one-mile range and deals enough damage to one-shot a 'flayer on a successful save.

[nickl_2000]

Counterargument: Meteor Swarm has a one-mile range and deals enough damage to one-shot a 'flayer on a successful save.

Does Meteor Swarm work underground?

[Tharkun]

A wizard with time to prep can set up multiple glyphs of warding that cast mind blank in a demiplane. That solves all of the domination/psychic damage issues.

Wizards and Paladins are very useful in this circumstance. This could be a blast to do. Someone might die in the end but I see the colony going down.

[Tharkun]

Does Meteor Swarm work underground?

Yes.


Blazing orbs of fire plummet to the ground at four different points you can see within range. Each creature in a 40-foot-radius sphere centered on each point you choose must make a Dexterity saving throw. The sphere spreads around corners. A creature takes 20d6 fire damage and 20d6 bludgeoning damage on a failed save, or half as much damage on a successful one. A creature in the area of more than one fiery burst is affected only once.

The spell damages objects in the area and ignites flammable objects that aren't being worn or carried.

[NNescio]

Yes.


Blazing orbs of fire plummet to the ground at four different points you can see within range. Each creature in a 40-foot-radius sphere centered on each point you choose must make a Dexterity saving throw. The sphere spreads around corners. A creature takes 20d6 fire damage and 20d6 bludgeoning damage on a failed save, or half as much damage on a successful one. A creature in the area of more than one fiery burst is affected only once.

The spell damages objects in the area and ignites flammable objects that aren't being worn or carried.

It does, but it's not going to be very useful underground unless there's one big cavern where all the squidfaces congregate for some reason.

Maybe the party can scout out the place and bait all of them into a convenient location, but that's a dicey proposition.

[Willie the Duck]

Does Meteor Swarm work underground?

AFAICT, nothing in the spell description precludes it.


Planar Bind/True Polymorph something with immunity to nonmagical attacks. Sic it on the human colony while you and your mates sip martinis and watch the spectacle with Scry-Teevo. Cackle evilly all the way.

Swap out immunity to nonmagical attacks with immunity to psychic abilities, and you've just solved the illithid problem, so I don't really think that changes the illithid vs. human colony math. Regardless, I'd put that in the out-of-box strategies I'd expect to see in these scenarios. It is really the...


Or, yannow, just Mirage Arcane the whole place. Or Shapechange/True Poly into a dragon (shadow for added !!FUN!!) and burn down the whole place, if you want to be hands-on for some reason. Remember to have a friend (or Sim) with Dispel if you go with True Poly.

...hands-on scenario like this that I think the OP was talking about (given that he was worried about the illithids' dominates and mind blasts).

[MaxWilson]

Planar Bind/True Polymorph something with immunity to nonmagical attacks. Sic it on the human colony while you and your mates sip martinis and watch the spectacle with Scry-Teevo. Cackle evilly all the way.

Or, yannow, just Mirage Arcane the whole place. Or Shapechange/True Poly into a dragon (shadow for added !!FUN!!) and burn down the whole place, if you want to be hands-on for some reason. Remember to have a friend (or Sim) with Dispel if you go with True Poly.

Dispel is not needed--attacking yourself until you hit 0 HP does the same thing.



...hands-on scenario like this that I think the OP was talking about (given that he was worried about the illithids' dominates and mind blasts).

Covered by Mind Blank, Int save proficiency (with Shapechange at least), and legendary resistances (unlike legendary active you do get these when Shapechanging), plus you don't have to end your turns in Mind Blast range because you fly 80' and have reach weapons.

What I'd be most worried about in this scenario is a thrall or mind flayer arcanist with Dispel Magic. There goes Shapechange, there goes Mind Blank, now you have to teleport away or it's Welcome To the Collective.

[NNescio]

Swap out immunity to nonmagical attacks with immunity to psychic abilities, and you've just solved the illithid problem, so I don't really think that changes the illithid vs. human colony math.

Illithids probably have thralls and other contingencies to deal with psy-immune enemies. It's still a useful tactic, but the party will still have to hang around to provide some supervision (and deal with those contingencies). There are much more resourceful than the typical human colony or city (unless said city is filled with high-level casters).

It's also harder to find something that is completely immune to illithids. Most constructs can still be rendered harmless with Levitate. Helmed Horrors are susceptible to psychic damage, and Flying Swords, while completely immune, are kinda lackluster in combat. They are nice to have around, but again the party would probably still need to stick around to supervise.




Regardless, I'd put that in the out-of-box strategies I'd expect to see in these scenarios. It is really the...



...hands-on scenario like this that I think the OP was talking about (given that he was worried about the illithids' dominates and mind blasts).

Illithids live underground and have a lot of early-warning detection defenses. This makes hands-off approaches much harder (other than, well, bribing a large enough Githyanki death squad).

Human colonies, on the other hand, are usually found on the surface and can be easily bombarded from a distance.

Edit:
Covered by Mind Blank, Int save proficiency (with Shapechange at least), and legendary resistances (unlike legendary active you do get these when Shapechanging), plus you don't have to end your turns in Mind Blast range because you fly 80' and have reach weapons.

What I'd be most worried about in this scenario is a thrall or mind flayer arcanist with Dispel Magic. There goes Shapechange, there goes Mind Blank, now you have to teleport away or it's Welcome To the Collective.

Send a True Poly'd Sim (or Shapechange for spell access, but concentration to maintain is riskier) then, along with True Poly'd Helmed Horror minions, plus the entire party behind an Astral Projection (with Mind Blank or Non-Detection)?

[darknite]

FYI - Mind Blank prevents psychic damage but will not keep you from being stunned by a Mind Blast.

[Damon_Tor]

AFAICT, nothing in the spell description precludes it.

It says they "plummet to the ground." Ergo, anything under the ground isn't likely to be effected.

[darknite]

It says they "plummet to the ground." Ergo, anything under the ground isn't likely to be effected.

Unless there's more ground under ground to plummet to?

[Willie the Duck]

<SNIP>

We can play contingency bingo until we are all sufficiently bored (and honestly this is already starting to sound like a Batman v. Superman debate where any point will be countered with 'Batman will be prepared for that'). Of course Illithid have thralls that need to be taken into account (and why the PCs will have gathered/summoned allies, which is why it is never really just 4 20th-level characters vs. anything). Likewise, cities probably have mages on top of the massed archers along the walls I was mostly thinking about. My only real point in using the human city is that I can readily see 4 20th-level characters each having an answer to dominate monster and mind blast, but still all but the guy shapechanged into a immune-to-normal-weapons monster still being able to be taken down by sufficient arrows. It was not a rigorous analysis and I'm unsurprised casual examination can find a bunch of weak points.

Here is my main point: I am guessing that the OP recently ran into multiple illithids at moderate level. My own group had a similar situation recently where we ran into 4-6 beholders when we were 11-12th level. It was indeed brutal. Being subjected to massively multiple save effects (yes many of them 'merely damage' but man does that not help when you get 60%+ of your hp taken out in one bad round). I can easily imagine someone thinking 'scale up the number appearing on this a few times and it's impossible. I don't care what level you are' I think that's a reasonable impression to get, but that in the end it is more hopeful for the high-level characters than this initial impression suggests. Particularly with illithids, because a whole lot of their abilities fall under the same category of with regards to what defenses work best against them. Also simply because of the difference between the mid-level play where 1-2 illithids/beholders are a reasonable opponent (and where 4-6 really sucks) and 20th level, where a lot of the strategy changes. Gate, Shapechange, legendary resistances, being able to get all or most of the party covered by Mind Blank -- these are things which can turn massively multiple dominate attempts and at-will area effect psychic damage from 'this is impossible' to 'well, we better not screw this up, but it is definitely doable.'


It says they "plummet to the ground." Ergo, anything under the ground isn't likely to be effected.

There is definitely a grey area about what 'ground' is, but the spell has no specified requirements about being outside or having a specific amount of ground (or 'ground') clearance in the way that spells like Call Lightning have.

[Ventruenox]

In my current game as a player, we are approaching the end of the campaign (3 sessions remaining). We have just learned that the Mind Flayers have infiltrated a large number of the populace, and have certainly dominated major NPCs that hold the political power.

I'm considering an unconventional approach to the problem: joining them. My character's main goal is peddling a pyramid scheme fake religion, with an emphasis that memories can be retained in your next life. Utilizing the Illithid collective may be able to do just that. I can propose that they continue their spread with the phony religion as a viable cover for their actions. I could also probably get some DM buy in to this if I utilize a cursed object I've had since the start of the campaign to disrupt the ceremorphosis, then go Hugh Borg (https://memory-alpha.fandom.com/wiki/Hugh) on the collective.

It would be interesting, if nothing else, to be able to bypass the BBEG battle with a Persuasion roll. Mechanically, I know I can squeeze out somewhere between +12-20 with advantage on my roll. I doubt the other players' characters would be down with this, but I can see the players themselves finding it entertaining.

[nickl_2000]

It says they "plummet to the ground." Ergo, anything under the ground isn't likely to be effected.


Unless there's more ground under ground to plummet to?

The reason I asked was due to spells like Call Lightning (need to see the sky or have certain feet tall room) and my experience with level 9 spells is extremely low. There is nothing in it spelled out like that, so that was all I needed :smallbiggrin:

[Brookshw]

Unless there's more ground under ground to plummet to?

Sounds like some strange line of effect rules.

Even if usable underground, range of sight seems to remain an issue.

[darknite]

Sounds like some strange line of effect rules.

Even if usable underground, range of sight seems to remain an issue.

There is absolutely nothing in the spell description that limits Meteor Swarm to an outdoor location. It works really well in an outdoor location because of Range = 1 mile and the ability to spread areas of effect. But nothing says it can't be used to some degree in a subterranean environment.

[Tharkun]

FYI - Mind Blank prevents psychic damage but will not keep you from being stunned by a Mind Blast.
You are correct but a wizard will have no trouble given max int and any saving throw boosts and the Paladin makes it pretty easy for the rest of the party given some prep.

[darknite]

You are correct but a wizard will have no trouble given max int and any saving throw boosts and the Paladin makes it pretty easy for the rest of the party given some prep.

Definitely a good strategy. Really depends on the extent of threat you're facing, the makeup of your party and the resources they have. I play plenty of high level games and illithids are still plenty scary, even in small numbers, especially when the best laid plans make contact with an enemy hivemind.

[Aprender]

Does anyone know the story of how Hercules cleaned the royal stables? He diverted a river rather than attempt the impossible task of cleaning the stalls individually.

Remember how much better your combat got when you started using the surrounding environment to improve your tactics? (I push him off the cliff!)

All of the above points are valid (and I love the Aliens references), but I want to throw out there that 20th level characters can and should be epic. They can affect gods and nature alike.

If there is a mind flayers base underground, flood it.... With lava.

Drop a mountain on the above ground citadel of mindflayers.

The Gith would gladly push the planet into the sun to rid the universe of a large Colony. Dial it back a notch, and you've got the start of a plan.

[Dork_Forge]

It really depends on the number of Illithids, number of thralls (and type), whether there is an Elder Brain and or a Ulitharid.

Realistically yes it's possible, by the time a party is 20th level they would have amassed a large amount treasure and allies to compliment their array of powers but it would be (and should be) very difficult. If the party doesn't have a Wizard or Paladin then it'll be harder, so it also depends on if the party are building for this.

If this was just theorycrafting then the answer is probably just yes, PCs have access to very powerful abilities and effects at 20th level, with the treasure and sway to bring to bear reinforcements. If you were considering running a game like this then just throw together a one shot, let the players know ahead of time that they'll be going after a colony to exterminate it and see how it goes, it'll be fun win or lose!

Sounds like a fun thing to try and a place where a GOO Warlock can really shine.

[Tharkun]

Definitely a good strategy. Really depends on the extent of threat you're facing, the makeup of your party and the resources they have. I play plenty of high level games and illithids are still plenty scary, even in small numbers, especially when the best laid plans make contact with an enemy hivemind.

Truth. I was in a level 1 party that saw an Illithid and I nearly died IRL. As a DM I would do quite a bit to make this hard. Multiple Mind Blasts are really brutal and there is so much crazy that is possible

[Damon_Tor]

Unless there's more ground under ground to plummet to?

There's a language problem here: ground has two different meanings.


Ground, noun
1. the solid surface of the earth; firm or dry land:
to fall to the ground.
2. earth or soil:
stony ground.

One is the definition I had used: it refers to the surface of the Earth (or, one presumes, any other planet). The other is the one you appear to be using.

This means RAW is unclear, which means we need to determine RAI. I think it's pretty clear the spell is intended to summon meteors (hence the name of the spell), which by definition fall from the sky. With that in mind we can infer that the designers intended the word "ground" in the sense of the first definition, not the second.

[dreast]

but the fact is that Int is usually a dump stat for non-Wizards and a DC 15, unless you have extraordinary and persistent cover, is not a chump save. If you're facing dozens of illithids, the law of averages is going to get you.

“Mind flayers suck.”

“Why?”

“They have powerful abilities that target a dump stat.”

“Why is it a dump stat?”

“Because only one class really uses it, and not much requires you to save with it. I wish they targeted Wisdom instead.”

“Well, maybe this has something to do with the fact that they are a legacy monster, and stat based saves weren’t really a thing. Perhaps we should look at what they did in AD&D 2e. Were they more fun to fight there?”

“Oh heck no! They could destroy people because they targeted a dump stat and if you ran out, it was instant death!”

“Why was it a dump stat?”

“Because only one class really used it, and not much else targeted it.”

“Well, at least they’re consistent. Maybe the answer should be that more creatures target Intelligence?”

“No way!”

“Why not?”

“Because then we couldn’t use it as a dump stat!”

[Protolisk]

There's a language problem here: ground has two different meanings.


Ground, noun
1. the solid surface of the earth; firm or dry land:
to fall to the ground.
2. earth or soil:
stony ground.

One is the definition I had used: it refers to the surface of the Earth (or, one presumes, any other planet). The other is the one you appear to be using.

This means RAW is unclear, which means we need to determine RAI. I think it's pretty clear the spell is intended to summon meteors (hence the name of the spell), which by definition fall from the sky. With that in mind we can infer that the designers intended the word "ground" in the sense of the first definition, not the second.

Meteor swarm just says blazing orbs of fire plummet to the ground. No explicit statement of coming from the sky, or not working indoors. Not even saying the actual size of those orbs, so they could be beads like Fireball, technically. Small beads falling 1 inch is still plummeting as long as it goes fast, as plummeting is just falling fast. Considering we can literally transpose matter and disrupt space, affecting how fast our newly summoned matter is going is hardly a challenge.

Either of your definitions can still mean earth as in dirt or rock, not explicitly a planet. Inviting that it needs to be "earth" the planet could mean that it won't work on Eberron or Toril, etc., but that is really nebulous and I won't go down that line of arguments.

You can deduce that the way it is written implies the spell must be from the sky, but if they really wanted that effect they would have done the same thing Call Lightning says, with specific heights and spell failure if there isn't enough space for a storm cloud. It doesn't, so it doesn't. Spells only do what they say they do and don't do what they say they don't do, so Meteor Swarm can summon blazing orbs that fall quickly, but not explicitly from the sky. Underground Meteor Swarm is viable.

Now, since underground areas tend to be tunnels and small caverns, and you need to see the points you are designating, good luck not catching yourself in the massive area of effect.

[MaxWilson]

Now, since underground areas tend to be tunnels and small caverns, and you need to see the points you are designating, good luck not catching yourself in the massive area of effect.

Hmmm, I wonder if Contingency: Dimension Door could help you out there.

"When: blazing orbs of fire fall from the sky or I am reduced to less than 30 HP, Then: Dimension Door me 500' straight up (and I'll Feather Fall down)."

Does the fire from a Meteor Swarm expand faster than a Contingent spell can trigger? Inquiring minds want to know, probably through experimentation.

[Zuras]

Come on people, you’re not even trying. A 13th level Cleric can use Conjure Celestial to get a Couatl, which is conveniently immune to non-magical weapons and psychic damage.

[MaxWilson]

Come on people, you’re not even trying. A 13th level Cleric can use Conjure Celestial to get a Couatl, which is conveniently immune to non-magical weapons and psychic damage.

But not, however, to Dispel Magic. It's still a conjured creature.

Nor is it immune to Plane Shift, or being stunned by a Mind Flayer's tentacle attack, or Dominate Monster.

[Lunali]

This, right here. That's why the party accumulated all of that treasure ... to offer the Gith a bit of coin for the raid.

That's just bad treasure management, you don't pay the gith to raid mind flayers, you charge them for it.

[MaxWilson]

That's just bad treasure management, you don't pay the gith to raid mind flayers, you charge them for it.

Well-played!

[sithlordnergal]

Honestly? No, it isn't. You would need to be a higher level, but I could see a group of level 12 to 13 PCs surviving a mind flayer colony. As for extinguishing it, a level 20 party that is reasonably optimized should be able to do it with ease. Just off the top of my head, a party with a Wizard, Rogue, Cleric, and Paladin with max charisma should be able to handle it.

[Protolisk]

Come on people, you’re not even trying. A 13th level Cleric can use Conjure Celestial to get a Couatl, which is conveniently immune to non-magical weapons and psychic damage.

This is a great option too. All the initial question asked was if max level characters could do it. I think the general view is "yes, they can". Moving the goalpost to "how low a level can you go" is not what was asked, but it is definitely fun to think about. Then again, most answers are about level 9 spells, so full casters by level 17 could manage it.

A level 10 Great Old One warlock would have resistance to psychic damage, but also reflects that damage back on the attacker. No illithid is actually resistant or immune to psychic damage, so with enough healing a GOOlock could figure something out. The stunning effects of Mind Blast would still need to be contended with...

Mind blast itself is a "magical" effect. So gnomes could get advantage against Mind Blast from level 1, as well as the Dominate spells. Helps that all gnomes get +2 to Int off the bat to help with saves against Mind Blast. Get yourself some level 10 gnome GOOlocks and head on down to Mind Flayer town. They are still warlocks, so darkness could be abused against the mind flayers that have mind blast on cooldown, since Mind Flayers can't perceive the gnomes. An Elderbrain could, though, but a Mind Blast needs to be successful for their funky abilities to work well. Need to get within 60 feet of the gnome squad to stun-incapacitate them. Too bad the actual spells in most Mind Flayer's repertoire requires sight, because again, Magical Darkness. A squad of Gnomes could stagger their Darkness casts so that they aren't completely incapped by an errant mind blast.

If gnomes abuse Eldritch Blast and the pushing abilities from invocations, they could keep them at bay. And with Devil's Sight, the gnomes and mind flayers should see each other at the same distance, but the gnomes have magical darkness on their side so it's kind of moot anyway. Just hope that your combats take place in at least 90 foot areas so you have enough space to knock the flayers back, lest they walk 30 feet forward and then catch you in a 60 foot cone.

If level 10s could cheese this, higher levels should be able to as well. Of course, the flayers' minions might screw with these tactics, as well as plain old un/luckiness, but this is a workable plan. It's not absolute cheese like Couatl summoning, but it can hold its own.

[MaxWilson]

This is a great option too. All the initial question asked was if max level characters could do it. I think the general view is "yes, they can". Moving the goalpost to "how low a level can you go" is not what was asked, but it is definitely fun to think about. Then again, most answers are about level 9 spells, so full casters by level 17 could manage it.

A level 10 Great Old One warlock would have resistance to psychic damage, but also reflects that damage back on the attacker. No illithid is actually resistant or immune to psychic damage, so with enough healing a GOOlock could figure something out. The stunning effects of Mind Blast would still need to be contended with...

Mind blast itself is a "magical" effect. So gnomes could get advantage against Mind Blast from level 1, as well as the Dominate spells. Helps that all gnomes get +2 to Int off the bat to help with saves against Mind Blast. Get yourself some level 10 gnome GOOlocks and head on down to Mind Flayer town. They are still warlocks, so darkness could be abused against the mind flayers that have mind blast on cooldown, since Mind Flayers can't perceive the gnomes. An Elderbrain could, though, but a Mind Blast needs to be successful for their funky abilities to work well. Need to get within 60 feet of the gnome squad to stun-incapacitate them. Too bad the actual spells in most Mind Flayer's repertoire requires sight, because again, Magical Darkness. A squad of Gnomes could stagger their Darkness casts so that they aren't completely incapped by an errant mind blast.

If gnomes abuse Eldritch Blast and the pushing abilities from invocations, they could keep them at bay. And with Devil's Sight, the gnomes and mind flayers should see each other at the same distance, but the gnomes have magical darkness on their side so it's kind of moot anyway. Just hope that your combats take place in at least 90 foot areas so you have enough space to knock the flayers back, lest they walk 30 feet forward and then catch you in a 60 foot cone.

If level 10s could cheese this, higher levels should be able to as well. Of course, the flayers' minions might screw with these tactics, as well as plain old un/luckiness, but this is a workable plan. It's not absolute cheese like Couatl summoning, but it can hold its own.

How many Mind Flayers are you envisioning in this "how low can you go" challenge? (Agonizing Repelling) Eldritch Blast won't keep more than a handful of mind flayers at bay, for instance. Won't work on even as many as a dozen mind flayers.

In theory you could wipe out the whole colony with a level 8 Orcish Rogue 2/Shadow Monk 6, as long as you've rolled a 3 on Int. After Orc penalties, your Int is too low for Intellect Devourers and Elder Brains to detect your presence, so you can abuse the Cunning Action (Hide) + Skulker + Pass Without Trace combo to surprise and then basically pick off Mind Flayers and/or thralls whenever they're isolated from the main body, using your surprise round/martial arts/stunning strike. Every two hours you withdraw and take a short rest to regain ki, then do it again. You're basically Pennywise the Dancing Clown terrorizing the illithid Derry. Might take you several weeks to completely depopulate the colony but you've got plenty of time.

From a RP angle, though, it's very implausible that an Int 1 Orc would ever actually invent such tactics, or be motivated to wipe out a mind flayer colony in the first place.

[Protolisk]

How many Mind Flayers are you envisioning in this "how low can you go" challenge? (Agonizing Repelling) Eldritch Blast won't keep more than a handful of mind flayers at bay, for instance. Won't work on even as many as a dozen mind flayers.

In theory you could wipe out the whole colony with a level 8 Orcish Rogue 2/Shadow Monk 6, as long as you've rolled a 3 on Int. After Orc penalties, your Int is too low for Intellect Devourers and Elder Brains to detect your presence, so you can abuse the Cunning Action (Hide) + Skulker + Pass Without Trace combo to surprise and then basically pick off Mind Flayers and/or thralls whenever they're isolated from the main body, using your surprise round/martial arts/stunning strike. Every two hours you withdraw and take a short rest to regain ki, then do it again. You're basically Pennywise the Dancing Clown terrorizing the illithid Derry. Might take you several weeks to completely depopulate the colony but you've got plenty of time.

From a RP angle, though, it's very implausible that an Int 1 Orc would ever actually invent such tactics, or be motivated to wipe out a mind flayer colony in the first place.

I was mostly thinking tunnels. If they kept to tunnels that are only wide enough for a few at a time 4 gnomes can do 8 attacks at advantage and knock the flayers back a lot. Works for 2-3 or so flayers at a time. Level 11 gets up to 12 attacks per turn. Too open of areas does make it worse. You idea of working around 1 int is pretty hilarious, not gonna lie.

[MaxWilson]

I was mostly thinking tunnels. If they kept to tunnels that are only wide enough for a few at a time 4 gnomes can do 8 attacks at advantage and knock the flayers back a lot. Works for 2-3 or so flayers at a time. Level 11 gets up to 12 attacks per turn. Too open of areas does make it worse. You idea of working around 1 int is pretty hilarious, not gonna lie.

Don't the mind flayers just back off around a corner until your Darkness spell slots run out?

[Protolisk]

Don't the mind flayers just back off around a corner until your Darkness spell slots run out?

Then you just approach the corner and then start blasting them again. They still can't see you, so attacking blind is useless. And full cover blocks Mind blast as it doesn't ignore cover like Fireball does. So a single gnome might get hit, but not all of them. Continue blasting and hoping to knock them back further still, but yeah it breaks down. But again, resistant to psychic and advantage against the saves.

Like I said it's not perfect, but it is workable. If level 10s have a reasonable plan, then max levels should be able to do it no sweat.

[JackPhoenix]

Taking out the Elder Brain is crucial, as it is the centerpiece of any mind flayer colony. It also screws up mind flayer warning system.


Funnily enough, Elder Brain needs to breathe, and lacks amphibious trait. You can use that in multiple ways, burying it in rock with Earthquake or Transmute Rock, or even drowning it. It can Plane Shift, but only once per day, PS is inaccurate, and the brain can't survive long outside its brine pool.


Steel Predator is immune to psychic damage and stunned and charmed conditions. Also to non-magical physical attacks of any minions mind flayers may have. It's too big to be grappled by mind flayer tentacles. While it's Int of 4 is too high to be invisible to Elder Brain, it'll propably get ignored for at least a while, and you can always slap Nondetection on it. And you can buy (or rather hire) those things in Sigil.

Get a sample from the brine pool to mark the Elder Brain as target, and release the hounds.


Another alternative is True Polymorphing someone into a demilich. Same crucial immunities as Steel Predator. It also has Legendary Resistance in case the mind flayers try some other trick. Then there's the fun part: Howl has 65% (It's not magical so no advantage due to magic resistance of dropping any mindflayer in 30' radius to 0 hp. It's neither spell nor attack, so it doesn't break invisibility. Imagine invisible screaming skull flying through the colony, killing everything around itself. Too bad it's undead, so you can't use Shapechange instead of True Polymorph to retain your class abilities.

[MaxWilson]

Then you just approach the corner and then start blasting them again. They still can't see you, so attacking blind is useless.

When you turn the corner, you get hit with a bunch of readied Mind Blasts from prone Mind Flayers. All you've done is chase them until the terrain favors them more than you. This plan seems like a recipe for suicide even if the mind flayers DON'T do anything tricky like envelope you or mousetrap you.

[NNescio]

In theory you could wipe out the whole colony with a level 8 Orcish Rogue 2/Shadow Monk 6, as long as you've rolled a 3 on Int. After Orc penalties, your Int is too low for Intellect Devourers and Elder Brains to detect your presence, so you can abuse the Cunning Action (Hide) + Skulker + Pass Without Trace combo to surprise and then basically pick off Mind Flayers and/or thralls whenever they're isolated from the main body, using your surprise round/martial arts/stunning strike. Every two hours you withdraw and take a short rest to regain ki, then do it again. You're basically Pennywise the Dancing Clown terrorizing the illithid Derry. Might take you several weeks to completely depopulate the colony but you've got plenty of time.

From a RP angle, though, it's very implausible that an Int 1 Orc would ever actually invent such tactics, or be motivated to wipe out a mind flayer colony in the first place.

He's an escaped subject from an Illithid bioweapons research project?

[sithlordnergal]

When you turn the corner, you get hit with a bunch of readied Mind Blasts from prone Mind Flayers. All you've done is chase them until the terrain favors them more than you. This plan seems like a recipe for suicide even if the mind flayers DON'T do anything tricky like envelope you or mousetrap you.

I mean, as long as you have a decent Int save at level 20 then you're fine. A Wizard 18/Hexblade Warlock 2 should be able to handle it with ease. If you're level 20, you should have been able to find some powerful items by then, so a Staff of Power and Ring of Protection is within reason. Cast a single Mind Blank on yourself and congrats, you are now immune to the Mind Blasts cause you'll have an Int save of +14, so even if you roll a 1 you will make the save

Ahh, but how about parties without a staff? May I introduce the Paladin with Bless. If they're a good Paladin, they will have taken 20 Charisma, and hopefully snagged Warlock or Sorcerer levels. Remain within the aura as you go around corners for a handy +5 to all saves. Now you don't need items, just Mind Blank.

[Dork_Forge]

I mean, as long as you have a decent Int save at level 20 then you're fine. A Wizard 18/Hexblade Warlock 2 should be able to handle it with ease. If you're level 20, you should have been able to find some powerful items by then, so a Staff of Power and Ring of Protection is within reason. Cast a single Mind Blank on yourself and congrats, you are now immune to the Mind Blasts cause you'll have an Int save of +14, so even if you roll a 1 you will make the save

Ahh, but how about parties without a staff? May I introduce the Paladin with Bless. If they're a good Paladin, they will have taken 20 Charisma, and hopefully snagged Warlock or Sorcerer levels. Remain within the aura as you go around corners for a handy +5 to all saves. Now you don't need items, just Mind Blank.

That seems good for the Wizard, but other characters won't have the luxury of a +5 Int, and you only have to fail once to be stunned, regardless of Mind Blank.

Separately though, would Mind Blank protect against the Elder Brain's mind link ability? It seems possible it would but I'm not sure.

[ProsecutorGodot]

If our 14th level party (Paladin, Monk, EK/Wiz, Sorcerer) in Dungeon of the Mad Mage made quick work of an upstart colony of Mind Flayers (roughly a dozen Mind Flayers and an Ulitharid) and a Neothelid then I'm sure a specially prepared force could kill many times that. I (the paladin) only stayed stunned for 3 consecutive turns at the entrance, it wasn't that big a deal since my Aura of Protection still functioned.

Granted this was a relatively small and struggling colony but our success only sets precedent for other more capable groups to do the same.

We brought the Ulitharid head home, had it magically preserved and put it up as a centerpiece in our tavern. Durnan makes sure people never forget that we saved the city from a potential Illithid incursion and we have the proof hung up on the wall, tavern cross promotion strategy.

[MaxWilson]

I mean, as long as you have a decent Int save at level 20 then you're fine.

I was talking about the party of 11th level Repelling Blast GOOlocks, not the max-level party.

[sithlordnergal]

That seems good for the Wizard, but other characters won't have the luxury of a +5 Int, and you only have to fail once to be stunned, regardless of Mind Blank.

Separately though, would Mind Blank protect against the Elder Brain's mind link ability? It seems possible it would but I'm not sure.

It should work, since Mind Blank prevents even Wish spells and spell effects from working. And that is why you go with a mostly Wizard team, or have everyone start as a Wizard and put 14 into your Int at the very least. The Paladin should be fine with a 16 Strength if they have a +3 weapon, which at level 20 they should. Even if they don't Mind Flayers only have a 15 AC, so you should be able to consistently hit one with +3 strength and your proficiency bonus. Just make sure you have Bless up, and bam, you can't roll below a 15.

[Brookshw]

"When: blazing orbs of fire fall from the sky or I am reduced to less than 30 HP, Then: Dimension Door me 500' straight up (and I'll Feather Fall down)."


Quibble, you only get one condition on a contingency, the "or" portion has to go,/quibble.

[nickl_2000]

That's just bad treasure management, you don't pay the gith to raid mind flayers, you charge them for it.

I was originally thinking to just tell them about it. Considering the hatred of mine flayer by gith, it would be enough. However, swelling them the location seems like a decent plan too.

[NNescio]

I was originally thinking to just tell them about it. Considering the hatred of mine flayer by gith, it would be enough. However, swelling them the location seems like a decent plan too.

More trustworthy too! Telling them for free or paying them to raid just sounds fishy, like you're in cahoots with the squiddies to lure them into a trap (heh).

[Protolisk]

When you turn the corner, you get hit with a bunch of readied Mind Blasts from prone Mind Flayers. All you've done is chase them until the terrain favors them more than you. This plan seems like a recipe for suicide even if the mind flayers DON'T do anything tricky like envelope you or mousetrap you.

Darn, I forgot warlocks know Eldritch Blast and only Eldritch Blast. :smallbiggrin:

If the mind flayers are prone,

1. It's not for too much defense against Eldritch Blast, as it's neither disadvantage or advantage while the gnomes are in Darkness, so they have reasonable chances to hit still. Mind flayers have 15 AC while wearing a breastplate, they aren't that hard to hit by a mid level warlock.

2. The warlocks don't need straight attacks. Nabbing them with choice Dex save cantrip or spell would still do the job if they ended up at disadvantage entirely for their Eldrtich Blast. Mind Flayers have a pitiful Dex save. Honestly, it might be even stronger this way.

3. If our squidly friends are prone to dodge each others Mind Blasts, then a prone gnome dodges it too. Cones don't curve around the prone allies. What a waste.

4. If the mid flayers are going to Mind Blast through their allies... then their allies are getting hit by Mind Blast too. Free damage and control for our side.

5. Readied actions need a good trigger. If the trigger was "when I see magical darkness" then they just missed all their blasts, because the gnome can be behind cover the second the flayers see the darkness as it has a radius. If the trigger is "we see Eldritch Blasts", then the warlocks could just not use it. If it was "When anything dangerous happens to out side", the safest option, then our gnomes should probably work around this as it is the safest bet, and the one the mind flayers likely chose.

6. Wall of Light is a 5th level spell warlocks can know. If the tunnels are still cramped, then a gnome can stand 10 or so feet back from the corner, designate that point at the corner for the wall, and then send it 60 feet down the tunnel. Since the gnomes are still behind their cover, any flayers' that are caught outside will mind blast on zero targets.

7. Even more, prone mind flayers can get caught in a choice Evard's Black Tentacles on the Goolocks list and now will have a hard time getting out. You mention a "bunch" of readied blasts, so I assume there are a bunch in a group. This compounds the issues I said above, but additionally this is where AoE shines supreme.

8. Even with just +1 to the save (base 10, gnomes add +2), they are making the Mind Blast save 57.75% of the time due to advantage. Resilient (Int) would make that an easy +5 to the save for a 79.75. If they put any additional points it becomes harder and harder to make the gnomes actually lose the save. For comparison, Mind Flayers themselves only make the save about 65% of the time.

Before you even say "well how would the gnomes know the layout", warlocks could have Scrying by now. If they met anyone they know is a mind flayer or servant of one, they could scry them. If this feels like a stretch, then why does your party even know there is a colony? I guess they could have killed all of the people they met so far, but then they have no idea where it is. Suffice to say, if they know about the colony, they probably know someone IN the colony, opponent or prisoner. Once they see one target and see any other target, they "should" know the next target "first hand" to make more scrying checks. With enough scrying, and they could know large areas of the colony easily. They could do this hours before and and get a good layout of the area, and then short rest and get their slots back.

Once they know the area, they could plan their attack more carefully, figure out choke points and so on.

Yadda yadda yadda. I could keep going, but I won't. We could both play a hypothetical game of DnD back and forth, but the base fact of the matter is: players can be crafty. I am coming up with ideas that run on a single subclass of a single class made up entirely of the same race, and of that class all I have used so far is 1 specific cantrip, 2 invocations (repelling and Devil's Sight), and named a total of 4 spells (darkness, Wall of Light, Evard's Black Tentacles, and Scrying). I have neglected to mention any pact boons, the other of their 4 total cantrips, 10 spells known, and 5 invocations. Each one has many options they could go with. Once you add in multiclassing, different classes, different races, and so on, you open up multitudes of new tactics and ideas. This is all not even accounting for any magical items or any context in the campaign that would allow for more interesting solutions (no mind flayer as written is amphibious, so flood the place. Destroy entrance tunnels, starve them. REALLY seal the tunnels, asphyxiate them or just collapse them under rock. They have plane shift, so they probably won't be held off for long for some of these, but you can remove them from this location at least.) Even so, even the best laid plans can be ruined by random chance in D&D, an errant crit or a 1 on a save can be disastrous, but fortune could make it way easier if the dice roll badly for the other side.

And when the original question was "hey, could a max level party do it?" then I hope by now the point is proven: Yes. They certainly can.

[MaxWilson]

Darn, I forgot warlocks know Eldritch Blast and only Eldritch Blast. :smallbiggrin:

If the mind flayers are prone,

1. It's not for too much defense against Eldritch Blast, as it's neither disadvantage or advantage while the gnomes are in Darkness, so they have reasonable chances to hit still. Mind flayers have 15 AC while wearing a breastplate, they aren't that hard to hit by a mid level warlock.

It still negates your advantage, so you hit 75% of the time instead of 94%, and it costs the Mind Flayers nothing (they've got readied Mind Blasts, not readied Attacks, so they might as well), so you can expect them to do it.


2. The warlocks don't need straight attacks. Nabbing them with choice Dex save cantrip or spell would still do the job if they ended up at disadvantage entirely for their Eldrtich Blast. Mind Flayers have a pitiful Dex save. Honestly, it might be even stronger this way.

Re-read the Prone condition. Prone does not affect Dex saves. Mind Flayers will be saving at +1, with advantage for Magic Resistance.


3. If our squidly friends are prone to dodge each others Mind Blasts, then a prone gnome dodges it too. Cones don't curve around the prone allies. What a waste.

It's not clear what you're trying to say here. Let's say gnome crawls around the corner, gets hit with a bunch of readied mind blasts. Assuming Int 16ish, gnomes are saving at +3 (with advantage) against DC 15, so if there's three Mind Flayers that gnome will fail about 1 save, get stunned (losing concentration on Darkness), and take about 10 HP of damage after resistance. How did going prone help the gnome, and what do you mean by "cones don't curve around the prone allies"?


4. If the mid flayers are going to Mind Blast through their allies... then their allies are getting hit by Mind Blast too. Free damage and control for our side.

If they've brought along a bunch of allies, then your Repelling Blast trick isn't even relevant in the first place. I was giving you the benefit of the doubt by assuming no allies.


5. Readied actions need a good trigger. If the trigger was "when I see magical darkness" then they just missed all their blasts, because the gnome can be behind cover the second the flayers see the darkness as it has a radius. If the trigger is "we see Eldritch Blasts", then the warlocks could just not use it. If it was "When anything dangerous happens to out side", the safest option, then our gnomes should probably work around this as it is the safest bet, and the one the mind flayers likely chose.

You don't think Mind Flayers can measure a 15' radius in their own tunnels? I do. Or the Elder Brain could just tell them, "Now!" since it knows exactly where you are at all times.


6. Wall of Light is a 5th level spell warlocks can know. If the tunnels are still cramped, then a gnome can stand 10 or so feet back from the corner, designate that point at the corner for the wall, and then send it 60 feet down the tunnel. Since the gnomes are still behind their cover, any flayers' that are caught outside will mind blast on zero targets.

7. Even more, prone mind flayers can get caught in a choice Evard's Black Tentacles on the Goolocks list and now will have a hard time getting out. You mention a "bunch" of readied blasts, so I assume there are a bunch in a group. This compounds the issues I said above, but additionally this is where AoE shines supreme.

I'm assuming a small number of Mind Flayers for your benefit, because if there are thousands then your plan is obviously totally infeasible and I assume you wouldn't even propose it. I imagine you're imagining about fifty Mind Flayers or less, total. Am I right? And you said before that you're expecting to fight them in groups of 2-3, so you've got to get through 15-20 fights.

Can you beat a group of 3 Mind Flayers with an Evard's Black Tentacles or Wall of Light? Sure, probably. Each time you cast the spell, about half of the Mind Flayers will fail their saves (+1 at advantage vs DC 17ish = 56% chance of failure), and then they'll hit you back, and you'll lose some HP and some spell slots and maybe get a PC's brain eaten. And then you burn more spell slots to keep Darkness up another 10 minutes, and then it's on to the next group of Mind Flayers, 15-20 more times, and that's if the Mind Flayers don't do anything halfway clever like cut off your retreat and envelope you from all sides (with thrall support as meat shields/distractions), or flood the tunnels and drown you.


Before you even say "well how would the gnomes know the layout", warlocks could have Scrying by now.

You don't even need scrying. Just suppose that one of the warlocks is a chainlock. "How would the gnomes know the layout?" is not an objection I would raise, because the answer is obvious.

However, knowing the layout is different from knowing the disposition of enemy forces. The Mind Flayers certainly know where YOU are, and they have excellent command and communication facilities, thanks to the Elder Brain--what you need to worry about is, "If I go into THIS tunnel instead of THAT tunnel, what's going to come out of THAT tunnel and hit me from behind when I'm engaged from the front?"


If they met anyone they know is a mind flayer or servant of one, they could scry them. If this feels like a stretch, then why does your party even know there is a colony? I guess they could have killed all of the people they met so far, but then they have no idea where it is. Suffice to say, if they know about the colony, they probably know someone IN the colony, opponent or prisoner. Once they see one target and see any other target, they "should" know the next target "first hand" to make more scrying checks. With enough scrying, and they could know large areas of the colony easily. They could do this hours before and and get a good layout of the area, and then short rest and get their slots back.

Once they know the area, they could plan their attack more carefully, figure out choke points and so on.

Yadda yadda yadda.

Yadda yadda yadda. Knowing the layout is not a problem, we both know that. Relying on Repelling Blast and psychic damage resistance to stay alive is the problem--those things don't scale well enough to make it safe. Choose a different strategy.


I could keep going, but I won't. We could both play a hypothetical game of DnD back and forth, but the base fact of the matter is: players can be crafty. I am coming up with ideas that run on a single subclass of a single class made up entirely of the same race, and of that class all I have used so far is 1 specific cantrip, 2 invocations (repelling and Devil's Sight), and named a total of 4 spells (darkness, Wall of Light, Evard's Black Tentacles, and Scrying). I have neglected to mention any pact boons, the other of their 4 total cantrips, 10 spells known, and 5 invocations. Each one has many options they could go with. Once you add in multiclassing, different classes, different races, and so on, you open up multitudes of new tactics and ideas. This is all not even accounting for any magical items or any context in the campaign that would allow for more interesting solutions (no mind flayer as written is amphibious, so flood the place. Destroy entrance tunnels, starve them. REALLY seal the tunnels, asphyxiate them or just collapse them under rock. They have plane shift, so they probably won't be held off for long for some of these, but you can remove them from this location at least.) Even so, even the best laid plans can be ruined by random chance in D&D, an errant crit or a 1 on a save can be disastrous, but fortune could make it way easier if the dice roll badly for the other side.

And when the original question was "hey, could a max level party do it?" then I hope by now the point is proven: Yes. They certainly can.

I agree. I'm only critiquing a specific, suboptimal strategy (Repelling Blast warlocking). I'm not saying you can't do it, I'm just saying that is a bad way to do it.

[Protolisk]

I getcha MaxWilson, I didn't explain every little detail of my spiel, so I'll give my reasoning for what I wrote. My main point is that both the mind flayers and the players can pull out weird tricks to stop the other, so it comes down to luck, and a party of level 10s can get fairly far even with few options at their disposal. I just started from Gnome GOOlock because they'd have some innate resistances to what the illithids could dish out. I know it isn't fool proof, because honestly, nothing is. Even Wish could just fail, and Divine Intervention has some limitations.


It still negates your advantage, so you hit 75% of the time instead of 94%, and it costs the Mind Flayers nothing (they've got readied Mind Blasts, not readied Attacks, so they might as well), so you can expect them to do it.

You are right, I forgot about Magic Resistance. Still, advantage with a +1 will fail a reasonable amount of times to a spell save of around 15 compared to neutral Eldritch Blasts as a AC of 15 is the warlocks spell attack bonus of at least 7. Just saying there are more options that could work. I wasn't even maxing out their charsima, but doing that puts either combat option boosted.


Re-read the Prone condition. Prone does not affect Dex saves. Mind Flayers will be saving at +1, with advantage for Magic Resistance.

It's not clear what you're trying to say here. Let's say gnome crawls around the corner, gets hit with a bunch of readied mind blasts. Assuming Int 16ish, gnomes are saving at +3 (with advantage) against DC 15, so if there's three Mind Flayers that gnome will fail about 1 save, get stunned (losing concentration on Darkness), and take about 10 HP of damage after resistance. How did going prone help the gnome, and what do you mean by "cones don't curve around the prone allies"?

I don't need to reread prone, but we are definitely thinking on different trains of thought here about why prone was iffy for me. What I meant was that going prone, and aiming just above allied mind flayers, also prone, would avoid any gnomes that also go prone. My players often say they cast their burning hand/dragon born breath cones "just so" that their allies wouldn't get hit, and I'd allow that to extend to the mind flayer Mind Blast cones as well. I was trying to squeeze out every possible advantage for the mind flayers, in that they don't need to hit other mind flayers too. Otherwise they are all literally standing shoulder to shoulder, which makes them more susceptible to enemy AoE for being so bunched up (which was more reason to make them go prone, in my eyes). Any more behind them to add to the "bunch of Mind Blasts" have no other choice but hit their allied flayer brethren.


If they've brought along a bunch of allies, then your Repelling Blast trick isn't even relevant in the first place. I was giving you the benefit of the doubt by assuming no allies.

Yeah we were on the same page here.


You don't think Mind Flayers can measure a 15' radius in their own tunnels? I do. Or the Elder Brain could just tell them, "Now!" since it knows exactly where you are at all times.

Problem is that talking, even telepathic, isn't a free action RAW: you can only do it on your turn. So even readying an action to work on a telepathic message wouldn't work super great. I'm not even sure talking counts as an action you can ready. But if that counts, then yeah the elder brain could also ready an action when they move in, it's true. But since talking is RAW only on your turn, out of your suggestions the option left the the flayers is waiting for measurements. Since the gnome had to cast Darkness on an item, they could just toss it out into the corner, or just hold out the tip of it. The flayers may know the center of the radius, but the gnome isn't in it. Wasted mind blasts again. Of course, the counter to that would be to change the general Ready trigger, but then it breaks down to getting extremely precise which bogs down the game. It's certainly bogging down this thread as I am adding to it.


I'm assuming a small number of Mind Flayers for your benefit, because if there are thousands then your plan is obviously totally infeasible and I assume you wouldn't even propose it. I imagine you're imagining about fifty Mind Flayers or less, total. Am I right? And you said before that you're expecting to fight them in groups of 2-3, so you've got to get through 15-20 fights.

Can you beat a group of 3 Mind Flayers with an Evard's Black Tentacles or Wall of Light? Sure, probably. Each time you cast the spell, about half of the Mind Flayers will fail their saves (+1 at advantage vs DC 17ish = 56% chance of failure), and then they'll hit you back, and you'll lose some HP and some spell slots and maybe get a PC's brain eaten. And then you burn more spell slots to keep Darkness up another 10 minutes, and then it's on to the next group of Mind Flayers, 15-20 more times, and that's if the Mind Flayers don't do anything halfway clever like cut off your retreat and envelope you from all sides (with thrall support as meat shields/distractions), or flood the tunnels and drown you.

Excellent points. Honestly if it's thousands it's not really a chance for the gnomes, I'll agree, they'll need the showstoppers of level 8/9 spells at that point. I was thinking of a small colony like you said. The more the flayers bunch up though, the better AoE gets, but you are right, warlocks have limited supplies of spell slots for AoE. They'd need to make them count.


You don't even need scrying. Just suppose that one of the warlocks is a chainlock. "How would the gnomes know the layout?" is not an objection I would raise, because the answer is obvious.

However, knowing the layout is different from knowing the disposition of enemy forces. The Mind Flayers certainly know where YOU are, and they have excellent command and communication facilities, thanks to the Elder Brain--what you need to worry about is, "If I go into THIS tunnel instead of THAT tunnel, what's going to come out of THAT tunnel and hit me from behind when I'm engaged from the front?"

Yadda yadda yadda. Knowing the layout is not a problem, we both know that. Relying on Repelling Blast and psychic damage resistance to stay alive is the problem--those things don't scale well enough to make it safe. Choose a different strategy.

More excellent points. My point is that the gnomes can scout and see the general layout and rough forces of the enemy, which may not give exact dispositions, but gives them a rough estimate to improvise around. But you've also made it "easier" on the warlocks since they don't need scrying either, but scrying negates some of the advantages the mind flayers can use. If the mind flayers can know the choke points, so could the gnomes via scouting. Bit of a tie there, but yes, additional allies could stop the intrepid gnomes, which I already agreed to.


I agree. I'm only critiquing a specific, suboptimal strategy (Repelling Blast warlocking). I'm not saying you can't do it, I'm just saying that is a bad way to do it.

And you are right. I was just spit balling. Every plan can absolutely fail. We could find a theoretical counter to every single option provided in this thread. Eldritch blasting with repel is just resource-less stuff the warlocks can do all day long while they think of better plans, and it can work in larger spaces where the illithids would get stuck due to range difficulties. It's a pretty low skill floor for what a warlock can do. It makes it less of a suicide mission than the OP first thought. And warlocks aren't even that good, as a fully rested Wizard would circumvent the issues of minimal spell slots, and be ever higher on their Int saves. I just like Warlocks.

[MaxWilson]

I getcha MaxWilson, I didn't explain every little detail of my spiel, so I'll give my reasoning for what I wrote. My main point is that both the mind flayers and the players can pull out weird tricks to stop the other, so it comes down to luck, and a party of level 10s can get fairly far even with few options at their disposal. I just started from Gnome GOOlock because they'd have some innate resistances to what the illithids could dish out. I know it isn't fool proof, because honestly, nothing is. Even Wish could just fail, and Divine Intervention has some limitations.*snip*

Ah, okay, then we are on the same page.

Honestly I think this scenario would be a blast. To me it says "adventure", not "campaign," and I wouldn't try to make it the focal point of a whole months-long campaign, but I'd totally spend 6-8 hours on it.

If I wanted a campaign setting I'd build in 7-8 other major powers on par with this particular mind flayer colony, and set them all at odds with each other, with the players caught in the middle. Mind Flayer colony, newly-crashed beholder Tyrant Ship taking slaves and territory from the other powers, a fire giant city-state with lots of human slaves, ancient dwarven nation turning to demons and blood sacrifice in desperation to survive, nation of mostly courageous and helpful (Lawful Good) bedoins ruled by selfish and tyrranical (Lawful Evil) Efreet nobles, an Ancient Red Dragon (Dragon Sorcerer 19) and its progeny exacting tribute from the humans in "their" territory but otherwise leaving them mostly free, a militaristic orc confederation doing mercenary work for the other powers, maybe a secret network of Yuan-ti and the few ancient hags they unknowingly worship, and a tyrannical necromanctic magocracy of halflings.

After all, I don't want the players to run out of stuff to do just because they besieged and then wiped out the Mind Flayers.

[Protolisk]

Honestly I think this scenario would be a blast. To me it says "adventure", not "campaign," and I wouldn't try to make it the focal point of a whole months-long campaign, but I'd totally spend 6-8 hours on it.

One of my last campaigns WAS this style. I actually expected the players to end up fighting the Mind Flayers' home base around level 12-15 or so, but they knew Flayers were creeping about from level 4. It was because of that campaign that I felt strongly about this topic, I had a lot of thought about it and how it could be countered. And the answer it came down to was that I couldn't outright plan for every contingency, with all the general nonsense that PCs tend to get into.

Pile up of giants, mind flayers (split into elder brain led illithids and Alhoon/Arcanist renegades), aboleths, yuan ti, necromancers and a "normal" human state with ties to a "nice" Beholder all vying for control over a "slumbering ancient power", which in reality was a Kraken that was manipulating each faction into destroying each other so it could rule instead, as it was the outright smartest thing in the whole place. Krakens be smart, yo.