D&D 5E Balance Concern in Elder Brain/Ulitharid encounter(s)

[THEMNGMNT]

So what happens if they fail?

Do they die?

Or are they captured and implanted with mindflayer tadpoles?

I know which I would choose...

 

[Flamestrike]

My part of 6 is all 11th level, and are heavy on magic users: Eloquence Bard (control focus), Tempest Cleric (tank/healer/blaster swing), Wild Magic Sorcerer (blaster), Hexblade Warlock (striker), Scribe Wizard (controler) ... and their friendly Ancestral Guardian Barbarian (tank/striker).

Barring the Warlock, all your PCs are Long Rest dependent classes.

This strongly suggests to me that you dont police the adventuring day in your campaign, and your Players are routinely getting only 0-2 encounters between long rests.

Is that the case, and if not, how many encounters are they averaging between Long Rests?

So far, they've stomped through most "Deadly" encounters I've thrown at them, with the occasional KO but no deaths. I'm still not super confident in my ability to gauge the difficulty of encounters, despite years of 5e play, so I figured I'd ask for some input.

Encounter difficulty is only one part of the equation.

How many encounters per long rest is equally important.

Can you give me an example of a standard adventuring day for your group, and what it would look like?

 

[Stormonu]

You could do a 2-in-1; the character starts the fight against the Elder brain (and minions), upon its defeat a Ulitharid rises from the oozing hulk to do battle (the Ulitharid having been a construct/mind slave of the Elder brain to give it mobility).

I'm guessing with the party you have, an Elder Brain + 2 Mind Flayers + Warlock of the Great Old One, with the Ulitharid emerging when the Elder Brain hits 0 hit points should be an interesting fight (24,600 XP straight up, 36,900 XP adjusted). Should be hard-fought, but winnable (IMHO).

If you have the time, running a mock battle with something like DnDCombat simulator should help you gauge how the fight might go.

 

[Stalker0]

One other thing to consider. Since the bard was KOed, that means a psychic link should now be in place. Use that for all its worth, just feeding the bard false information can be a really cool way to shift the fight, things like:

• The bard knows there is a secret door in the elder brain's laid, and thinks it might be connected to disrupting the 3/4 cover field. Of course, this is complete garbage.
• The bard thinks that killing the hostages with electricity could actually deal super damage to the brain, providing an interesting morale choice. In reality, while yes it can remove the LRs, it won't actually hurt the brain at all.

Btw, love the idea of hostages = LR uses, very thematic.

Challenge wise, yeah its a tough fight, but again as a super epic fight for 6 11th level characters....I say let it ride. Yes the opening mind blast is going to be the big hit, but the fact they can still do a few things softens the blow.

Worse case, you could always knock them all out, and have them wake up chained and ready for experimentation. You have a fun breakout adventure, and then a few adventurers later (after the party has had a little time to forget) some of the players exhibit "odd" physical signs.....realizing in horror that while they escaped the illithid base, they have not escaped untouched.

 

[Stormonu]

• The Ulitharid - As the lieutenant, its job is to charge the heroes and protect the Brain. However, it values its own survival above the Brain's, and once below 1/3rd hp will planesh*t away.

Ha, ha - just noticed this typo and it's got to be one of the best I've seen in a long time, and a very apt accidental description.