I need a human CR encounter calculator for extremelly high level encounter :D

[HoboKnight]

Hey guys,
at a certain point CR calculator is useless.

So I am preparing the end game BBEG (epic hag coven) and I'm using refluffed 3x Iggwilv the Witch Queen from The Wild Beyond the Witchligh (p. 205). 3x CR 20 each. And I could use an assessment of at what level would PCs be able to remotely defeat them?

Party:
Half-Orc Barbarian Berserker
Human Paladin of Vengeance
Elf Cleric of Life
Elf Rogue Assassin
Elf Conjuration Wizard

I know it's an impossible question, but... what is an educated guess regarding party level?

Thank you

[Opsimos]

The counterspells and Wishes make this very difficult to accomplish with a suboptimal party. My first impulse would be to spam antimagic field somehow, maybe with Simulacrum shenanigans.

[Beelzebub1111]

First step would be to calculate the true CR of the monster by plugging the stats into the DMG's section on creating monsters. Once you have that, you need to figure out what items your players have, having a +3 weapon can increase your character's hit chance by 9-13 levels. Bonuses to saves like on a cloak or ring of protection work the same way.

A safe bet for a challenge might be level 16, but depending on loadout they might be able to do it at 14 if someone has healing word. A lot of that is predicated on tactics and the GM's willingness to use devastating high-level spells on the party like Power Word Stun and Forcecage. If you have one cast sickening radiance and the other two wall of force to lock them into an enclosed space and nobody has a way to teleport out or disintegrate the wall you could TPK even parties of the highest levels without much effort.

[Silly Name]

Iggwilv is a pretty fearsome foe - she got good AC, good-ish HP, excellent saves, with Advantage against spells, and, most annoying of all, her Bewitching Bolt attack constantly forces saves against charm. If her Abyssal Rift goes well, she adds two more bodies to the party, and she has Counterspell but not really, so no Counterspelling her own counterspell.

She can also spam Fey Step as her bonus action to stay out of melee range, so the party needs some way to limit her movements.

So, let's look at the party as it is:

PROS:
- Three elves, who have advantage against being charmed. Very good.
- The Cleric and the Paladin can use their Concentration to make two party members immune to being charmed by Iggwilv thanks to Protection from Evil and Good.
- If the Barbarian is at least level 6, he can't be charmed while raging, and can even enter rage to end the charm on themselves.
- If the Paladin is at least level 6, Aura of Protection is online.
- A Cleric and a Wizard are always useful, and the Conjuration Wizard could summon some reliable extra monsters to help soak up damage (Summon Fiend (Devil) as an opener, most likely, followed by whatever powerful spells are at hand).

CONS:
- The opposition has a pool of nine Dispel Magics, three Wishes, three Mazes, and, if necessary, they can Polymorph into T-Rexes... Or, more dangerously, they can turn three of your party members into some harmless CR 0 Beasts.
- Fey Step spam + movement speed means that the Paladin and Barbarian need some way to keep chasing the witches (a paladin with a flying Greater Steed can pick up, but the steed will probably die at some point during the encounter).
- I hope the Rogue is a ranged combatant

IMHO, any group below level 15/16 is likely getting trounced with no chance of survival against three Iggwilvs. Even at the 16 to 18 range, good builds and tactics will be necessary to survive the encounter, and the PCs will also need a good array of powerful defensive and offensive magic items. The subclass selection tells me the party isn't really doing high-ends optimisation here, too.

You likely need access to 9th level spells to win, and some funky shenanigans to have enough DPR. Unless the Wizard is pulling some Magic Jar and Simulacrum cheese, in which case all bets are off the counter.