Illithid Arcanist

Illithid Arcanist is a type of hostile Aberration character in Baldur's Gate 3, many of which appear during several combat encounters at the High Hall and Atop the Netherbrain.

Attacks and Abilities

 Tentacle Whip ()

2d10 + 4 (6~24) Psychic

Lash out with your tentacles and possibly Stun your target.

INT Save

 Melee: 1.5 m / 5  ft

 Magic Missile ()

1d4 + 1 (2~5) Force

Create three darts of magical force, each dealing 1d4 + 1Force damage to its target.

The darts always hit their target, and can each be targeted individually.

 Range: 18 m / 60 ft

Shield

 Counterspell ()

Try to stop a spell being cast.

If it is higher level than the spell slot you used to Counterspell, you must make a check using your spellcasting ability^{[See Notes]} to prevent it. The check's difficulty is equal to 10 plus the level of the spell you are trying to counter.

 Mind Blast ()

4d8 (4~32) + Spellcasting modifier Psychic

Spew forth a conical wave of psychic energy and possibly  Stun targets within.

INT Save

AoE: 14 m / 47 ft (Cone)

Recharge: Long rest

 Mind Flayer Domination ()

Dominate a nearby humanoid. Allies are unaffected. Each time the dominated creature takes damage, it may repeat the Saving throw against your domination.

INT Save

 Range: 18 m / 60 ft

 Levitate (Illithid Power) ()

Float effortlessly to a destination.

 Range: 18 m / 60 ft

Recharge: Per Turn

Notes

• Illithid Arcanists have 2 variants: one with Fire Shield: Chill and Fire resistance, and another with Fire Shield: Warm and Cold resistance.
• Their version of Magic Missile deals more damage, fires more missiles, and has a significantly longer range. This makes them dangerous if not dealt with quickly.
• If pushed or thrown off the top of the Netherbrain during the final battle, Illithid Arcanists will simply teleport back to their former position.

Loot

• Random gemstone or alchemy ingredient