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.

Illithid Arcanist
Medium Aberration
Level 8 Mind Flayer
Stats
Armour Class	15
Hit points	55 (Balanced) 71 (Tactician)
Movement speed	9 m (30 ft)
Weight	60 kg (120 lb)
Initiative	+1
Ability scores
STR DEX CON INT WIS CHA 11 (+0) 12 (+1) 12 (+1) 19 (+4) 17 (+3) 17 (+3)
Proficiency bonus	+3
Saving throws	Str 0 Dex +1 Con +1 Int +7 Wis +6 Cha +6
Resistances
Resistant	Fire, Cold
Conditions
Fire Shield: Chill	Resistance to Fire, deal 2d8Cold to melee attackers.
Fire Shield: Warm	Resistance to Cold, deal 2d8Fire to melee attackers.
Features
Empowered Evocation	Add your INT Modifier to damage rolls with any evocation spells.
Magic Resistance	Advantage on saving throws against spells and other magical effects.
Opportunity Attack	Automatically attack an enemy moving out of your reach.

Attacks and Abilities

[[* Lash out with with your tentacles, dealing 2d10 + 4Psychic and possibly stunning your target.

 Melee: 1.5 m / 5  ft

Action]]

 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

[[* When you are about to be hit by an enemy, use your Reaction to increase your  Armour Class by 5. You also take no damage from  Magic Missile. These effects last until the start of your next turn.

Reaction]]

 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

[[* Float effortlessly to a destination.

 Range: 18 m / 60 ft

 Movement]]

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