Baldur’s Gate 3 Boss Guides#
Overview#
Boss fights in Baldur’s Gate 3 revolve around preparation, terrain use, and control chains
| Boss | Act | Level | Difficulty |
|---|---|---|---|
| Phase Spider Matriarch | Act 1 | 4-5 | ★★☆ |
| Auntie Ethel | Act 1 | 4-5 | ★★★ |
| True Soul Nere | Act 1 | 5-6 | ★★☆ |
| Grym | Act 1 | 5-6 | ★★★ |
| Githyanki Inquisitor | Act 1 | 6-7 | ★★★☆ |
| Ketheric Thorm | Act 2 | 8-9 | ★★★★ |
| Isobel | Act 2 | 7-8 | ★★ |
| Raphael | Act 3 | 11-12 | ★★★★★ |
| Orin | Act 3 | 11-12 | ★★★☆ |
| Gortash | Act 3 | 11-12 | ★★★☆ |
| Netherbrain | Act 3 | 12 | ★★★★ |
| Red Dragon | Act 3 | 12 | ★★★★ |
Phase Spider Matriarch#
Location: Bottom of the well in the Blighted Village → Phase Spider nest Recommended level: 4-5
Boss traits:
- Summons spiderling swarms
- Can teleport — blink strikes from nowhere
- Weak to fire
Strategy:
- Send one character to smash the eggs — the spiderlings will swarm the eggs first
- Destroy the eggs: burn them with fire spells / oil + torch / bombs — prevents reinforcements
- The Matriarch can fall off the cliff: her teleport may drop her into the chasm — free fall damage
- Haste + Bless on your melee — burn her health bar down fast
Drops: Phase Spider venom gland (crafting material)
Auntie Ethel#
Location: Sunlit Wetlands / underground lair Recommended level: 4-5
Boss traits:
- Creates duplicates — three hags that keep swapping around
- Negotiation option — you can end the fight with a deal
- Weak to fire
Strategy:
- Spot the real hag: the true one carries a special marker — whichever body your Magic Missile / AoE spells fail to hit is the real one
- Interrupt the transformation: the hag turns into a giant monster — interrupt it with Counterspell / burst damage
- Don’t kill Mayrina: the hag threatens you with a hostage — put Mayrina to sleep with Sleep, then finish off the hag
Drops: Hag’s Hair (+1 to a stat of your choice), a magic staff
Grym#
Location: The Adamantine Forge Recommended level: 5-6
Special mechanic: Grym is immune to all damage — unless it gets hit by the forge hammer
Strategy:
- Lure it under the hammer: one character stands by the lever while the rest pull Grym directly under the hammer
- Pull the lever: when Grym is standing under the hammer, pull it — massive damage plus Overheated / vulnerability
- Burst during Overheat: after being smashed, Grym is overheated — every source of damage works now
- Repeat 2-3 times: lure → lever → burst → loop
- Watch the lava: the floor is ringed with lava — it hits very hard
Drops: Adamantine gear (choose armor, shield, or weapon)
Githyanki Inquisitor#
Location: Githyanki creche — Astral Plane Recommended level: 6-7
Boss traits:
- Surrounded by githyanki psionic warriors
- Wields a silence-inflicting weapon — damage + Silence
Strategy:
- Clear adds before the boss: wipe out most of the githyanki warriors in the outer halls before pulling the Inquisitor
- Counterspell: the githyanki cast Silence — counter it ahead of time
- Control first: Hold Monster / Hypnotic Pattern on the Inquisitor — then burst him down
- Silver Sword of the Astral Plane: if you can disarm him — this sword is legendary
Drops: Silver Sword of the Astral Plane (legendary)
Ketheric Thorm#
Location: Moonrise Towers — final battle Recommended level: 8-9
Three phases:
| Phase | HP range | Notes |
|---|---|---|
| Phase 1 | 100%-50% | Top of Moonrise Towers — Ketheric + followers |
| Phase 2 | 50%-0% (first bar) | Ketheric becomes the Apostle of Myrkul — a huge undead form |
| Phase 3 | Separate HP bar | The Nightsong (if alive) joins in — the ultimate form of the fight, on your side |
Core tactics:
- Phase 1: kill the adds fast — clear the followers first; Ketheric on his own isn’t that scary
- Phase 2: Haste — haste the whole party → focus the boss
- The Nightsong: if you spared the Nightsong in the Gauntlet of Shar — she comes to help you
- Counterspell: Ketheric raises undead — counter his resurrection spells
Raphael#
Location: The Hells — House of Hope Recommended level: 11-12
The hardest optional boss in the entire game
Boss fight features:
- Raphael has 666 HP
- Summons 4 pillars — each one buffs Raphael
- Phase 2: his whole body is wreathed in flame — melee attackers take damage on contact
Strategy:
- Kill the pillars first: all 4 pillars must go down first — otherwise Raphael is effectively invincible
- Raphael’s buffs: each pillar grants one of: fire immunity / physical damage reduction / spell reflection / healing
- Fire resistance for everyone: drink fire resistance potions before the fight
- Recruit the golem: the hell golem in the House of Hope can fight for you — persuade it to switch sides
- Hold Monster: it works on Raphael! — your melee get automatic crits against him
Drops: Raphael’s Foe (legendary maul), the Infernal Passport
Orin#
Location: Temple of Bhaal — the sewers Recommended level: 11-12
Boss traits:
- Unstoppable — once per round she becomes briefly invincible
- High crit potential — an assassin-type boss
Strategy:
- Spot the real body: after Orin shapeshifts, look for the marker next to her name — find what’s different
- Don’t let her win initiative: Orin’s initiative is extremely high — send in a character with the Alert feat first
- Knockdown control: Shove / Stun / Hold Monster — keep her from acting at all
Drops: Bhaalist armor
General Boss Fight Tips#
- Pre-fight buffs: Haste, Bless, Protection from Good and Evil, Heroes’ Feast — cast them all before combat starts
- Control first: don’t deal damage on round one of a boss fight — land control first (Hold / stun / sleep)
- High ground: take high ground whenever you can — ranged attacks gain +20% hit chance and damage
- Action Surge opener: Fighters / Paladins pop Action Surge on turn one for burst damage
- Haste = more control: Haste doesn’t have to go on your damage dealer — give it to your control caster so they can land one extra Hold
- Scroll army: have everyone carry Haste / Fireball / Counterspell scrolls
- Honour Mode heads-up: bosses gain Legendary Actions — check the wiki ahead of time to learn their patterns
Boss Resistances and Weaknesses#
| Boss | Resistances | Weaknesses | Immunities |
|---|---|---|---|
| Phase Spider Matriarch | Bludgeoning | Fire | Falling |
| Auntie Ethel | Poison | Fire, Force | Charm |
| Grym | All (except hammer) | Overheating | All standard damage |
| Ketheric | Necrotic | Radiant | Instant death |
| Raphael | Fire | Force | Fire |
| Orin | Piercing | Magic | Fear |
Pre-Fight Preparation Checklist#
| Item | Notes |
|---|---|
| Haste scrolls for everyone | The single most important buff — one scroll per character |
| Bless | Level 1 — +1d4 attack and saves for the whole party |
| Heroes’ Feast | Level 6 — +12 HP and poison immunity for the whole party |
| Fire resistance potions | Against fire bosses like Raphael |
| Invisibility / Misty Step | Repositioning |
| Counterspell | At least two party members carry it |
| Water bottles | Wet condition → doubles ice / lightning damage |
Spell Slot Management for Boss Fights#
| Spell slot | Recommended use | Notes |
|---|---|---|
| Level 1 | Bless, Shield | Pre-fight buffs + survival — never waste these on damage |
| Level 2 | Hold Person, Misty Step | Control + mobility — the core of boss fights |
| Level 3 | Haste, Fireball, Counterspell | Party-wide buffs + add clearing + spell countering — the most important slot level |
| Level 4 | Death Ward, Dimension Door | Survival + mobility — mandatory in Honour Mode |
| Level 5 | Hold Monster, Conjure Elemental | All-purpose boss control + an extra meat shield |
| Level 6 | Chain Lightning, Heal | Final burst damage + the strongest single-target heal |
Honour Mode Boss Extras#
Act 1 Honour Mode Boss Strategies#
| Boss | New Honour Mode threat | Counter | Level |
|---|---|---|---|
| Auntie Ethel | Legendary Action: summons a duplicate every round — duplicates can cast spells — clear them before hitting the real body | AoE like Fireball / Lightning Bolt clears duplicates — single-target focus on the real body | 5+ |
| Grym | Legendary Action: gains an overheated rage after being hammered — doubled attack power and ignores resistances | Control your damage rhythm — retreat right after each hammer strike until Overheated fades, then burst | 6+ |
| Inquisitor | Legendary Action: summons githyanki psionic warriors — the whole party is Feared for 2 turns | Drink fear immunity potions before the fight — or spread out so the whole party can’t be locked down at once | 7+ |
Act 2 Honour Mode Boss Strategies#
| Boss | New Honour Mode threat | Counter | Level |
|---|---|---|---|
| Ketheric Thorm | Legendary Action: heals 30+ HP every round — summons 3 undead — necrotic aura deals constant damage | Kill him within the first 3 rounds — otherwise his healing outpaces your damage — bring radiant damage on everyone | 9+ |
| Moonrise Towers guards | Legendary Action: reinforcement signal — summons 2 extra guards every 2 rounds | Kill the signal caller first — cut off reinforcements — or clear the arena fast | 8+ |
Act 3 Honour Mode Boss Strategies#
| Boss | New Honour Mode threat | Counter | Level |
|---|---|---|---|
| Raphael | Legendary Action: summons a pair of succubi every round — they charm your party members — charmed allies attack you | ||
| Orin | Legendary Action: after transforming she becomes immune to the damage type she just took — it switches every round — fire / ice / lightning / radiant / force | Give every party member a different damage type — make sure every type is covered | 12 |
| Gortash | Legendary Action: Steel Watcher support — Steel Watchers throw bombs every round — AoE fire damage | Burst the Steel Watchers first — cut down the damage sources — then focus Gortash last | 12 |
| Netherbrain | Legendary Action: empowers Mind Flayers every 3 rounds — psychic damage to the whole party — Mind Flayers heal | Push forward fast — don’t linger inside the brain — focus the core — go all out in the final phase | 12 |
General Honour Mode Boss Tips#
| Tip | Notes | Importance |
|---|---|---|
| Research before the fight | Learn each boss’s Legendary Actions — build a targeted plan — never start a fight blind | ★★★★★ |
| Invisibility escape | If things go south — have the whole party drink invisibility potions and run — revive fallen allies out of combat | ★★★★★ |
| Insurance buddy | At least one character carries a Scroll of Revivify + invisibility potion — even a full party wipe isn’t the end | ★★★★★ |
| Control chains | Don’t deal damage on round one of a boss fight — control first — fewer boss turns | ★★★★☆ |
| Focus fire | Don’t spread your damage — pile it onto one target — shrink enemy numbers fast | ★★★★☆ |
| Potion use | Use potions freely mid-fight — they cost a bonus action — not your main action | ★★★☆☆ |