Baldur's Gate 3 Act 3 Complete Walkthrough: All Quests, Endings, and Best Strategies Guide

TL;DR

• This Baldur's Gate 3 Act 3 walkthrough covers every main/side quest, key decision consequences, boss strats, and all three main endings
• We break down step-by-step progression to avoid broken quests and hit all the best loot before the final encounter
• Hardcore min-max tips for the final Netherbrain DPS check, including exact HP thresholds and damage breakpoints
• Full tier ranking of Act 3 legendary weapons, with must-have vs skip verdicts

Act 3 Area Overview

Act 3 of Baldur's Gate 3 drops you right into the heart of the Lower City, a 2.8km² open area packed with 47+ quests, 12 unique boss encounters, and three distinct main endings locked behind your choices throughout the entire game. This chapter guide is built for players who've already cleared Act 2, know the base mechanics, and want to avoid the common quest-breaking bugs that still plague BG3 in 2025 while grabbing every piece of endgame loot.

Act 3 is split into three primary zones:

• Lower City (levels 9-11): Main quest hub, 80% of side content
• Upper City (levels 11-12): Endgame side quests and the Gortash confrontation
• Bhaal Temple / Netherbrain Colony (level 12): Final boss gauntlet and ending sequence

You'll hit level 12 (the current max level) around 2/3 of the way through the Lower City, so we'll structure this progression walkthrough to get you there early while grabbing all the best feats and gear before the final fight.

Step-by-Step Main Quest Progression

Follow this exact sequence to avoid broken quests (a common issue when you storm the Upper City too early). This step-by-step walkthrough guarantees you hit every main story beat and unlock all side content:

1. Lower City Opening: Get Your Bearings (After Entering Through the Gate)

1. Deal with the Flaming Fist guard checkpoint: Pass the DC 18 Persuasion check to avoid fighting, or kill them for 120 XP and a +1 Longsword. Don't sneak past - you'll lock out the "Find the Missing Shipment" side quest early.
2. Head straight to the Elfsong Tavern to meet with Raphael. Never accept his deal to remove the tadpole - it locks out the good ending and gives you a permanent -2 to all charisma checks for the rest of the game.
3. Speak with Mammon at the tavern bar after the Raphael cutscene to pick up the "Murder in Baldur's Gate" main quest.
4. Rescue Volo from the Flaming Fist camp near the tavern entrance: Pass the DC 16 Deception check to get him for free, he'll give you the Volo's Ersatz Eye that gives permanent true sight - no exceptions, this is a must-grab.

2. Clear All Lower City Side Content Before Moving to Upper City

90% of broken Act 3 quests happen because players rush to the Upper City before wrapping up Lower City content. Follow this order:

1. Clear the "Githyanki Creche" follow-up quest at the Rambling Inn: Kill Vlaakith's envoy, get the Silver Sword of the Astral Plane (1d8+1 slashing, +2 to attack vs aberrations, 10% chance to stun on hit - S-tier for melee fighters)
2. Complete "Find the Missing Shipment" at the Sharess' Caress: Open the hidden chest in the basement to get the Knave's Robe (+2 DC to all spell saves, B-tier for Arcane Tricksters)
3. Clear the Lower City Sewers for the "Escape the Underdark" follow-up: Find the Bhaal cult entrance early, don't go in yet - we'll come back after you hit level 12.
4. Complete the "Murder in Baldur's Gate" quest line: Expose the Bhaal cult, kill the Open Hand Temple killers, get the Amulet of Bhaal (+2 Strength, breaks poise on every first hit - S-tier for all melee builds)

3. Unlock and Clear Upper City

1. Get the Upper City pass from Gortash's invitation after you complete the Murder quest - it's automatically sent to your camp. If you killed Gortash early, you can pickpocket a pass from a Flaming Fist captain near the Lower City gate (DC 20 Sleight of Hand).
2. Clear the Counting House quest for the Stone Lord: Get the 10,000 gold payout (keep it, don't give it back - you need gold for Act 3 consumables) and unlock the Vault of Wyrms.
3. Confront Gortash in the Upper City palace: This is a mandatory boss fight at 300 HP, 18 AC, and he deals 2d6+4 bludgeoning plus 2d8 thunder damage per hammer hit. He has 2 bodyguards with 80 HP each - focus the bodyguards first to avoid being stun-locked.
4. After killing Gortash, grab the Horn of Valhalla from his body - it summons 2 berserkers with 65 HP each for 10 turns, one use per long rest. This is a game-changer for the final Netherbrain fight.

4. Bhaal Temple and Orin the Red Boss Fight

1. Head to the Sewers Bhaal entrance after killing Gortash - Orin will kidnap one of your companions (usually Gale if you have him in your camp). Bring Lae'zel or Astarion for extra dialogue damage if you romanced them.
2. Pass the DC 20 Religion check to bypass the first three cultist fights, saving you 20 minutes of pointless combat.
3. Orin boss fight stats: 420 HP, 20 AC, 4 attacks per turn with Deadly Dance that deals 1d10+5 piercing per hit, plus a 25% chance to poison for 5 damage per turn for 3 turns. Her low Fortitude save (13) means hold person will land 75% of the time on a level 12 caster - melt her before she can split into clones.
4. After killing Orin, grab the Corpsemaker dagger (1d4+7 piercing, 1d8 necrotic, instant kill on targets under 20 HP - S-tier for rogues) and the Netherstone.

5. Final Gauntlet to the Netherbrain

Once you have all three Netherstones (from Gortash, Orin, and Ketheric Thorm from Act 2), head to the docks and take the flying ship to the Netherbrain Colony. There's no turning back after this point, so make sure you've wrapped up all side content first.

Key Decision Points & Consequences

Every major choice in Act 3 shapes your ending and permanent companion approval. Here's the breakdown of what matters:

All Endings Breakdown

There are three main endings, with minor variations based on companion choices:

1. Good Ending (Destroy the Netherbrain): Unlocked by refusing all deals, keeping at least one Netherstone, and destroying the brain. This ends with tadpoles removed from the world, your character survives (unless you sacrifice yourself), and Baldur's Gate is saved. This is the only ending where all companions can survive.
2. Absolute Ending (Control the Netherbrain): Unlocked by accepting Raphael's deal or allying with Gortash. You take control of the Absolute, rule Baldur's Gate as a tyrant, and all good-aligned companions are dead or exiled.
3. Bhaal Ending (Become the Slayer): Unlocked by becoming Bhaal's Chosen. You destroy the Netherbrain, become the new god of murder, and raze Baldur's Gate to the ground. Only evil companions stay with you.

Boss Encounters Summary (Hardcore Strats)

Here are the stat blocks and one-shot strats for every major Act 3 boss:

Notable Loot: Act 3 Legendary Tier List

All legendary and unique items in Act 3, ranked by usefulness for endgame:

Side Content Available (What's Worth Your Time)

Act 3 has a ton of side content, but not all of it gives good loot or XP. Here's what to prioritize:

• Must-