Baldur's Gate 3: Complete Walkthrough & Boss Guide
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🗺️ Main Story Walkthrough
Tick off each step as you go — your progress saves locally, no account needed.
You wake on a crashed Mind Flayer ship and must escape with a tadpole embedded in your skull before it transforms you. This segment teaches the D&D 5e-based turn-based combat system, including attack rolls, saving throws, and the importance of high ground for ranged advantage. Recruit Shadowheart immediately after landing; she is the most immediately useful healer in the early game. Before leaving the beach crash site, find the locked Palanquin container near the stern wreckage — it holds a Studded Leather Armor that outclasses most Act 1 vendor gear.
The central crisis of Act 1 is deciding the fate of the Emerald Grove, a Druid sanctuary sheltering Tiefling refugees under threat from a goblin army led by three Absolute cult leaders. Recruit Wyll and Lae'zel as companions in the early exploration around the grove. Your primary objectives are locating the goblin camp at Shattered Sanctum and eliminating all three cult leaders: Priestess Gut, Minthara, and Dror Razglin. Taking the time to enter the Underdark via the Whispering Depth hatch in the blighted village opens access to the Adamantine Forge and some of the best crafting gear in Act 1.
The Underdark is an optional but richly rewarding detour beneath Act 1, containing the Arcane Tower, the Myconid Colony settlement, and the Adamantine Forge dungeon. Defeating Grym at the Adamantine Forge lets you craft Adamantine armor and weapons — the Adamantine Scale Mail is arguably the best medium armor available until late Act 2. Collect the Sussur Bark from the Arcane Tower basement to craft a Sussur Weapon back in camp, which silences targets on hit and is exceptional against spellcaster enemies. Completing the Underdark connects to the Mountain Pass route into Act 2.
Act 2 takes place in a region permanently blighted by the Shadow Curse, which deals damage to anyone who leaves areas of magical torchlight. Escort the Tieflings or travel via the Mountain Pass to arrive at the Last Light Inn, the only safe hub. Your primary mission is infiltrating Moonrise Towers, the Absolute cult headquarters, and confronting Ketheric Thorm. Before assaulting the towers, complete the Gauntlet of Shar dungeon beneath the Shadowfell to unlock Shadowheart's full backstory and gain the powerful Spear of Night weapon. Resolving the Nightsong quest before the Ketheric fight provides a major combat ally for the Phase 2 encounter.
Ketheric Thorm is the Act 2 boss, fought in two distinct phases separated by a dramatic descent into a Mind Flayer Colony beneath Moonrise Towers. Use the Restoration Pod to the right of the elevator to fully restore all HP and spell slots before Phase 2 — it can be used repeatedly. Free the Nightsong in Phase 2 using a character with high movement or Misty Step; her assistance is decisive against the Apostle of Myrkul form. AoE spells like Moonbeam deal bonus damage against the Apostle because his movement through the beam counts as multiple triggers per turn.
Act 3 opens with arrival in Baldur's Gate, a sprawling city filled with dozens of quests, faction politics, and companion personal storylines. The Steel Watchers enforcing order are eventually revealed as a vulnerability in the Gondians' plot, and disabling the Steel Watch Foundry makes the final act far less punishing. Complete all companion quests now — Gale's, Wyll's, Shadowheart's, and Astarion's — before proceeding past the point of no return at Wyrm's Rock Fortress. Pick up the Blood of Lathander mace from the Rosymorn Monastery if you missed it, as it is one of the strongest endgame weapons available.
Infiltrating Raphael's House of Hope is required if you want to recover the Orphic Hammer needed to free Orpheus, a major late-game choice. The House of Hope is also home to legendary loot including the Helldusk Armor set and Gauntlets of Hill Giant Strength. Before triggering combat with Raphael, use the restorative pool in his bedroom to top off all spell slots, then apply Bless, Freedom of Movement, and Fire Resistance to the party. Free Hope first — her Revoke Guest Status ability is essential to winning the fight. Destroy the four Soul Pillars before engaging Raphael directly; each pillar takes only two bludgeoning hits to destroy.
The final sequence culminates in a large-scale battle in Baldur's Gate followed by a two-phase fight against the Netherbrain. Your party must get your illithid character to the Crown of Karsus on the opposite end of the brain under significant time pressure — a Nautiloid arrives after turn five on Tactician and begins bombing the battlefield. Approach along the side platforms rather than walking directly on the brain's surface to avoid triggering sixteen hidden tentacles. In Phase 2, deal 200 damage to the Unbreakable Will within five rounds; Save all your strongest damage abilities and spell slots for this phase, as failure is a game-over.
⚔️ Boss Guides
Auntie Ethel (The Hag)
Attack Patterns
Auntie Ethel is fought in her lair beneath the Riverside Teahouse after a maze of traps, poisonous vines, and Whispering Mask servants. She begins by hurling a firebomb at Mayrina's cage, setting it on fire each turn. She then splits into four identical copies — three illusions and the real Hag. If she acts freely she uses Hold Person and a powerful melee claw that inflicts the Frenzy condition. She attempts to remain in melee range and will repositiion aggressively.
Strategy
Douse Mayrina's cage with a water cantrip before combat starts to permanently neutralize the fire threat. Identify the real Ethel by her red clothes versus the blue-clad clones. Cast Silence on her position to prevent Hold Person, then keep her Prone using Grease, Shove, or the Topple weapon action — a Prone creature cannot take reactions and has Disadvantage on attack rolls. Magic Missile auto-hits and breaks Concentration if she manages to cast Hold Person. Kill any Redcaps in the lair before initiating the boss fight to prevent them from flanking during the clone phase.
Grym (Adamantine Forge)
Attack Patterns
Grym is a massive Adamantine construct guarding the Adamantine Forge in the Underdark. Without the Superheated condition applied by lava exposure, Grym is completely immune to all damage types. He moves slowly but his melee slam deals enormous damage and can knock characters Prone. Every three rounds the lava flow shuts off automatically. He has no ranged attacks whatsoever, making ranged characters safe as long as they stay on the raised platforms.
Strategy
Station one character permanently at the lava valve and another near the central crucible lever. Lure Grym into the lava pool by running through it — he will follow, gaining the Superheated condition. Immediately pull the forge lever once Grym stands on the crucible at the center; the forge hammer deals roughly half his HP in a single blow. Repeat the lava cycle and hammer strike once more to finish the fight. If you prefer the ranged cheese strategy, simply shoot him from the raised scaffolding platforms he cannot reach — it takes longer but he can never retaliate.
Ketheric Thorm
Attack Patterns
Phase 1 takes place atop Moonrise Towers where Ketheric is flanked by a skeleton dog and Necrolites he summons continuously. He uses melee sword attacks and targeted necrotic strikes but cannot be killed here — at 40% HP a cutscene triggers and the fight moves to the Mind Flayer Colony. Phase 2 pits you against Ketheric in his Apostle of Myrkul form alongside spawning Mind Flayers. The Apostle moves unpredictably and his Myrkul's Presence aura prevents healing for any character in melee range.
Strategy
In Phase 1, use Turn Undead (Cleric Channel Divinity) to trivialize the Necrolite spam and Hold Person to lock Ketheric in place for concentrated damage. Use the Restoration Pod by the elevator before descending — it restores full HP and spell slots and can be used multiple times. In Phase 2, free the Nightsong immediately using Misty Step or a high-movement character — she is a decisive damage dealer. Keep a buffer around the Apostle form and use AoE spells like Moonbeam and Cloud of Daggers that trigger multiple times per turn as he shifts position.
Raphael
Attack Patterns
Raphael is fought in his private arena in the House of Hope. Four Soul Pillars around the arena empower him with massive buffs as long as they stand. At 60% HP he transforms into his true devil form, gaining melee swipe attacks and faster movement. He is resistant to Fire, Cold, Lightning, and Poison, and reflects Radiant spells back as Fire damage through his Punish Divinity reaction. He summons devil minions throughout the fight.
Strategy
Before combat, buff the entire party using the restorative pool in Raphael's bedroom: apply Bless, Fire Resistance, and Freedom of Movement. Free Hope in the prison wing — her Revoke Guest Status ability is essential and makes the fight significantly easier. Destroy all four Soul Pillars with two bludgeoning weapon hits each before engaging Raphael. Cast Hunger of Hadar on his position to impose Blindness and ongoing damage, then maintain pressure with Force damage spells and melee attacks. Avoid all Radiant damage builds entirely. Karlach's Tiefling fire resistance makes her naturally durable against Raphael's entourage.
The Netherbrain
Attack Patterns
Phase 1 takes place across the surface of the Netherbrain with hostile Mind Flayers, a red dragon, and Dream Guardians. Hidden tentacles emerge on any tile players walk on directly. A Nautiloid gunship arrives after turn five on Tactician, bombing the arena. Phase 2 is a race: the Unbreakable Will of the Netherbrain must receive 200 damage in five rounds. It uses Psionic Retribution (a reaction that hits nearby allies with Psychic damage) and deploys Orbs of Negation that destroy the platforms beneath them.
Strategy
In Phase 1, prioritize the dragon with Hold Monster — a stunned dragon wastes multiple turns and removes the most dangerous burst-damage threat. Approach the brain interior via the raised side platforms to avoid triggering the tentacle field. In Phase 2, spread party members across multiple platforms to avoid Orb of Negation chain-destruction and commit every available spell slot and ability charge to the Unbreakable Will in round one. Save your illithid character's full action each round specifically for the Crown of Karsus channeling. One party member should focus purely on protecting the channeler from Incapacitate effects.