Baldur’s Gate 3: Phase Spider Matriarch Boss Guide 

Don't let the spiderlings out.

As one of the earliest bosses in Baldur’s Gate 3, Phase Spider Matriarch belongs to the monster category and is one of the most difficult ones in the whole game. You will encounter this monster while visiting the Whispering Depths dungeon in Blighted Village. Phase Spider Matriarch is an optional boss, but we highly recommend taking it down for some sweet rewards.  

This guide will explain the location, strengths, and weaknesses of Phase Spider Matriarch. She is one of the most difficult early-game bosses and can wipe out your whole party in an instant. Make sure to read all the sections carefully and use our character creation guide to use your character’s strengths against Phase Spider Matriarch in BG3. 

Baldur’s Gate 3: Phase Spider Matriarch location

Phase Spider Matriarch is inside the Whispering Depths dungeon (X: 540, Y: -354). It can be accessed by going through the well in the village’s center. 

You can also reach this dungeon by entering the cellar of Apothecary’s House during the Search the Cellar quest. Phase Spider Matriarch is present at the end of the Whispering Depths, where she petrol her nest endlessly. 

Phase Spider Matriarch stats and weaknesses 

Phase Spider Matriarch has 15 Armor Class and 125 health. She can see in the dark and cover large distances to attack you and your party. With 19 strength, 16 dexterity, and a +2 proficiency bonus, She is a well-rounded boss fight in BG3.  

Phase Spider Matriarch is immune to poison and takes normal damage against all other attacks. She is not weak against any damage, so we don’t recommend focusing on a special skill or magic against her. 


Wyll’s Eldritch Blast can push her down from the bridge, so we recommend keeping him in your party. 

Preparing for the Phase Spider Matriarch boss fight 

Phase Spider Matriarch uses poison attacks against the players. We recommend using potions and gear items that increase your resistance against poison. 

This is a ranged fight, so we recommend keeping Gale, Wyll, and Shadowheart in your party. Fire Bolt and Fireball are must-have spells for this fight. We attempted it with an Evocation Wizard build with Magic Missile upcast, which made it a hell of a lot easier. 

Before starting the fight, sneak around her nest and destroy three sets of Phase Spider eggs with ranged attacks. Two sets are on the upper platforms, and one is on the floor nearing the patrolling phase spider. 

Ensure your party is at least level 5 or above before attempting this fight. 

How to defeat Phase Spider Matriarch in Baldur’s Gate 3 

Once you have taken care of all the eggs, initiate the battle. Phase Spider Matriarch will always start the fight by moving to her nest and hatching the eggs. If you manage to destroy all the nests, this will give you an upper hand in the boss fight. 

There are two more patrolling phase spiders in the area. They will immediately join the fight and hit you from a distance with poison attacks. To start the fight, hit the web bridge with Fire Bolt when the momma spider is walking on it. 

She is susceptible to fall damage and takes around 50 damage per fall. Three bridges in the area can be used for this purpose. Use Wyll to push Phase Spider Matriarch off the upper platforms to deal as much damage as possible. 

You can use Gale to deliver fire damage via Fireball to Phase Spiders. If you follow the strategy correctly and avoid melee combat, you can quickly overcome this battle. 


To earn the Pest Control achievement, you need to kill the Phase Spider Matriarch before she can hatch her eggs. Destroying the eggs will lock you out of the achievement. You can use a character with high Strength to shove her down into the chasm. 

During the Honor Mode, Phase Spider Matriarch uses a legendary action known as Gossamer Tomb. If you try to attack her children during a turn, she will use this action to enweb the attacker. 

How to Cheese Phase Spider Matriarch 

While it is difficult, you can cheese Phase Spider Matriarch. For this purpose, you will need at least 5 explosive barrels. Place these barrels near the nest on the floor. 

Use a character with high stealth to avoid detection by the roaming phase spider. Once the barrels are set, move the whole party to the upper platform and destroy the other two nests stealthily. 

Now, start the fight by destroying the web bridge. The Spider Matriarch’s phase is on. She will immediately move to her nest to hatch her eggs. Use any fire spells, like Fireball, to ignite the barrels. 

This attack, coupled with the fall damage, will be sufficient to kill Phase Spider Matriarch in one hit. However, you will still need to handle her children. 

Phase Spider Matriarch rewards 

Once the Phase Spider Matriarch dies, you can loot her body to obtain Poisoner’s Robe (10AC). This armor allows its wearer to deal an additional 1d4 poison damage with each spell (poison only).   

This is everything you need to defeat Phase Spider Matriarch in Baldur’s Gate 3

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Usman is an Associate Editor at Segmentnext who is obsessed with retro gaming. His love for video games begins all the way back in 91 with Final Fight on arcades and is still going strong ...