Phase Spider Matriarch

The Phase Spider Matriarch is a type of Monstrosity creature in Baldur's Gate 3. It is a boss encounter in the Whispering Depths and possesses several powerful abilities.

Phase Spider Matriarch
Stats
Level 4
STR 16 (+3) DEX 19 (+4) CON 14 (+2) INT 6 (-2) WIS 12 (+1) CHA 6 (-2)
Race	Phase Spider
Type	Monstrosity
HP	125; 162Tactician
AC	15
Movement Speed	9m / 30ft
Size	Large
Weight	250kg / 500lbs
Proficiency Bonus	+2
Initiative	+3
Passive features
Opportunity Attack  Web Walker  Darkvision
Resistances
Character information
Location	Whispering Depths
Allies	Phase Spider, Phase Spiderling
In-game

Attacks and Abilities

 Venomous Bite

• Deals 2d6Poison damage and 1d8Piercing damage, and possibly injects a venom that deals 2d6Poison for 2 turns.
• Possibly  poison the target on a failed Constitution saving throw.

 Venomous Discharge

• Spit out a venomous substance that deals 4d6+4Poison damage and possibly  Poison those it hits.

 Poisoned 2 turns Constitution saving throw Attack roll  Range: 12 m / 36 ft

 Ethereal Jaunt

• Teleports the user to another location within 22m.

 Matriarch's Call

• Hatches a nearby clutch of eggs and spawns several Phase Spiderlings.

 Spider Queen's Wrath

• Below 50% Hit Points, the Matriarch gains Spider Queen's Wrath.
•  Spider Queen's Wrath

• Creature is enraged! Strength increased by 2,  Armour Class reduced by 1.

Tactician Difficulty:

• Creature is enraged! Gains an additional attack per turn. Strength is increased by 2 and has Resistance to physical damage.

Tactics

• When combat begins, the Matriarch will attempt to hatch her nearby Phase Spiderling eggs. These eggs can be destroyed before the battle begins if the party can stay hidden. Failing that, area damage spells work well on their low Hit Points.
• The Phase Spider Matriarch will use its phase abilities to teleport around the arena.
• At 50% or less Hit Points, the Matriarch will cast Spider Queen's Wrath on itself, entering into an enraged state.
• Knocking the Phase Spider Matriarch into one the side holes labelled 'Chasm' will grant the party 250xp. However, knocking her into the center hole (not labelled 'Chasm') will not grant experience, but its corpse can be found in the Underdark (X:140 Y:151) to loot and possibly animate.
• Using Alchemist's Fire (or other fire spells) when the Matriarch is on a web bridge, will destroy the web bridge and causes 45 fall damage and can help defeat her.
• Use Elixir of Poison Resistance on all your party members before entering combat
• Lump the Enlightened and his ogres can prove valuable allies in the battle. They can be recruited just up above in the Blighted Village through a Charisma check or paying them 500g. This can result in a win-win situation where Lump is killed in the battle or is significantly weakened allowing the opportunity to easily obtain the Warped Headband of Intellect.
• She has +1 bonuses to Strength and Dexterity on Tactician difficulty, with resultant bonuses to Initiative, Armour Class, Attack rolls, and Saving throws, making an already fairly fierce early game enemy even deadlier.
• It's a good idea to spread your party members out. Her venomous discharge ability has a large AoE radius.

Loot

• Poisoner's Robe