Bonemass Boss Guide: How to Summon and Beat the Third Boss

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How to Summon Bonemass.png
This is a boss battle guide on how to summon and beat Bonemass, the third boss of Valheim. Read on to find out what you need to summon Bonemass, its attack patterns, and how to beat it!

Bonemass General Info

Valheim Bonemass.png
Behavior Hostile
Health 5000
Damage 70~80 Melee
Weakness ・Blunt
Resistance ・Slash
Tameable? No
Enemy Spawn Code Bonemass

Bonemass Location

Activate Bonemass' Vegvisir

Bonemass' Vegvisirs are typically found near abandoned structures and houses within Swamp biomes. Sunken Crypts may also contain one of these vegvisirs.

Look for the Skull Altar

Valheim (Bonemass) - Find the Skull Altar.png
Activating Bonemass' vegvisir will reveal one of its Skull Altars on your map. These are found within Swamp biomes as well.

How To Summon Bonemass

Sacrifice Ten Withered Bones

Valheim (Bonemass) - Sacrifice Ten Withered Bone.png

Hint "Cook their remains."

Gather ten Withered Bones by exploring Sunken Crypts within Swamp biomes.

Activate the skull altar by placing the Withered Bones in your toolbar and pressing the number associated with its slot.

How To Prepare for Bonemass' Fight

Use Blunt Weapons

Valheim (Bonemass) - Blunt Weapons strategy.png
Bonemass is highly resistance to pierce and slash damage. Blunt weapons such as Maces, Clubs, and Hammers are the most effective against it!

Go Iron or Go Home

Valheim (Bonemass) - Go Iron or Go Home strategy.png
Bonemass' damage can be too much for bronze armor or lower — especially during solo play. It is recommended that you and your allies craft iron scale mails, greaves, and helmets before taking Bonemass on!

Take your time and explore Sunken Crypts in the swamp biomes. These dungeons are excellent sources of Scrap Iron, which is then refined into Iron.

Prepare Potions

Valheim (Bonemass) - Prepare Potions strategy.png
Bonemass' can easily inflict poison damage with its attacks. This can become problematic for you and your allies if left unchecked.

Potions such as the Poison Resist Mead and Medium Healing Mead are excellent items to manage Bonemass' insane damage over time!

Build a Base or Portal

Valheim (Bonemass) - Build a Base or Portal strategy.png
It is always recommended to build a small base with beds or a portal to and from your actual base near a boss' summoning altar.

This allows you and your allies to quickly jump back into the fray if things go south!

Ideal Food Combo

Sausages can easily take your maximum HP to about 150 when paired with Cooked Meat and Grilled Neck Tails.

Item Name How to Get
Can be cooked from the Cooking Station with the right ingredients.
Can be cooked from the Cooking Station with the right ingredients.
Can be cooked from the Cauldron with the right ingredients.

Bonemass' Attack Patterns


Valheim (Bonemass) - Swipe Attack.png
Bonemass uses one of its massive arms to do frontal swipe, inflicting poison damage over time to anyone it connects with.

It is important to note that the poison damage will push through regardless if you block or parry the attack.

Armpit Bomb

Valheim (Bonemass) - Armpit Bomb Attack.png
Bonemass grabs a ball of goop from one of its armpits and tosses it in a player's general direction, spawning skeletons and blobs on impact.

Poison Cloud

Valheim (Bonemass) - Poison Cloud Attack.png
Bonemass ejects its material within, creating a poison cloud in a large radius. Anyone caught in the cloud suffers high poison damage over time.

Bonemass Boss Strategy

Watch its Body Language

Valheim (Bonemass) - Watch its Body Language 2.gif
All of Bonemass' attacks are heavily telegraphed by its arms and head. Refer to the table below for each attack and their respective telegraphs:

Attack Telegraph
Swipe Bonemass will stretch one of its arms out before swiping its front.
Armpit Bomb Bonemass reaches into one of its armpits for a ball of goop.
Poison Cloud Bonemass will raise both arms sideways or stretch its head upward before ejecting a massive poison cloud.

Keep Tabs on its Minions

Valheim (Bonemass) - Keep Tabs on its Minions 2.gif
Bonemass' Armpit Bomb attack summons skeletons and blobs in its impact zone. Make sure you eliminate Bonemass' minions to avoid getting overwhelmed! The Iron Sledge and Stagbreaker are excellent weapons to deal with closely grouped minions.

Use Eikthyr's Forsaken Power

Eikthyr's forsaken power reduces the stamina usage when running and jumping by 60% when activated, and lasts for 5 minutes.

This is an extremely useful power to have against Bonemass since you will be moving around a lot throughout the fight.
Eikthyr's Forsaken Power

Bonemass Rewards

Bonemass Drops

Item Qty. Drop Rate
Wishbone Icon Wishbone Level 1: 1 Level 1: 100%
Bonemass Trophy Icon Bonemass Trophy Level 1: 1 Level 1: 100%

Bonemass Forsaken Power

After beating Bonemass, Bonemass Trophy item should drop. Taking it to the Forsaken Altar and hanging the trophy will grant you access to Bonemass' Forsaken Power. Equipping it and activating it will grant you increased damage resistance to physical damage. This can help you tank damage and help you survive longer against physical hits.

List of Forsaken Powers

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