How to Summon and Defeat Bonemass
- Biome: Swamp
- How to summon it: Sacrifice 10 Withered Bones at its altar
- Rewards: Wishbone, used to find hidden treasure chests and silver ore, Bonemass trophy, Bonemass power
Bonemass is Valheim’s third boss, and he can be found in the Swamp. To discover his location, interact with a runestone found in swamp crypts, which you can access with the swamp key you got from The Elder.
You can check other Valheim guides:
- Valheim How to Summon and Defeat The Elder
- Valheim How to Summon and Defeat Eikthyr
- Valheim How to Summon and Defeat Moder
- Valheim How to Summon and Defeat Yagluth
- Valheim Item IDs & Spawning Guide
- Valheim Admin Commands for Your Server
Swamp crypts will also contain withered bones. You’ll need to find 10 withered bones to summon Bonemass at his altar.
Bonemass has three attacks. He has a melee strike he’ll use up close. He also has a toxic attack which fills the air and does severe poison damage if you’re caught in it. His third attack is summoning, and he’ll summon skeletons, blobs, and oozers to join the fight.
Strategy for Bonemass
Even though this is the third boss of five, it may actually be the toughest fight in the game. Bonemass is highly resistant to all forms of damage except blunt attacks. You’ll want to use iron armor and blunt weapons like maces and hammers (like Stagbreaker) against him, and staying close enough to connect. Ranged attacks with bows and arrows are almost entirely ineffective. Even a fully upgraded wooden club will do more damage than arrows. Bonemass also heals during a fight, so you need to keep up the assault constantly.
With the toxic attack doing so much damage, you’ll want to have plenty of poison resistance mead with you, so you should unlock the cauldron and fermenter long before you think about tackling this boss.
After defeating Bonemass, placing his trophy on the sacrificial stone will grant you a power that increases your resistance to physical damage.