Withered bone Valheim

Collect ten, prepare more than ten

Withered bones unlock the Bonemass attempt, but they do not make the attempt ready. Treat the tenth bone as the start of boss preparation: arena cleanup, food, meads, weapon durability, and a recovery portal.

Where to find Withered Bones in Valheim

Withered Bones drop from chests inside Sunken Crypts and from Draugr enemies in the Swamp. The fastest source is Sunken Crypt iron chests — each crypt typically holds 2–5 bones in the locked iron-barred rooms. You can also find them near certain Swamp structures.

• +Check every iron-barred chest inside the crypt, not just the muddy scrap piles.
• +Kill Draugr Elites for occasional drops if crypts are running dry.
• +Collect 12–15 so you have spares if the altar needs re-summoning after a wipe.

What is Bonemass weak to in Valheim?

Blunt damage. Iron Mace is the weapon that makes the fight significantly shorter. Poison Resistance Mead is equally critical — Bonemass's poison attack removes most of your health per tick without it. Prepare both before approaching the altar.