Bonemass is a boss in Valheim.



"Wanderer, look to your feet, that tread upon our tomb. One thousand bones without their meat, will drag you to your doom."


Bonemass' summoning spot is found in the Swamp biome. His location can be found when visiting Sunken Crypts, where a Vegvisir will reveal the Forsaken altar on the map. The Runestone can also be found at stone tower ruins in the Swamp biome.


Ten (10) Withered bones must be used at the Forsaken altar to summon Bonemass.

Attacks & Abilities

Bonemass uses three different attacks:

  • When up close, Bonemass will raise his hand to swipe at the player (80 Blunt, 30 Poison and 2000 Terrain damage). Make sure to block or parry this attack, or run out of his range when it comes up.
  • At intervals, Bonemass will reach into his armpit to throw out a glob of goop. This is never directed at the player, and will spawn up to 4 random monsters (skeletons and/or blobs) where it lands. No more of a creature type will be spawned once 8 of that type are already present.
  • Bonemass will charge up with a thick green cloud before releasing a wave of poisonous ooze, poisoning everything in a wide range around him (100 Poison damage). This is signaled when he leans backwards. While in this poisonous cloud, you will constantly take damage even with poison resistance. Avoid being in it unless you have poison resistance and high health.
  • Environment aura that forces raining which means pulling him from the swamp can't be used to remove Wet.


  • The boss is significantly more difficult without Poison resistance mead. It is recommended to bring several per player. All of Bonemass attacks deal poison damage, and he can summon slimes, which can also poison. If you are low health avoid being poisoned so you can regenerate health.
  • His armpit glob summon is generally aimed away from players and has a very slow animation. If you are in melee range and see him prepping his armpit glob, he will be defenseless to attack. You can likely land several hits in a row. It is advised to focus on taking down his minions immediately after. If you are in a group, assign one person the task to kill minions as soon as they spawn, while the others punish Bonemass. If playing solo, you may be tempted to kite his minions instead of killing them. This might work initially, but eventually the sheer number of skeleton archers and slimes will become unavoidable.
  • When he prepares to vomit his cloud of poison (signaled by him leaning backwards), it is best to keep a large distance to avoid the poison entirely. Since Bonemass has no ranged attack option, he will have to follow you out of the poison to attack you, and then you can resume the fight out of the cloud.
  • While very strong and poison-inflicting, his hand swipe is very slow and predictable. You can generally dodge it simply by sprinting away, if timed correctly. This saves on stamina compared with blocking, parrying or rolling, but requires good timing and positioning. After you dodge its attack, you will have time for 2-3 melee attacks.

Preparation is key, and there is no such thing as too much. Using a hoe to level out the area you plan to use is a good idea; it will enable more mobility without jumping and sprinting through the swamp, in addition to removing leeches from the battlefield. If there are Draugr/Skeleton spawns and ruins nearby, be sure to clear them beforehand. It is also preferable to fight Bonemass as soon as a new day begins, to avoid the increased enemy spawn rate at night.

Bonemass, as well as his minions that he spawns, are weak to blunt damage. It is HIGHLY recommended to use iron maces or other forms of melee blunt damage.

A list of effective weapons, from best to worst:

Stagbreaker however is great for dealing with the skeletons & blobs when they are grouped up.

Pierce damage (including bows) is extremely ineffective, only consider using them to counteract Bonemass' health regeneration. However, Frost arrows are very effective, but require an Iron pickaxe to gather the required Obsidian.

Frostner is the ideal weapon for fighting Bonemass due it dealing both blunt and frost damage. It is possible to craft it prior to fighting Bonemass but finding the required silver is extremely difficult without the Wishbone.


Create safe spots up in trees or above crypts allows for getting short refuge while your mead cooldowns wear off, getting a bit of health regen, or just allowing you to pick off the adds without worrying about Bonemass. You can build a campfire inside the crypts, as well.

If you are using the direct engagement method, metal armor (preferably iron) and a Banded shield is highly recommended. The movement speed penalty is completely outweighed by damage mitigation. It is also recommended to have multiple Medium healing mead and high health food (Serpent stew and Sausages), as you will need to fight Bonemass close range and tank his attacks. Bonemass is the only boss who summons mobile adds which may have ranged attacks, so you need to be able to shrug off their attacks to survive without depleting your stamina.

A good strategy is to attack Bonemass with blunt damage in combos (three attacks in a row - the third giving nearly double the normal damage) quickly, during or after any of his attack animations and then running back to recover. If he releases the poisonous ooze, for example, you can take this as an opportunity to get a lot of extra combo hits in before retreating and using a health potion mead to recover afterwards - assuming you have the poison resistance mead active. It is also recommended that you take advantage of Eikthyr Power to reduce stamina drain from running and jumping so you can evade Bonemass or his spawns when you are low health.

Alternatively, frost arrows are highly effective against him. You will need an Iron Pickaxe and Frost resistance mead to farm obsidian in the Mountain, but it isn't difficult to create. Crafting a hundred or so frost arrows and shooting him from up high in the trees is a safe and easy (although rather unsatisfying) way of defeating Bonemass.


Building a structure, out of its reach, e.g. on top of a sunken crypt, is useful to take the aggro away from the other players.

One person should have the aggro of the boss and tank/dodge his swipes. Meanwhile, the other players can safely attack Bonemass from behind with blunt damage while it's slamming the aggroed player. When he uses the poison AoE attack, the group should move away from him. Bonemass can be lead away from the poison cloud he creates. You can survive walking through the poison, just don't stay in it. If you are low health avoid being poisoned so you can regenerate health.

It may be useful to have one player focused on killing the skeleton and blob spawns as soon as they land. While there is a cap on how many minions Bonemass can have spawned at once, to have additional enemies on the battlefield makes the battle considerably harder. Stagbreaker is a great weapon of choice for this minion-clearer.


There are a number of pluses and minuses to killing Bonemass. It would be wise to consider the player(s)' readiness before attempting to defeat Bonemass.


Item 0 Star 1 Star 2 Star
Wishbone.png Wishbone 1 per player
Bonemass trophy.png Bonemass trophy 1

Forsaken Power

Bonemass' power will activate a large amount of physical resistance for 5 minutes.


Defeating Bonemass also stops its story-based event where Draugar and Skeletons raid the players' base(s). However, this is switched out for enemy-based events (which can overlap with story-based events) with Blobs and Oozers, and skeletons and Rancid Remains. This may also unlock the story-based raid event of the 4th boss.

If the player has already killed a Surtling, defeating Bonemass will also unlock surtling enemy-based events.



Passive CrowDeerFishGullLeviathan
Aggressive BoarNeckGreylingGreydwarfGreydwarf bruteGreydwarf shamanTrollGhostSkeletonRancid remainsBlobOozerDraugrDraugr eliteLeechSurtlingWraithWolfDrakeStone GolemFenringDeathsquitoLoxFulingFuling BerserkerFuling shamanSerpent
Boss EikthyrThe ElderBonemassModerYagluth
NPC HuginHaldorHalsteinOdin
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