How to summon Bonemass.
In order to fight Bonemass, of course, you have to summon him first like any other boss. The flétris are needed to report big silt, 10 of them to be precise, and they can be found around Swam from Sunken Crypts.
After taking the first step and a little easy, the fight begins. And boy, oh boy, are you going to have a hard time facing this guy for the first time. Being resistant to all types of attacks except blunt force, you will even wonder if you got into this fight sooner than you should. This is not the case however, as I mentioned before, as it hardly takes any damage other than clubs and clubs.
How to fight and beat Bonemass.
Bonemass summons many minions in the form of smaller versions of him, alongside huge AOE toxic attacks with a fairly large radius. Being overwhelmed by his lackeys, trying to avoid those death puddles while avoiding his normal attacks, rest assured that you will be constantly running low on stamina. With all of that in mind, now let's move on to how you can actually deal with him.
First of all, keep a lot of Poison Resistance Meads. You will need it. With that said and done, you now have two options here, based on my personal experience with him. Either you take the “normal” route or the easy “cheese” alternative. Whichever one you choose, both are effective in their own ways.
The first is how I beat him for the first time as well. You need one of two key things. The Stag-breaking hammer or Iron sledge. While the Stagbreaker hammer is rather easy to build, the Iron Sledge requires special items to be obtained beforehand, like the Ymir Eti you can find and buy from the merchant. Both are worth it, so be sure to craft them before the fight.
Continue the fight. Whenever there are no minions around, attack him as much as possible, supporting his attacks. Try to swing back and forth while trading blows, to regain your stamina and heal any poison that has accumulated with his skills. As he summons little guys to the field, start focusing on them with the AOE attack from your hammers. Don't try to kill them all at once or hit the Bonemass next to them, you don't have to. Be patient and wait for them to regroup. Hit once, rinse and repeat as many times as needed, don't chase them to finish them. Once they're all gone, start mauling again in Bonemass. It's pretty much the fight loop, so repeat until he's dead.
In case you want to avoid all of that hassle, Bonemass can be cheesy quite easily, leading us to the 2nd method you can use for this fight. Find a large tree and start laying floor tiles in a place it can't reach, above its head. Create a "mini" base there, with a workbench and a few walls with a few windows to be able to aim at it. You see where this is going ...
Once your little shed is done, bring it to this space, aim at it with your bow and start hailing Frost arrows against him, because they are the only ones who will hurt him a little. Whenever you run out of it, interact with your bench and just do as much as you need to complete the battle. Bonemass won't be able to react to anything in this compromise at all, as he can't reach you with any of his attacks. It can be annoying that way, and unsatisfactory as a first method, but it's definitely an easy way to get rid of it. Bonemass drops the Wishbone after he is defeated, leaving you to cultivate silver with an extremely simple and effective way, found here in this article.
Hope I helped you with these guidelines, so be sure to claim the Bonemass Trophy and get ready for the next biome.
Valheim is now available via Steam Early Access.