By Jason Parker
Diablo 4鈥檚 updated boss ladder system means you鈥檒l no doubt want to farm boss lair keys in Season 9. Season 8 improved this system by a massive amount, making it so people actually group to do boss fights again. If someone joins your group and doesn’t have a boss lair key, they can鈥檛 get any loot, so it doesn鈥檛 matter if they show up to the party or not. It鈥檚 a much better system, but now there鈥檚 a new question.If you want to farm boss lair keys in Diablo 4, you want to do it efficiently. If you鈥檙e looking to do that, I鈥檓 here to help. I鈥檒l go over where the best places to farm ingredients will be below, but do take this with a grain of salt. If you prefer doing specific types of content over the others, by all means, do something else; as long as it drops the ingredients you need.Where to farm for each boss lair key in Diablo 4Each of the bosses in Diablo 4 needs specific materials to make boss lair keys, and so each one has activities you can farm to get what you need. The material costs, for the most part, are much lower, though you won鈥檛 be doing this until you鈥檝e reached Torment difficulty.Knowing which events to complete and which bosses to farm is important in D4 (Image via Blizzard Entertainment)Below, we鈥檒l cover how many of the item you need in brackets, and then what activity you should be completing to farm the boss lair key in Diablo 4. This is something that can definitely take some time, so I recommend a powerful class, or at least, something you鈥檙e comfortable with. As another note, the Seasonal Journey chests can often give you tons of boss lair key materials, so keep that in mind as well.Varshan (12x Malignant Heart): Tree of Whispers BountiesGrigoire (12x Living Steel): Take part in Helltides and open Tortured Gifts throughout the zonesLord Zir (12x Exquisite Blood): Farm Blood Maiden in HelltidesThe Beast in the Ice (12x Distilled Fear): Complete Nightmare DungeonsUrivar (12x Judicator鈥檚 Mask): Farm UndercityDuriel (3x Shards of Agony): Farm Varshan and GrigoireAndariel (3x Pincushioned Doll): Farm The Beast in the Ice and Lord ZirHarbinger of Hatred (3x Abhorrent Heart): Farm UrivarBelial (2x Betrayer鈥檚 Husk): Farm Belial鈥檚 Ambush after opening boss lair chests.Belial is an interesting one, though. Out of all the boss lair keys to farm, his is the most frustrating. You need to farm Belial鈥檚 Ambushes. Occasionally after opening a boss lair chest, Belial will show up and ambush you/your group. Defeating this has a chance to give you Betrayer鈥檚 Husks.The Initiate Tier (Varshan, Grigoire, Zir, Beast in the Ice, Urivar) can now also drop Stygian Stones. You can break these down at the Alchemist to make them into Greater Lair Boss materials (Duriel, Andariel, Harbinger). This can help make farming much easier, in the long run. Again, as a reminder, you can only farm these on Torment or higher, so keep that in mind before you start the journey. Bosses have their own Unique loot tables as well, that gets updated each and every season with the new uniques that get added to the game.Check out our other Diablo 4 guides and featuresDiablo 4 Season 9: All changes since the 2.3.0 PTRDiablo 4 Season 9: Escalating Nightmares mechanic, explainedDiablo 4 Season 9 Endgame tier list: Best builds for Pit push and bossingDiablo 4 Season 9: All Horadric Jewels (known so far)