For players aiming to farm Lair Bosses efficiently in Diablo 4 Season 10, the key lies in gathering boss materials first. Unfortunately, these materials aren't guaranteed drops, but there's a highly effective two-step farming strategy that maximizes your chances. By combining Helltides and the Kurast Undercity from Diablo 4 Items the Vessel of Hatred DLC, players can reliably stockpile every material needed for the Initiate, Greater, and even Exalted Lair Bosses.

The 9 Lair Bosses and Their Materials

Each of Diablo 4's Lair Bosses has a unique material required to open its reward chest after defeat. These are the key materials and their associated bosses:

Girgoire - Living Steel
Beast in the Ice - Distilled Fear
Echo of Varshan - Malignant Heart
Lord Zir - Exquisite Blood
Urivar (DLC Only) - Judicator's Mask
Duriel - Shard of Agony
Andariel - Pincushioned Doll
Harbinger of Hatred (DLC Only) - Abhorrent Heart
Belial, Lord of Lies - Betrayer's Husk

While the Initiate Lair Bosses (Girgoire, Zir, Varshan, Beast in the Ice, Urivar) are the most efficient for farming Diablo 4 materials, this route also gives a decent supply for Greater and Exalted Bosses-particularly Duriel, Andariel, and Belial.

Step 1: Farm Undercity Tributes from Helltides

The first half of this farming loop is all about Helltides-the dynamic, demon-filled world events that reset every hour. Helltides are packed with opportunities to earn Undercity Tributes, a currency required to amplify material drops from the Kurast Undercity dungeon.

Players should specifically focus on farming Tributes of Titans, as these increase the rewards from successful Undercity runs when you achieve Rank 1 completion. You can earn Tributes by:

Defeating Blood Maidens (summoned using Baneful Hearts)
Opening Helltide Chests
Completing Whispers within Helltides, then opening the Whisper Cache

It's a good idea to contribute Baneful Hearts during the Blood Maiden summoning ritual. This not only increases your personal Tribute drop chances but can also drop boss materials directly, making this stage a double-dip opportunity're farming both Tributes and materials simultaneously.

Step 2: Spend Tributes in the Kurast Undercity Dungeon

Once you've stocked up on Tributes of Titans, it's time to move into the Kurast Undercity, a dungeon accessible in the Vessel of Hatred DLC. Each Tribute of Titans you use increases the drop rate and quantity of Lair Boss materials earned at the end of a successful run.

Here's how to optimize your Undercity farming runs:

1. Activate a Tribute of Titans before starting each run.
2. Clear the dungeon quickly, focusing on elite packs and side objectives that increase end rewards.
3. Repeat the process until you've gathered enough materials for the boss you're targeting.

If you don't own the DLC, your best alternative is to stay in Helltides and repeatedly summon Blood Maidens using Baneful Hearts. This remains the most consistent non-DLC method of farming Initiate Boss materials in Season 10.

Step 3: Move Up the Lair Boss Ladder

Once you've reached your material goals, you can start summoning and defeating Initiate Lair Bosses. Each successful clear not only grants high-tier loot but also has a chance to drop Greater Lair Boss materials, letting you climb the ladder efficiently.

Here's the ideal farming progression path:

1. Farm Initiate Boss materials via Helltides and Undercity runs.
2. Defeat Initiate Bosses to earn Greater materials.
3. Challenge Greater Bosses (like Duriel and Andariel) for a chance at Belial's Betrayer's Husk, used for Exalted chests.

This structured approach ensures you're always progressing upward, never wasting time farming bosses without the materials to cheap d4 mats open their reward caches.