Uber bosses are empowered versions of familiar act bosses that you can only reach through Infernal Machines. They drop the organs for the Hellfire Amulet – the amulet that grants an extra passive skill of your class – and for the Hellfire Ring. By the end you will know where the machines drop, which Torment level pays off and how to clear every realm safely.
At a Glance: the Loop
- Start an Adventure Mode game on Torment I or higher.
- Kill the four Keywardens in Acts I to IV. Each one always drops the same machine type.
- Break the boarded-up door next to the healer in New Tristram and activate the machines inside.
- Defeat the uber bosses in each realm and collect the organs.
- Buy the design from Squirt the Peddler in Act II for 5,000,000 gold.
- Craft the amulet at the Jeweler: one organ from each of the four realms, 10 Forgotten Souls, 50,000 gold.
The Four Keywardens
Each Keywarden spawns in a fixed zone and always carries the same machine:
- Act I – Odeg, Fields of Misery: Infernal Machine of Regret
- Act II – Sokahr, Dahlgur Oasis: Infernal Machine of Putridness
- Act III – Xah'Rith, Stonefort: Infernal Machine of Terror
- Act IV – Nekarat, Gardens of Hope 2nd Tier: Infernal Machine of Fright
They do not spawn on Normal through Master. Since patch 2.4.0 an arrow points you to them as soon as you enter their zone. The machines are account bound and can be passed to other heroes through your stash. In a group they only drop for players in the same area – stay together for the kill.
Machine Drops by Torment Level
Since patch 2.4.2, each Keywarden kill drops:
- Torment I: 50% chance for one machine
- Torment II: 75% chance for one machine
- Torment III: 90% chance for one machine
- Torment IV: 1 machine guaranteed
- Torment V–VIII: 1 guaranteed, plus 10 / 20 / 30 / 40% for a second
- Torment IX–XIII: 1 guaranteed, plus 50 / 60 / 70 / 80 / 90% for a second
- Torment XIV: 2 guaranteed, 25% for a third
- Torment XV: 2 guaranteed, 75% for a third
- Torment XVI: 3 guaranteed, 25% for a fourth
On Torment XVI a Keywarden yields 3.25 machines on average – more than three times as many as on Torment IV.
The Heretic's Abode: Activating the Machines
The machines only work in a hidden room in New Tristram (Act I). The item tooltip calls it a "tainted abode"; players know it as the Heretic's Abode.
- In New Tristram, go to Brother Malachi the Healer – heart icon on the minimap, near the Mystic.
- Next to him is a house with a boarded-up door. Attack it with any skill until it breaks.
- Activate a machine inside. It is consumed and opens a red portal to the matching realm.
The machines are marked "(Torment Only)" and only work from Torment I. Your game's difficulty also decides how many organs drop inside the realm.
The Four Realms and Their Bosses
Loot only drops once every boss in a realm is dead – the order does not matter. With a full set these fights are no big hurdle at level 70.
Realm of Regret – Skeleton King & Maghda
The King of the Dead teleports in as a wraith, summons skeletons and winds up a spinning attack – its first hit is the dangerous one. Maghda, The Merciless Witch, drops arcane sentries with strong beams. Burn the Skeleton King first; if Maghda becomes untouchable, kill her summoned helpers. Drop: Leoric's Regret.
Realm of Putridness – Ghom & Rakanoth
Ghom, The Foul Desecrator, spreads poison clouds and slimes – stay out of the clouds and kite him slowly around his boss room. Rakanoth, The Vile Executioner, is the real threat: his teleport strike reaches you at range and can one-shot a poorly geared hero, especially from behind. Kill him first. Drop: Vial of Putridness.
Realm of Terror – Zoltun Kulle & Siegebreaker
Zoltun Kulle, The Undying One, throws fireballs and brings boulders down from the ceiling; his Slow Time bubbles are especially strong in the uber version – leave them immediately. The Siegebreaker Assault Beast, The Savage Behemoth, charges distant targets and grabs heroes close to it. Keep your distance. Drop: Idol of Terror.
Realm of Fright – Diablo
At 75% and 50% health, Diablo – the Soul of Evil – stuns every hero and summons one random uber boss from the other realms each time. Dodge the fire and lightning and kill each new boss before you damage Diablo further – otherwise you fight three enemies at once. Drop: Heart of Fright.
Organ Drops by Torment Level
Each completed realm drops:
- Torment I: 1 organ
- Torment II–VI: 1 organ, plus 10 / 25 / 50 / 75 / 90% for a second
- Torment VII: 2 organs guaranteed
- Torment VIII–XII: 2 organs, plus 10 / 25 / 50 / 75 / 90% for a third
- Torment XIII: 3 organs guaranteed
- Torment XIV: 3 organs, 25% for a fourth
- Torment XV: 3 organs, 75% for a fourth
- Torment XVI: 4 organs guaranteed
Quick math: on Torment XVI the four Keywardens yield 3.25 machines of each type on average, each worth 4 organs – roughly 13 organs per realm, enough for about 13 amulets. In a group, every member usually gets their own organs.
Crafting the Hellfire Amulet
Buy the Design: Hellfire Amulet from Squirt the Peddler in the Hidden Camp in Act II for a one-time 5,000,000 gold. Your Jeweler learns it at rank 12 (Sovereign). Each amulet then costs:
- 1 organ from each of the four realms
- 10 Forgotten Souls
- 50,000 gold
When crafting you pick Strength, Dexterity or Intelligence as the main stat – there is no Vitality version. The Hellfire Amulet rolls:
- +626–750 of the chosen main stat
- a guaranteed socket (since patch 2.3.0)
- a random passive skill of your class
- three additional random magic properties
It is account bound and has no level requirement. The passive always comes from the class that crafts it and cannot be rerolled – for a different passive you need a new amulet. The amulet can roll Ancient (10% chance) and – after you have cleared a solo Greater Rift 70 – Primal at 0.25%.
Is the Amulet Worth It?
It effectively gives you a fifth passive skill. In strong builds, however, the neck slot usually holds Squirt's Necklace, The Flavor of Time or The Traveler's Pledge; next to those, the Hellfire Amulet is a niche pick. It stays interesting for supports in group speed runs. Plan for several attempts – the passive you want rarely shows up on the first try.
The Hellfire Ring: a Leveling Tool Now
The Hellfire Ring uses the same four organs and 50,000 gold but no Forgotten Souls; its design is also sold by Squirt. It offers:
- +45% experience – only 4.5% at level 70
- a chance on hit to engulf the ground in lava (200% weapon damage per second for 6 seconds)
- five additional random properties, rolled for your class
With no level requirement it is mainly a leveling ring for new heroes; at level 70 the bonus is barely noticeable.
Season Journey and Rewards
The Season Journey introduces the system (as of Season 39 – Blizzard may change objectives when Season 40 starts on October 2, 2026):
- Kill the four Keywardens at level 70 on Torment IV or higher
- Defeat the bosses of the Realms of Regret and Putridness on Torment I or higher
- Defeat the bosses of the Realms of Terror and Fright on Torment X or higher
- Craft a Hellfire Amulet in a later chapter
See the Season Starter Guide and the Season 40 page for more. Besides organs, the uber bosses drop gold and extra items; Diablo can also drop the Star Pauldrons – a pure transmog shoulder piece.
Common Mistakes
- Farming on Torment I: only a 50% machine chance and one organ per realm. From Torment XIII, three organs are guaranteed.
- Looking for keys: they belong to the old system – Keywardens drop finished machines.
- Mixing up Terror and Fright: Terror comes from Xah'Rith (Act III), Fright from Nekarat (Act IV) and leads to Diablo.
- Bursting Diablo too fast: push through 75% and 50% at once and you face several bosses together.
- Farming unevenly: every amulet needs all four organs – your scarcest organ decides how many amulets you can craft.
FAQ
Do I still need keys for the Infernal Machines?
No. Since patch 2.3.0, Keywardens drop the machines directly; crafting them at the Blacksmith no longer exists.
Where do I use the Infernal Machines?
In New Tristram: break the boarded-up door next to the healer (heart icon on the minimap) and activate the machine in the room behind it – Torment I or higher.
Which Torment level is best for uber bosses?
The highest one you can play safely. From Torment IV a machine always drops, from Torment XIII three organs per realm are guaranteed, and Torment XVI gives four.
How much does a Hellfire Amulet cost?
A one-time 5,000,000 gold for the design. Each amulet then costs one organ from each of the four realms, 10 Forgotten Souls and 50,000 gold.
Can I reroll the Hellfire Amulet's passive?
No. The passive is fixed when you craft the amulet; for a different one you need to craft a new amulet.
Is the Hellfire Ring still worth crafting?
For leveling new heroes, yes: +45% experience with no level requirement. At level 70 the bonus shrinks to 4.5%.
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