Guide to the Infernal Machine & Hellfire Rings

The Infernal Machine is a device that once crafted opens a portal to another realm where you can face off against Uber versions of Diablo 3 bosses. It is also a required step in crafting the Hellfire Ring. Click any topic to jump to that part of the guide.

Getting parts for the Infernal Machine

Realm of Uber Bosses

Hellfire Ring & Amulet

Crafting the Hellfire Ring & Ring Stats

Extra Information

Drop Rates

Keys and organs can only drop on Torment 1 or higher. Below is the drop rate per Torment level.

Torment I: 25%
Torment II: 28%
Torment III: 33%
Torment IV: 38%
Torment V: 43%
Torment VI: 50%

Infernal Machine Plan

The plan is a guaranteed drop off any of the keywardens

Other general information

The Keywardens are a guaranteed spawn in each game but may spawn anywhere on the specific maps.
You can have more than 1 key at a time.
A new machine must be built each time you want to fight another pair of bosses.

Key of Bones- Odeg the Keywarden

The first Keywarden is found anywhere in the Fields of Misery of Act I. Odeg has the Molten and Jailer affixes and a fire attack that shoots three balls of fire. His regular attack is a ranged spear throw. Just remember that when Odeg dies he will leave behind a exploding ball of fire that can kill you!
Key of Gluttony - Sokahr the Keywarden The second Keywarden is found anywhere in the Dahlgur Oasis of Act II. Sokahr is a very anti-ranged monster as he has Missile Dampening, Mortar and Electrified as base abilities. His non-special attack is a spin attack that does damage to all those near him.
Key of War- Xah'Rith the Keywarden The third Keywarden is found anywhere in the Stonefort of Act III. He has the ability to teleport and periodically rain down corpses that explode causing a fair amount of damage while also creating a small area of ice that slows you substantially.
Key of Evil - Nekarat the Keywarden The last Keywarden drops the Infernal Machine Plan. He is found anywhere in the Silver Spire Level 1 of Act IV. Jailer, Knockback and Nightmarish are his main affixes along with a curse that reduces healing effects by 75%. Nekarat also has the ability to create a large firey spell on the ground that deals damage to anyone inside of it. Note: He has a small chance to drop any of the other keys from a Keywarden.
Entrance to the Infernal Machine Once you have all the materials you need to visit the blacksmith to create your Infernal Machine. After that it's time to enter the Realm of Chaos. The entrance can only be found on the last quest of Act I, "Return to New Tristram". Simply make your way to the healer in New Tristram and attack the door behind him. Once inside all you need to do is right click the Infernal Machine item in your inventory.

The first Keywarden is found anywhere in the Fields of Misery of Act I. Odeg has the Molten and Jailer affixes and a fire attack that shoots three balls of fire. His regular attack is a ranged spear throw. Just remember that when Odeg dies he will leave behind a exploding ball of fire that can kill you!

Key of Gluttony - Sokahr the Keywarden

The second Keywarden is found anywhere in the Dahlgur Oasis of Act II. Sokahr is a very anti-ranged monster as he has Missile Dampening, Mortar and Electrified as base abilities. His non-special attack is a spin attack that does damage to all those near him.

Key of War- Xah'Rith the Keywarden

The third Keywarden is found anywhere in the Stonefort of Act III. He has the ability to teleport and periodically rain down corpses that explode causing a fair amount of damage while also creating a small area of ice that slows you substantially.

Key of Evil - Nekarat the Keywarden

The last Keywarden drops the Infernal Machine Plan. He is found anywhere in the Silver Spire Level 1 of Act IV. Jailer, Knockback and Nightmarish are his main affixes along with a curse that reduces healing effects by 75%. Nekarat also has the ability to create a large firey spell on the ground that deals damage to anyone inside of it.

Note: He has a small chance to drop any of the other keys from a Keywarden.

Entrance to the Infernal Machine

Once you have all the materials you need to visit the blacksmith to create your Infernal Machine. After that it's time to enter the Realm of Chaos. The entrance can only be found on the last quest of Act I, "Return to New Tristram". Simply make your way to the healer in New Tristram and attack the door behind him. Once inside all you need to do is right click the Infernal Machine item in your inventory.

Uber Ghom & Rakanoth - The Realm of Chaos

In my opinion this is the easiest of all the Uber bosses. There is no changes to these bosses that I noticed and it's basically just fighting both Ghom and Rakanoth at once. In all my runs I killed Ghom first as I found it to be quite annoying having the entire room fill up with his poison clouds. This fight is easy enough where anyone with decent gear should not have any trouble.

Uber Siegebreaker & Zoltun Kulle - The Realm of Turmoil

This match up is a little bit harder than Ghom & Rakanoth due to the fact Zoltun Kulle has a lot of abilities that interfere with the fight. Getting caught in his slow time bubbles while Siegebreaker chases you down only to be hit by a Meteor from Zoltun Kulle is not fun. I decided to get rid of Zoltun Kulle first as his abilities have the biggest impact on the fight. I just had to make sure to dodge Siegebreakers charge and the fight was simple once Zoltun Kulle died.

Uber Skeleton King & Maghda - The Realm of Discord

This was the hardest fight for me and it is the only fight that changes the actual mechanics of the bosses. You have no choice but to kill the Skeleton King first because when Maghda hits 75% hp she will put a invincibility shield on herself until every single monster including the Skeleton King is dead. If that wasn't bad enough you have to deal with constant Arcane Enchanted beams everywhere, as the Skeleton King keeps raising Skeletons and Maghda shoots her bug cloud at you. Have fun!

Video of Uber Diablo

Crafting the Hellfire Ring & Ring Stats

Quick facts about the ring:

Crafting cost of Ring - Heart of Evil, Idol of Terror, Leoric's Regret, Vial of Putridness and 50,000 Gold.
Crafting cost of Amulet- Heart of Evil, Idol of Terror, Leoric's Regret, Vial of Putridness, 10 Forgotten Souls and 50,000 Gold.
Heart of Evil is acquired by defeating Uber Diablo .
Idol of Terror is acquired by defeating Zoltun Kulle & Siegebreaker.
Leoric's Regret is acquired by defeating Skeleton King & Maghda.
Vial of Putridness is acquired by defeating Uber Ghom and Rakanoth.
The plan is bought for 5 million gold from Squirt the Peddler in Act II.
All the items required to craft the ring drop from the Uber Bosses.
Act 4 Keywarden has a chance to drop any key.
Keys and Organs only drop on Torment 1 difficulty or higher.
You can choose either Dexterity, Strength, Vitality or Intelligence for the ring or amulets main stat.