Infernal Machine

The Infernal Machine is a device in Diablo III used to open a portal analogous to the Über Tristram event in Diablo II. Once inside, the player can battle two Über versions of Act Uniques for an opportunity to collect organs to create a Hellfire Ring or (as of Patch 2.1) a Hellfire Amulet.

''Clashing gears and foul magic grind away within this cursed construct. Its malevolent passage can only be unleashed inside a house of the damned.''

Acquisition
The Machines drop from Keywardens on any Torment difficulty. At level 60, each of them has a chance to drop a single Infernal Machine. At level 70, each drops only one type (name of the Keywarden shows which machine they drop, and which material can be gained in result):
 * Odeg the Keywarden in Act I - Fields of Misery (Infernal Machine of Regret)
 * Sokahr the Keywarden in Act II - Dahlgur Oasis (Infernal Machine of Putridness)
 * Xah'Rith the Keywarden in Act III - Stonefort (Infernal Machine of Terror)
 * Nekarat the Keywarden in Act IV - Gardens of Hope Second Tier (Infernal Machine of Fright)

The devices are account bound. Drop chances increase with difficulty (see Torment for exact percentages): starting at T4, it reaches 100%, with higher difficulties giving a chance for a second Machine to drop. At T13, there is a 90% chance for the second Machine to drop.

After the machines have been collected (it is advised to collect at least 3, or 4 different ones at level 70), they can only be activated in a cellar in New Tristram known as the Heretic's Abode in Adventure mode. The entrance is located next to Brother Malachi the Healer, and can be opened by using an attack on the door. Activating the device will create a red portal which leads to a realm where a pair of Über Bosses must be defeated for a chance to drop one of three organs. Activating the device will also destroy it, so the player will need to kill Keywardens again to get another one. Note that neither of the devices are guaranteed to drop, and level 60 and 70 Machines are not interchangeable. On level 60, you need three devices, on level 70, you will require four, and they must all be of different types. On level 60, each used machine opens a randomly selected different portal; to open 3 different ones, you need to use 3 machines in the same game. As on level 60, each device opens a random portal, if you activate three devices in one game, you are guaranteed to receive one portal of each type. On level 70, there is a separate machine depending on which set of Uber bosses you wish to fight (see below).

You may only activate the device on Torment I difficulty or higher.

There are four sets of Uber bosses, depending on which portal you open (the level 60 Infernal Machine opens a random portal, but using three machines in one game will open three different ones). See above for details on how to open these portals. The portals will have second names in descriptions, which match the crafting ingredient they can potentially lead to.


 * Realm of Discord (Realm of Regret): the empowered Skeleton King and the empowered Maghda, drop Writhing Spine (60) or Leoric's Regret (70), opened with the Infernal Machine of Regret.


 * Realm of Turmoil (Realm of Terror): the empowered Zoltun Kulle and the empowered Siegebreaker, drop Vengeful Eye (60) or Idol of Terror (70), opened with the Infernal Machine of Terror.


 * Realm of Chaos (Realm of Putridness): the empowered Rakanoth and the empowered Ghom, drop Devil's Fang (60) or Vial of Putridness (70), opened with the Infernal Machine of Putridness.


 * Realm of Fright: Level 70 only, the empowered  who also summons other bosses one by one, drops Heart of Fright, opened with the Infernal Machine of Fright.

Realms of Pure Evil are fixed for boss pairs: Leoric and Maghda in the Royal Crypts, Ghom and Rakanoth in the Larder, or Siegebreaker and Zoltun Kulle in the Edge of the Abyss. On level 70, there is a fourth portal, where you will fight Shadow of Diablo in the Realm of Terror, along with two additional bosses.

Loot is only awarded once the player defeats all bosses (does not matter in which order).

The Rewards
For successfully defeating a boss pair, players will be rewarded with extra items and gold. In addition, they will also have a chance to harvest the crafting ingredients from each of their fallen foes, which can be used to create the Hellfire Ring or the Hellfire Amulet. Crafting ingredients will drop the same for all party members. If one player gets an ingredient, all players do. Drop rate scales with difficulty, up to 100% (PC only) at Torment VI. If difficulty is decreased to Master or lower, the drop rate becomes 0% automatically.


 * The Writhing Spine (Leoric's Regret on level 70), which drops from King Leoric or Maghda.
 * The Devil's Fang (Vial of Putridness on level 70), which drops from Ghom or Rakanoth.
 * The Vengeful Eye (Idol of Terror on level 70), which drops from Siegebreaker or Zoltun Kulle.
 * The Heart of Evil, level 70 only, which drops from Shadow of Diablo.

With the three (four for the level 70 variant) pieces mentioned above and 2,000,000 (5,000,000 for the level 70 plans) gold, buy the plan(s) from Squirt the Peddler. A level 10 Jeweler (or Armorer on consoles) can craft the basic Hellfire Ring for a fee of 50,000 gold, while a level 12 Jeweler/Armorer can make the upgraded Hellfire Ring and Hellfire Amulet, for the same fee of 50,000 gold.

Console Version
PS and XBox versions of the game have slight differences in the system: reduced gold costs of recipes (100,000 for both variants).

The Components
Prior to patch 2.3, both 60 and 70 versions of the Machine required a set of keys to craft. To craft the Infernal Machine, players first needed to collect all components from Keywardens. On consoles, the Key of Evil dropped from either Siegebreaker or Zoltun Kulle when using the Infernal Machine of War.
 * The Key of Destruction (Key of Bones on level 70)
 * The Key of Hate (Key of Gluttony on level 70)
 * The Key of Terror (Key of War on level 70)
 * The Blacksmithing Plans (and Key of Evil on level 70)

Devices could then be assembled in town at the Blacksmith. The Blacksmith would need to be level 10 (12 at 70) in order to learn the plans (sold by Squirt the Peddler, or dropped by Odeg the Keywarden), and required 12,000 gold (100,000 on 70) to forge the device in his furnaces.