To prevent this from happening what you should do is use three Infernal Machines to open all three portals at the same time. the same portal as before? Well that is hardly ideal since you already killed that boss pair and you don't need that organ again! When you start up a new game session and you use your second Infernal Machine, what if it randomly opens. If you leave the game for the day (or a meal) and you end your game session that one portal you opened will close. You can enter that portal fight the uber bosses and (hopefully) get the organ piece you need. When you use your first Infernal Machine to open one of the three portals it will randomly open one of the three possible portals. To be fair you can use one machine to open one of the three portals that transport you to a demonic realm, but it does not make sense to do that. Once crafted the Infernal Machine takes up one item slot in your inventory (the size of a ring). The Infernal Machine costs 12,000 gold to craft. Right click on the plans to teach them to blacksmith and the Infernal Machine will appear on the Weapons tab under the new Portal Device heading (look under P).

Once you gather all three keys and the crafting plans you can then take them all to the blacksmith. The Keywardens in the first three acts drop a key, and the Keywarden that appears in Act IV drops the crafting plan for the Infernal Machine.įor more information on the Keywardens and the drop rates of the keys click here. There are four Keywardens and each one can be found in one of the four acts in Diablo III.

To begin your journey all you need to do is find and kill a Keywarden.

Diablo 3 infernal machine keys