The Infernal Machine is an end game quest feature introduced in the v1.0.5 patch. The feature was teased pre-patch in several developer blogs and interviews, which gave only vague details and hints about the content and creation of the feature.
The first word of the Infernal Machine came in a Patch 1.0.5 Sneak Peek developer blog post on September 13, 2012. The brief quote is below:
The Infernal Machine is a device that will allow level-60 players to battle “uber” versions of some of Sanctuary’s most nefarious bosses. While the rewards for defeating these bosses will be great, some assembly is required.
- To unlock the Infernal Machine players will have to gather ingredients from all four acts, so it will presumably not be a short and easy assembly process. (Apparently even longer and more involved than Diablo 2′s Pandemonium Event.)
- The Infernal Machine level has “a completely new architecture” (tileset?), but no new bosses or monsters. (Presumably the “uber” bosses will be palette shifted and have some new abilities, but we’ll wait for D3X for entirely new monsters.)
- The Infernal Machine reward is a new Legendary ring only available from this quest. The biggest news is that it will Bind on Account. So no trading or selling or gifting, but you can use it with other characters on your account.
Full details will not be revealed until patch v1.0.5 is released. That patch currently has no ETA.