Diablo III picks up the story twenty years after the events of Diablo II. Mephisto, Diablo, and Baal have been defeated, but the Worldstone, which once shielded the inhabitants of the world of Sanctuary from the forces of both Heaven and Hell, has been destroyed, and evil once again stirs in Tristram. Playing as a hero from one of five distinct character classes, players will acquire powerful items, spells, and abilities as they explore new and familiar areas of Sanctuary and battle hordes of demons to safeguard the world from the horrors that have arisen.

The game takes place on Sanctuary, a world of dark fantasy. Unbeknownst to most of its inhabitants, Sanctuary was saved some twenty years ago from the demonic forces of the underworld by a few brave and powerful heroes. Most of those warriors who directly faced Hell's armies - and were fortunate enough to survive - went mad from their experiences. And most of the others have buried their haunted memories and pushed the horrors from their thoughts. In Diablo III, players will return to Sanctuary to confront evil in its many forms once again.