Reaper of Souls is the first expansion for Diablo III, Blizzard announced at Gamescom today.
The expansion introduces a new campaign act that will see players track and battle the Angel of Death in the new setting of Westmarch.
It also adds a new melee-focused Crusader class as well as Loot Run and Nephalem Trials modes, raises the level cap to 70, and extensively rebalances loot drops.
The Crusader is a mid-range melee character similar to the Paladin from Diablo II, whose skills include shield bash, a blinding shield flare, and area effect powers fist of the heavens and falling sword.
"Driven by a centuries-long quest to cleanse the corruption blighting their beloved Zakarum faith, Crusaders are warriors of righteousness who have been hardened through relentless, brutal combat with the foul evils plaguing eastern Sanctuary," said Blizzard.
"In addition to wearing immensely heavy armor and wielding a wide range of cruel and punishing weapons, this new playable class in Reaper of Souls uses battle magic to strengthen allies and weaken foes.
"A natural walking tank, the Crusader adds power and versatility to any party of adventurers," it added.
Reaper of Souls has Diablo imprisoned in the Black Soulstone, but Malthael - the fallen Archangel of Wisdom and now Angel of Death - has seized it.
It is up to players to track down Malthael and prevent him from unleashing its terrible power on the world.
There's no release date yet, and it's not yet clear whether Reaper of Souls is coming to the console as well as PC and Mac versions of Diablo III.