The new, fifth act of the story sees Malthael - once the Archangel of Wisdom, now the Archangel of Death - take possession of the Black Soulstone, using the powers of the prime evils to command a legion of death angels in an effort to cleanse Sanctuary of the last demonic presence it hosts - Humankind, the illicit children of Angels and Demons.
Reaper of Souls adds a fifth act to the game, beginning in the gothic city of Westmarch and eventually expanding to its surrounding environments and beyond. Malthael, the long-missing archangel of Wisdom, now the Archangel of Death, appears on Sanctuary bent on the elimination of all mankind, seeing them as the only remaining trace of a demonic presence that must be purged in order to bring resolution to the Eternal Conflict. Using the power of the Black Soulstone, an artefact which contains all of the Prime Evils - Diablo, Mephisto, Baal - and Azmodan, Malthael begins his assault with a mass reaping of human souls in the decadent city of Westmarch.
The Crusader is a mid-ranged melee class who will use shields, flails, and mid-ranged spells in combat. The class is directly inspired by Diablo II's Paladin, and hails from the same Order of Zakarum.
The level cap has been increased to 70 and all the heroes from Diablo III can learn new skills and abilities along the way.
Adjustments to the loot system mean players will get fewer drops overall, but the quality of the drops are better. The chance that the legendary drops the player receives will be aimed specifically towards their class has also increased.
A subsequent patch introduced a new tier of items, Ancient Items, which are improved versions of Legendary and Set-piece gear that are able to roll higher stats. Ancient items are much rarer than their Legendary and Set-piece counterparts, and are designed primarily to give players who have already acquired the loot they need for their builds another tier of progression to aim toward.
The Mystic has been added as the third artisan of the game. The Mystic is able to transmogrify items to change their appearance. She is also able to enchant items, which at the cost of gold and materials, allows the player to have one aspect of a piece of equipment changed to one of a few new choices presented. The changed stat can be further changed if the player desires, at an increased gold cost.
Once completing the campaign on one character, Adventure Mode opens for the account. Eschewing the story elements of Diablo 3, Adventure Mode allows players to take on randomized missions in any Act setting of the game. Completing these bounties give bonus experience, loot and gold, as well as Rift Keystone Fragments, which allow players to enter large, randomized dungeons called Nephalem Rifts for even more loot and gold. Inside of Nephalem Rifts, players are more likely to earn legendary loot. A separate form of Rift entitled Great Rifts are unlocked using Greater Rift Keys, and provide a scaling challenge that becomes harder the more you invest in the key by ranking it up after successful clears. From these Greater Rifts, which must be completed under a set time limit, the player can loot Legendary Gems that have extremely powerful primary and secondary effects, often augmenting or empowering character builds in significant ways. Some new zones are only accessible inside of Rifts, including the Cesspools and, in a future patch, the Ruins of Sescheron - the Barbarian city featured in the Diablo II: Lord of Destruction cinematic.
Leaderboards and Seasons
Subsequent patches to Reaper of Souls included the addition of Leaderboards which track players progress as they complete higher ranks of the Greater Rift system. Solo and group endeavours are tracked, and leaderboards can also be filtered by class. Seasons are Diablo III's answer to Diablo II's Ladder system in that they are timed leagues in which people race to clear content, earn max level and become competitive in the Greater Rift rankings. Special seasonal achievements are also available to encourage different playstyles, and rewards like unique transmogrifications and banner decorations. New legendary and set-piece items are also introduced with each season, and these are exclusive to the season until it ends, when they become available in the non-seasonal item pool.
When a Season ends, seasonal characters are merged into the non-seasonal mode along with the contents of their inventories and Seasonal stash. Any progress made in leveling up Artisans is also carried over, and Paragon experience points will also be added to the non-seasonal paragon experience pool.