At its core, Diablo III is a very different game than Diablo II – and that starts with not having to chug mana and rejuvenation potions after every fight (or even during them). Thanks to some brand new mechanics, your HP will be restored by touch-and-heal red orbs, and you won’t have to worry about lugging around a belt full of blue pots. Only the Witch Doctor uses the series’ traditional power source of mana. The Wizard fuels her magical attacks with Arcane Power, a quickly regenerating magical energy.
The not-so-magical classes have different means of casting their spells: the Barbarian relies on Fury, a use-it-or-lose-it resource that builds up by with each attack. The Monk, D3’s holy warrior, runs on Spirit. It gives him a defensive boost, and does not degrade over time. The most unique energy mechanic in D3 belongs to the Demon Hunter, who subsists on Discipline and Hatred. Hatred comes quickly to the Demon Hunter, allowing her to tear quickly into foes. Discipline, however, is harder to come by, and it powers her defensive abilities.