Gameplay
Gameplay is similar to that of previous titles in the Diablo franchise. The game is classified as a tactical adventure game that is played primarily using the mouse to direct the character with supplementary commands provided through the keyboard.
The proprietary engine incorporates Blizzard's custom in-house physics, a change from the original usage of Havok's physics engine, and features destructible environments with an in-game damage effect. The developers sought to make the game run on a wide range of systems without requiring DirectX 10. Diablo III uses a custom 3D game engine in order to present an overhead view to the player, in a somewhat similar way to the isometric view used in previous games in the series. Enemies utilize the 3D environment as well, in ways such as crawling up the side of a wall from below into the combat area.
As in Diablo II, multiplayer games are possible using Blizzard's Battle.net service, with many of the new features developed for StarCraft II also available in Diablo III. Players are also able to drop in and out of sessions of co-operative play with other players. Unlike its predecessor, Diablo III requires players to be connected to the internet constantly due to their DRM policy, even for single-player games.
An enhanced quest system, a random level generator, and a random encounter generator are used in order to ensure the game provides different experiences when replayed.
Unlike previous iterations, gold can be picked up merely by touching it, or coming within range, adjusted by gear, rather than having to manually pick it up. One of the new features intended to speed gameplay is that health orbs drop from enemies, replacing the need to have a potion bar, which itself is replaced by a skill bar that allows a player to assign quick bar buttons to skills and spells; previously, players could only assign two skills (one for each mouse button) and had to swap skills with the keyboard or mousewheel. Players can still assign specific attacks to mouse buttons.
Skill runes, another new feature, are skill modifiers that are unlocked as the player levels up. Unlike the socketable runes in Diablo II, skill runes are not items but instead provide options for enhancing skills, often completely changing the gameplay of each skill. For example, one skill rune for the Wizard's meteor ability reduces its arcane power cost, while another turns the meteor to ice, causing cold damage rather than fire.
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