1. Summary
2. Background
3. Hype

Diablo III has a lot of elements pulled directly from the previous games in the series. Therefore, it would be more prudent to cover the background for the entire Diablo mythos rather than just Diablo III. After all, when everything is derived from the same set of characteristics, it matters not whether we are talking about Diablo II or III. It's all the same!

Diablo's story is a mixture of myths and gothic fantasy, and deserves recounting, starting with the first game. Possessing the body of the local king's son, Diablo twisted and manipulated the kingdom into weakening itself for his invasion. With an army of demons below the cathedral located in the destitute capital of Tristram, Diablo started to consolidate his power for an attack on the mortal realm. However, a hero managed to traverse the entirety of Diablo's vast underground lair and defeat him, shoving the stone that held the demon's soul into his forehead. Driven mad by the twisting corruption of Diablo, the hero set out to the east, gradually becoming more and more lost to the powers of hell as he went. Following in his wake were a collection of heroes from every walk - from necromancers to amazons - intent on destroying his evil once and for all. Diablo's journey turned out to be a quest to give the three Prime Evils of hell physical form in this world, and the heroes defeated all three: Mephisto, Lord of Hatred; Diablo, Lord of Terror; and finally Baal, Lord of Destruction. Diablo III takes place 20 years after the destruction of the Prime Evils, with evil once again seeping out into the world.

The most obvious parallel in the Diablo series is that of the War in Heaven present in Judeo-christian mythology. In this story, Lucifer is cast from heaven for attempting to usurp god's rule with a cadre of loyal angels. Upon his removal from heaven, he and his angels formed the core of Hell's armies, with Lucifer going by many different names, including Satan. In the apocalypse, Lucifer/Satan will supposedly rise up and lead his armies against heaven once more, forcing humans to choose a side: heaven or hell. In Diablo, this translates to the Prime Evils, who were trapped by the archangels of the High Heavens into three soulstones and cast down to earth. There the soulstone's power to contain Diablo gradually weakened, ending with him escaping his imprisonment and allowing him to free his brothers to corrupt this mortal world and bring about the apocalypse.

The three Prime Evils in Diablo are named after three representations of demonic figures in Judeo-christian mythology. The first, Diablo, is the Spanish word for devil, which makes the reference there very simple and straightforward. Baal is a term used throughout the Old Testament to refer to any god that was not Yahweh. It was used in a derogatory manner, and its connotation with evil, destruction, and falsehood has led it to be used in several settings to refer to an evil deity or demon. Mephisto is more recent, with origins in the classic myth of Faustus, a man whose interactions with devils put his soul on the line. Baal (as Bhaal) is notable in that it is the name of a deity in the Forgotten Realms setting, which spawned the classic Baldur's Gate RPGs (they revolve around his influence).

Along with the many references to demons and devils, the Diablo series pulls from the gothic style of literature and architecture to craft a dark and foreboding setting. The cathedral and the monastery in the first and second game both have very distinctive resemblances to the gothic architecture during medieval times. The story itself is insidious in its implication of evil, mysterious story, and overarching plot. It's greatly reminiscent of gothic classics, and the influence there is unmistakable.

The gameplay influence on the Diablo series is much more simple than the complex stylistic background. Diablo pulls the rogue-like formula and changes it so that it is much more approachable for your average Joe. Rather than being turn-based, having an ASCII interface, and forcing players to permanently die quite a bit, Diablo is action-packed, good-looking and simple to understand. However, leftovers from the transition, such as randomization of levels, shrines, unidentified equipment, and procedurally-generated equipment all make an appearance here. In a way, Diablo is the gateway drug into games like Nethack, Dwarf Fortress, or Crawl.