The setting of Diablo is the town of Tristram, the de facto capital of the Kingdom of Khanduras on the world of Sanctuary. The actual fighting takes place beneath the town in a maze of dungeons, catacombs, and caves that lead into the depths of Hell.
The plot of the original Diablo game centers around a player character undertaking a series of quests to free Tristram from Hell-spawned evil, descending through twelve levels of dungeons, catacombs, and caves into Hell itself (the final four levels), where the player battles the title character, Diablo, Lord of Terror — one of the seven "Evils" (devils) who once ruled Hell.
Diablo offers three character classes and the Hellfire expansion offers three more. Players can play as Warriors, Rogues (archers), or Sorcerers. Each class has its own place in the game's history, and all three classes are seen as NPCs in the sequel. All three classes have the same general skills and access to the same spells. Each of them has a class-specific skill (Item Repair, Trap Disarm, and Staff Recharge, respectively) that has as many drawbacks as benefits, except for Trap Disarm.
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