Deckard Cain, also known as Cain the Elder, is the last living human in the line of Horadric mages. Appearing in all of the Diablo games, Cain provides the player with valuable advice for many quests, and it is he who initiates the Archbishop Lazarus and Diablo quests in Diablo I, as well as numerous quests in Diablo II. Cain, in both games, can identify items for a charge (or for free if rescued by the player in Diablo II), and serves as a town elder throughout the events of Diablo I. He is descended from Jered Cain, who imprisoned Diablo two-hundred years before, and is schooled in the most obscure lore and history of the arcane. 
As of Diablo II, Cain is the only known survivor of Tristram's destruction, save the Dark Wanderer himself. Cain, rather than being killed by the demons, was left in a cage near the well in the center of town to die. In Diablo II's Search for Cain quest, Cain is rescued by the player, and afterward follows the player through each of the game's Acts. Griswold, now a reanimated monstrosity, was corrupted by Andariel herself and attempts to prevent Cain's rescue. Once Cain has been rescued by the hero, he will identify items free of charge. If the player neglects to rescue Cain, the rogues will do so after the Sisters to the Slaughter quest and the player must pay 100 gold for each item identified, though he will still follow the player through each Act.
Deckard Cain returns in Diablo III. Cain's journal is published as lore. His journal reveals that while Cain dreamt of being the last of the Horadrim, he is in fact not. It tells the events of Diablo and Diablo II in an abbreviated form and suggests numerous times that Cain was an elder and lorekeeper from Tristram, without much prior knowledge of the outside world - a stark contrast to the well-versed and knowledgable "last of the Horadrim" loremaster of Diablo and Diablo II. It is also strongly implied that Cain had no previous knowledge of the Worldstone prior to the events of the Diablo II ending.
It is unknown whether Cain lied when he presented himself as "the last of the Horadrim", and his reasons for doing so, that he had given himself a self assuming title, instead of what would be his proper title 'Last of the Horadrim in Tristram' or suffers from (possibly age-induced) dementia or Alzheimer's. The fact that the Archangel Tyrael also refers to him as the "Last of the Horadrim" further clouds the issue.
This section contains facts and trivia relevant to this article
- A common nickname for Cain on Battle.net is "Dickard", usually referenced when a player goes to town for his or her items to be identified.
- Blizzard released a song with Deckard Cain rapping. Listen to it here.
- Akara. "Quest:Search for Cain." Diablo II.
|Diablo III NPCs|
|Act I||Arghus the Collector • Bron the Barkeep • Brother Malachi the Healer • Captain Rumford • Deckard Cain • Ferryman • Haedrig Eamon • Lachdanan's Ghost • Leah • Mayor Holus • Radek the Fence • Tashun the Miner|
|Diablo II NPCs|
|Act I||Akara • Charsi • Deckard Cain • Flavie • Gheed • Kashya • Warriv|
|Act II||Atma • Deckard Cain • Drognan • Elzix • Fara • Geglash • Greiz • Jerhyn • Kaelan • Lysander • Meshif • Tyrael • Warriv|
|Act III||Alkor • Asheara • Deckard Cain • Hratli • Meshif • Natalya • Ormus • Dark Wanderer|
|Act IV||Deckard Cain • Hadriel • Halbu • Izual • Jamella • Tyrael|
|Act V||Anya • Deckard Cain • Larzuk • Malah • Nihlathak • Qual-Kehk • Tyrael|
|Diablo I NPCs|
|Diablo I||Adria • Deckard Cain • Farnham • Gillian • Griswold • Kael Rills • Ogden • Pepin • Wirt|
|Hellfire||Celia • Complete Nut • Lester|