Book of Cain
Diablo III: Book of Cain, published by Insight Editions in 2011, is written as Deckard Cain's own journal: a history of Sanctuary, its creation, the Sin War, the Prime Evils and the angels of the High Heavens, compiled by the last Horadrim for his niece Leah. Text is credited to Flint Dille. It is presented as an artefact from inside the world, illustrated throughout, and it became the template every later Diablo lore tome follows.
The census records the hardcover at 9781608870639 and the paperback of 2016 at 9781608878024. One documentation quirk is worth knowing: an Insight press release printed the hardcover number in a hyphenated form ending in a digit that looks off, but the catalogued ISBN-13 that passes checksum is 9781608870639, and that is the number to check a copy against.
Book of Cain is volume one of what became the Horadric Vault set. It was followed by Book of Tyrael in 2013, Book of Adria in 2018, Book of Lorath in 2023 and Book of Prava in 2024, and the first four were gathered in the Horadric Vault Complete Collection box in 2023. Of the five, Cain remains the one most often bought alone, because Cain himself is the series' narrator figure across three games.
As a physical object it rewards the hardcover. The 2011 hardcover is the first edition form; the 2016 paperback is a reading and shelf filling copy with its own ISBN. Listings that show the paperback number against hardcover photos, or the reverse, are common enough that the ISBN check on this page is worth the ten seconds it takes.
No Japanese edition of Book of Cain exists. The census found no Japanese editions for any of the Diablo lore tomes.
