Initially intended as an art book, the project gathered so much material and Ubiworkshop eventually decided to expand it into an encyclopedia.

Artists like Craig Mullins, Tavis Coburn, 123Klan, Gabz, James NG, David Alvarez and many others were given free reign to draw an Assassin from the period and style of their choice, of which the artworks were included in the Encyclopedia. There was also a “cartes blanches” section that featured artwork by other professional artists and fans of the series.

The first book was released in three editions. Black Edition, White Edition and an E3 Collector’s Edition.

The Black Edition was released with the Animus Edition of Assassin’s Creed Revelations. The White Edition was released through UbiWorkshop and with the Ultimate Edition of Assassin’s Creed: Revelations. The E3 Collector’s Edition was given away to press members who attended E3 2012 in a cloth bag with Assassin’s Creed III logo on it. The book itself had a new silver cover.

After the success of the first book and the release of new games, adding up more artworks in addition to the story material, characters, locations and new information, a Second Edition (2.0) was released in October 2012 to coincide with the release of Assassin’s Creed III. The Second Edition features 120 new pages of content that include information on Assassin’s Creed III, Assassin’s Creed III: Liberationand Assassin’s Creed: The Chain along with new cartes blanches.

In October 2013, the Third Edition (3.0) was released to coincide with the release of Assassin’s Creed IV: Black Flag. The Third Edition contains over 390 pages of content revised and updated with information from Assassin’s Creed IV: Black Flag and Assassin’s Creed: Brahman. 

The Assassin’s Creed Encyclopedia is divided into four sections: factions, story, characters and places.