The series's eponymous first title was released in 2007, and it has featured twelve main games in total, the most recent being 2020's Valhalla. The series took inspiration from the novel Alamut by the Slovenian writer Vladimir Bartol, based on the historical Hashashin sect of the medieval Middle East, while building upon concepts from the Prince of Persia series.

In the majority of the games, players control a historical Assassin, while also playing as an Assassin Initiate or someone caught in the Assassin-Templar conflict in the present-day framing story. The series features historical fiction, science fiction and fictional characters intertwined with real-world historical events and figures. Created by Patrice Désilets, Jade Raymond, and Corey May, the Assassin's Creed series depicts a fictional millennia-old struggle between the Assassins, who fight for peace and free will, and the Templars, who desire peace through order and control. Assassin's Creed is an open-world action-adventure stealth video game franchise published by Ubisoft and developed mainly by its studio Ubisoft Montreal using the game engine Anvil and its more advanced derivatives.