By the time of Assassin's Creed Unity, Abstergo distributes its Animus product via a video game console named Helix, tapping into an extensive, unaware player base to help them locate more Pieces of Eden and determine the fates of various Sages as part of the Phoenix Project, an attempt to recreate the genetic structure of the Isu. In early 2022, it was reported that a new Assassin's Creed game, titled or code-named Rift, was in development and expected to release in late 2022 or early 2023.

The pirated version of Assassin's Creed was one of the most popular titles for piracy during the first week of March 2008.

The player's health is described as the level of synchronization between Desmond and Altaïr's memories; should Altaïr suffer injury, it is represented as a deviation from the actual events of the memory rather than physical damage. Period three will launch with Assassin's Creed: Codename Red, using lessons from the second period of development to make engrossing single-player games similar to the original titles but with features to allow players to share achievements and content with others, all to be backed by the Infinity hub system. To encourage the player to explore, they included the various towers that help to reveal parts of the map. Basim helps Layla stop the disaster before escaping back to reality, where he uses the Staff to rejuvenate himself and meets the other modern-day Assassins. After Altaïr mortally wounds him, Robert identifies Al Mualim as the final conspirator, revealing that the latter has betrayed both the Assassins and Templars to acquire the Apple.

Vidic instructs Desmond to relive the early years of Altaïr Ibn-La'Ahad ( Philip Shahbaz), a senior member of the Assassin Brotherhood during the Third Crusade. The group continues to find the vaults across the globe via Desmond's memories, and Desmond ultimately activates them in time to block the solar flare, at the cost of his own life.

Desmond continues exploring the memories of Ezio, who, a few years after the events of Brotherhood, travels to Constantinople to find five keys needed to open a library built by Altaïr, which is said to contain the power to end the Assassin–Templar conflict. On the decision, Guillemot said that "Ubisoft started to question the annualized franchise with the release of Assassin's Creed Unity, and the fact that Assassin's Creed Syndicate had "a slower launch than expected". Initial work on the game was to expand out various systems from Prince of Persia to the open world concept with a team of 20 at Ubisoft Montreal. A Microsoft Windows version titled Assassin's Creed: Director's Cut Edition containing additional content was released in April 2008.

Versions of these societies have existed for centuries, with the Assassins seeking to stop the Templars from gaining control of Pieces of Eden, artifacts that can override free will to control people. Following the events of Brotherhood, where he was possessed by Juno and forced to kill Lucy (who, unbeknownst to him, was a Templar double agent), Desmond has fallen into a coma and was put back into the Animus to save his mind.The game began work under the title Prince of Persia: Assassin, [13] or Prince of Persia: Assassins, [12] inspired by Hassan-i Sabbah's life and making heavy use of Vladimir Bartol's novel Alamut.