
Assassin's Creed is a nonlinear action-adventure video game in which players take control of Altaïr Ibn-La'Ahad, a 12th-century Levantine Assassin, during the events of the Third Crusade. His experiences are relived through the Animus by his 21st-century descendant, Desmond Miles. The Director's Cut Edition includes four memories exclusive to PC, such as the Rooftop Race Challenge, the Archer Stealth Assassination Challenge, the Merchant Stand Destruction, and the Informant Escort Challenge.
Desmond Miles, a bartender, is taken by Abstergo Industries to serve as a test subject for the "Animus," a machine that can access genetic memory. Abstergo plans to use the device to access the memories of Desmond’s ancestor, Altaïr Ibn-La'Ahad, a member of the Assassin Brotherhood in 1191, who lived during the Third Crusade in the Holy Land. At first, Desmond struggles with the device, but after a few days, he begins to experience Altaïr's past. The game then shifts primarily to Altaïr's perspective, with occasional returns to Desmond due to issues with the Animus or the Bleeding Effect. The story begins with Desmond entering Altaïr's memory, but he quickly encounters synchronization problems. Lucy Stillman and Warren Vidic can be heard arguing over Desmond's safety in the Animus. After several issues, Desmond exits the simulation, and Vidic explains the Animus' functions before starting a tutorial. Once the tutorial is complete, Desmond enters the nearest synchronizable memory of Altaïr. Lucy explains that Desmond must relive key events in Altaïr's life to improve synchronization, eventually reaching the final memory that contains the information Abstergo is after. Altaïr is first seen trying to retrieve one of the "Pieces of Eden," ancient artifacts, from Solomon's Temple with the help of Malik Al-Sayf and his brother Kadar. They are interrupted by Robert de Sablé, the Grand Master of the Knights Templar and the Assassins' enemy. During the attempt, Altaïr violates the three core principles of the Assassins' Creed in a failed attempt to kill Robert. In the chaos, Malik's brother is killed and Malik loses his arm, which is later removed. Returning to the Assassin stronghold in Masyaf, Altaïr apologizes, but Malik, having survived de Sablé and recovered the artifact, criticizes Altaïr for his pride. After fending off a Templar attack, Al Mualim, the leader of the Assassins, demotes Altaïr but gives him a second chance to prove himself. He is tasked with assassinating nine key figures in the Holy Land—Jerusalem, Acre, and Damascus—to bring peace between the Crusaders and Saracens. Each target is a real historical figure from the Third Crusade, including Majd Addin, Garnier de Naplouse, Jubair al Hakim, Abu'l Nuqoud, Sibrand, William of Montferrat, and Robert de Sablé. Altaïr completes each mission, uncovering how each target is linked to Robert and the Templars, and how they plan to end the Crusades by taking control of the Holy Land. As he eliminates the targets, he learns that Robert’s final scheme is to unite the Christian and Muslim forces against the Assassins. Altaïr defeats de Sablé before Richard the Lionheart, failing to convince the king to end the war, but stopping Robert’s plan. From de Sablé, he learns that Al Mualim was once a Templar who had used the Assassins to kill others who knew the artifact's power, so he could keep it for himself. Returning to Masyaf, Altaïr confronts his master, who reveals the truth: the Piece of Eden, which Altaïr had helped recover, creates illusions. Al Mualim dismisses religion and other supernatural events—like the Ten Plagues, the Red Sea parting, and the Greek gods in the Trojan War—as illusions caused by the artifact. He plans to use the Piece to control humanity and end all conflict. Altaïr sees through the deception and kills Al Mualim. When he retrieves the artifact, the Piece of Eden activates, displaying a holographic map of the world with other Pieces of Eden marked around the globe. After the memory is complete, Desmond learns that Abstergo is a modern front for the Templars, already searching for other artifacts at locations from Altaïr's memories. He also discovers that the modern-day Assassins tried to rescue him but failed. Desmond was to be killed by a high-ranking Templar, Alan Rikkin, but Lucy Stillman saves him. At one point, she tucks her ring finger into her palm, a nod to the Assassin tradition of removing the finger. Though still trapped in the Abstergo lab, Desmond experiences the Bleeding Effect, allowing him to use Altaïr’s Eagle Vision. This lets him see strange messages painted on the walls and floor of his cell. The messages reference various apocalyptic scenarios from different cultures, including multiple mentions of December 21, 2012—the day Abstergo plans to launch a satellite to "permanently end the war." It is implied that this will be done using the same method Al Mualim used on Masyaf, but on a global scale. The game ends with Desmond questioning the meaning of the messages and who could have drawn them.
| PC | April 8, 2008 |

| Audio | Subtitles | Interface | |
|---|---|---|---|
| English (US) | ✓ | ✓ | |
| Français | ✓ | ✓ | |
| Deutsch | ✓ | ✓ | |
| Italiano | ✓ | ✓ | |
| Русский | ✓ | ✓ | |
| Español (España) | ✓ | ✓ |