Synchronization

"We found similar reactions among patients who undergo hypnosis to relive traumatic events. They can't jump directly into the specific memory. They need to be eased in. Even then, there can be problems."

- Lucy Stillman to Desmond Miles, regarding the difficulties of synchronization.

Synchronization referred to the Animus' visual representation and measurement of its user's adherence to the memories of their ancestor. Following genetic memories exactly as they had happened would result in full synchronization, and consequent access to certain repressed ones.

Inversely, a loss of synchronization resulted in the instability of the memory, which would eventually culminate in expulsion from it entirely. If such a desynchronization occurred, the simulation would restart from an earlier point.

Maintaining synchronization
Synchronization was visualized by a bar on the top left corner of the Heads up display, and had a capacity of up to 20 bars for the Animus 1.28, and up to 25 bars for the Animus 2.0.

Once synchronization reached critically low levels, the Animus' screen would begin to flash blue and red, to warn the user that the current memory was growing unstable. If all synchronization was lost, the meter would disappear; with one more desynchronizing action triggering a complete restart of the memory.

The ancestor's mental state at the time of the memory heavily affected the user's reliving of the memory in the Animus. As such, Desmond Miles' very first use of the Animus caused an almost instantaneous loss of synchronization, as his subconscious could not yet handle the stress and trauma of the memory he was attempting to relive.

Since Desmond relived the memories of two of his Assassin ancestors, Altaïr Ibn-La'Ahad and Ezio Auditore da Firenze, his synchronization level was closely tied to how well he followed the Creed. Additionally, falling from heights, being injured in battle, or entering cordened off areas could resulted in a loss of synchronization, indicating that this had not happened to the ancestor at the time.

Similarly, being discovered in the process of an assassination would often result in an immediate loss of synchronization, as it did not happen to the ancestor. Accompanying this, certain events, despite seeming advantageous at the time, would cause desynchronization should it be inaccurate to the ancestor's actions.

Some additional memories did not affect synchronization, whether or not they were completed. These indicated that the ancestor had performed these actions, but they were not completely essential to the primary objective that the Animus subject required to complete. Such examples included collecting flags, and opening treasure chests.

In the Animus 1.28, synchronization lost would recover over time. However, in the Animus 2.0, the synchronization meter was treated as more of an indication of health, with the user needing to use medicine or visit a doctor in order to restore it.

Animus 1.28
For the Abstergo Industries Animus, synchronization was divided into base and additional synchronization. Base synchronization was tied to the main memory, while additional synchronization came from side memories.

For the memories of Altaïr, the base level of synchronization available increased along with his rank in the Assassin Order. Maximum synchronization in the memories of him as a Novice was four, but increased by one slot at every rank, until finally reaching thirteen at the rank of Master Assassin. This could suggest that the synchronization level was tied to the ancestor's skill level or capabilities at the time.

In turn, additional synchronization could be earned through completion of additional memories, such as saving citizens and climbing up to View Points. Completing fifteen of these would trigger the Animus to announce "DNA Synchronization Augmented" on its display, and it would increase the synchronization meter by one. Up to seven such additional bars could be obtained this way.

Animus 2.0
Synchronization in Rebecca Crane's Animus was seen as more of a status, and was indicated through percentage, rather than with a meter. Meanwhile, an additional health meter replaced the Animus 1.28's synchronization meter in function, and was composed of multiple square indicators.

Synchronization could be increased by completing side memories, recovering objects (such as Codex pages, feathers or statuettes), and through unlocking the Armor of Altaïr.

The health meter, in turn, was increased by equipping armor and deciphering Codex pages. Maximum health could be achieved while wearing Altaïr's armor, or a full Missaglias set, and by having all 30 Codex pages deciphered.

Unlike in the Animus 1.28, damage did not always completely deplete one square of the meter. Depending on the power of the attack received, or by the height of the fall, a square could only partially disappear, and would be recovered quickly after a few seconds. A completely empty square, however, would need to be healed or have armor repaired.

Animus 2.01
After her team had traveled to Monteriggioni, Rebecca added an additional feature to the Animus 2.0, allowing Desmond to aim for full memory synchronization in certain memories. To achieve this, Desmond was required to relive the memory almost exactly as his ancestor had.

The most common conditions for full synchronization were either time-related, weapon-specific, or required him to remain undetected. Failing to complete the optional condition, despite finishing the memory, resulted in a 50% completion message.

Completing any of the first seven main memory sequences with 100% synchronization would unlock a cheat that could be used when replaying memories.

Additionally, as Desmond increased his synchronization with Ezio, he began to unlock a number of his repressed memories. These were obtained after every 15% increase in total synchronization, until the fifth and final memory was unlocked at 75% synchronization.

Animus 2.03
After the events inside the Colosseum Vault, Desmond had fallen into a coma, and the Animus was used to monitor his state and keep him alive. Rebecca had shut down most of the systems to free up the memory, and created separate partitions for Desmond's consciousness to prevent its fragmentation.

On the Animus Island, Desmond spoke with Subject 16, who told him that the only way out of his catanotic state was to use the Synch Nexus, and relive the unfinished memories of his ancestors, until they had nothing left to show him. While these memories were not recorded by Desmond's fellow Assassins outside the Animus, as the monitoring system was disabled, the 100% synchronization conditions remained available for these memories.

Achievements
Four separate achievements involved the synchronization meter, and could be unlocked in Assassin's Creed, Assassin's Creed: Brotherhood, and Assassin's Creed: Revelations.