Assassin's Creed: Revelations is an action-adventure, stealth game set in an open world environment and played from a third-person perspective. The game features three distinct protagonists: Ezio Auditore, Altaïr Ibn-LaʼAhad, and Desmond Miles. When playing as Ezio or Altaïr, the game retains the series' standard gameplay formula, consisting of a mixture of combat, stealth, and exploration. While the base gameplay remains virtually unchanged from the previous title, Assassin's Creed: Brotherhood, Revelations does add several new features; most notably, the "Hookblade," which acts as a replacement for Ezio's traditional dual Hidden Blade (which is broken at the beginning of the game). The Hookblade is intended to facilitate traversal and compensate for Ezio's old age, allowing him to climb buildings much faster and reach further ledges. It can also be used to jump over large gaps and access ziplines across the environment. Reportedly, the Hookblade speeds up navigation by around 30 percent.[1] The Hookblade also has applications in combat, allowing for new moves such as grabbing and yanking enemies for a combo attack.
The main protagonist, Ezio, can use the hookblade to access ziplines across the environments and perform air assassinations on enemies. The hookblade is one of the new features introduced in Revelations.
Another new aspect of the game is bomb crafting. Introduced early on in the story, this mechanic allows Ezio to experiment with different shells and ingredients to create bombs with various effects, such as smoke to distract guards or lethal explosions that can take out large groups of enemies. There are around 15 different bomb variations in the game, although only three can be equipped at any given time.[2]
Revelations is primarily set in the city of Constantinople during the rise of the Ottoman Empire. It is similar in size to Rome from Brotherhood, and just like it, it can be renovated by purchasing different stores, such as armories, book shops, and apothecaries. Doing so not only grants Ezio access to that store's services, but also increases the passive income generated by the city, which is deposited in the bank and must be collected regularly. The player can also renovate several of Constantinople's landmarks, like the Galata Tower, Hagia Sophia, and the Topkapı Palace, to increase their income. Other locations visited during the story include Masyaf and Cappadocia.[3]
Similarly to Brotherhood's "Borgia tower" system, players can gradually take control of Constantinople from the Templars by destroying their towers in each of the city's districts and killing the Templar captain stationed there. However, this feature has been expanded, as now the Templars will attempt to reclaim their tower if Ezio's notoriety in that district becomes too high and the player has not yet taken over the other Templar dens. When this occurs, the player will have to defend the tower in a "Den Defense" minigame, where they control a group of Assassins from the rooftops and must fight off multiple waves of Templar soldiers and siege equipment.
Another returning feature from Brotherhood is the ability to recruit Assassin initiates and call them for support during missions or send them on assignments to other cities around the Mediterranean Sea, which are controlled by the Templars.[4] By completing contracts, the initiates gain experience and level up, granting them access to better equipment, and also reduce the Templar influence in a particular region. When Templar control over a city is weakened enough, the Assassins can launch an attack to try and take it over. To prevent the Templars from reconquering a city, Ezio can assign up to five Assassins to be permanently stationed there. An Assassin recruit who has reached the highest possible rank can be assigned to serve as the "Den Master" for any of the Assassin-controlled towers in Constantinople. This allows them to level up five additional ranks and also unlocks a unique mission for each district, in which Ezio and the Assassin hunt down a dangerous Templar in that area of the city.
Other side activities include Piri Reis Missions, which teach the player about the different types of bombs that can be crafted; Guild Challenges for any of the three ally factions in the game (Thieves, Mercenaries, and the Romani); and finding rare books for Ezio's love interest, Sofia Sartor. In-game collectibles include treasure chests, Animus data fragments, and Ishak Pasha's Memoir Pages, the last of which unlock a secret mission akin to the Assassin Tombs from Assassin's Creed II and Lairs of Romulus from Brotherhood, in which Ezio must explore the inside of Hagia Sophia to retrieve Pasha's armor set.
Outside of the Ezio sequences, the game also features six Altaïr memories, which are unlocked after Ezio retrieves each "key" for the Masyaf library. In these sequences, Ezio is reliving key memories from Altaïr's life in Masyaf, during which the player controls the latter. Besides Ezio and Altaïr, the player can also play as Desmond in the modern day, whose mind is stuck in the computerized core of the Animus, known as "Animus Island." The island acts as a mini-hub, from where Desmond can access five memory sequences known as "Desmond's Journey," as long as the player has collected enough data fragments or has The Lost Archive DLC installed. These sequences play differently from anything that has come before in the series, as they involve first-person platforming and puzzles, while the story is provided in the form of narration by Desmond, who recounts his life prior to the events of the first Assassin's Creed game. 
The console versions of the game support the stereoscopic 3D mode for both 3D-HD and 2D-HD television screens. All Revelations gameplay videos and cinematics have S3D support.