It is the third major installment in the Assassin's Creed series and the second chapter in the "Ezio Trilogy". The game is a direct sequel to Assassin's Creed II, with Ezio Auditore da Firenze and Desmond Miles returning as the main protagonists, and it takes place right after the conclusion of the previous game's story. It is the first game in the main series to feature a multiplayer mode. Assassin's Creed: Revelations is a sequel to the game, concluding Ezio's story as he travels to Constantinople.
The game introduces a new management system: the player can recruit new members by destroying any of fifteen "Borgia towers" around Rome where papal troops are stationed, then rescuing disgruntled citizens in their districts from harassing guards. The player, as Ezio, can then send them to assignments around Europe or call them for support during missions (if they are not already occupied). Tasking the novice Assassins makes them gain experience, and the player is able to customize their appearance, skills and weapon training to some degree by spending the skill points they have earned. Assassins can die on missions, from which they will not return. Ezio masters new gadgets, such as Leonardo da Vinci's parachute, which can be used when jumping from tall buildings, along with poison darts, a faster acting poison, a crossbow, and the ability to hold and throw heavier weapons like axes.
Ezio using the BAM system (Brotherhood Assist Move).
The combat system has been modified. Striking first and offensive actions are more deadly in Brotherhood than previous games where counter-attacks were the most efficient. Before, this made the player wait until the AI struck, which slowed down the pace of fighting. The AI in this game is thus more aggressive and enemies can attack simultaneously. To dispatch them, Ezio can use melee and ranged weapons at the same time, as well as introducing the hidden pistol in combat. After killing one enemy the player can start an execution streak to dispatch multiple enemies quickly. Ezio can throw heavy weapons (axes, spears, and swords) at his enemies. There are new enemy archetypes in addition to those seen in Assassin's Creed II such as horsemen, arquebusiers, papal guards and others.
Unlike previous installments, Desmond can leave the Animus at almost any time. This allows Desmond to explore the present-day town of Monteriggioni. The player is also offered virtual training, a mini-game where the player may test their free-running or combat skills.