Which 2010 Assassin's Creed game introduced the multiplayer mode and continued Ezio's story in Rome?

Assassin's Creed: Brotherhood introduced the series' first major multiplayer mode and continued Ezio Auditore's story in Rome.

Released in 2010, Brotherhood follows Ezio after the events of Assassin's Creed II. Much of the campaign is set in Rome, where Ezio works to weaken the Borgia family's control and rebuild the Assassin Brotherhood. The game adds a system for recruiting and training new Assassins, who can assist him during missions.

Its competitive multiplayer mode placed players in the roles of Templars hunting one another through crowded environments. The mode emphasized blending, observation, and carefully timed assassinations rather than conventional team combat alone.

Brotherhood is sometimes mistaken for Revelations because both continue Ezio's life. Revelations was released in 2011 and moves the story largely to Constantinople, while Brotherhood remains especially associated with Rome and the expansion of Ezio's organization.