Ubisoft's latest in the Assassin's Creed series sold 1 million copies within a week of its European release, according to the company's regional Chief of Sales & Marketing.
Geoffery Sardin also told games industry site MCV that he expects the series to pass 30 million sales by the end of the year.
Assassin's Creed: Brotherhood was released on November 19 in Europe for the PlayStation 3 and Xbox 360 consoles, and was the first in the series to feature an online multi-player mode in addition to a single-player story.
Each Assassin's Creed game takes place within a real historical setting, the 2007 debut during the 12th century's Third Crusade, and both the 2009 and 2010 follow-ups in Renaissance Italy.
They concern a struggle for power between the Knights Templar and Assassins, with each group seeking powerful artifacts. In each, players take on the identity of Assassins, clambering up walls and leaping from rooftop to rooftop in pursuit of their marks.
Other titles, such as inFamous, Prototype, Crackdown, The Saboteur and Just Cause 2 use similar go-anywhere mechanics, albeit against very different backdrops.Reuse content