The brothers of the Castellano Crime Family wage war against each other to gain control over their city after their father dies without naming an heir.

Alliances are built and tested as a band of heroes fight to return nobility and fairness to a justice system that has outlawed costumed vigilantism.

育碧今日（2010年11月3日，暂时没有imdb编号）早些公布了由Workshop制作的动画短片《刺客信条：权势(Assassin's Creed Ascendance)》的预告片，该作将于11月16日与《刺客信条：兄弟会》同步登陆XBLA和PSN，售价1.99美元或160微软点数。 《刺客信条：权势》背景时间设定在《刺客信条2》和《刺客信条：兄弟会》之间，Ceasare Borgia用武力统治了罗马甚至是整个意大利，通过血腥镇压、暴政等等使人民感到恐惧。Ezio Auditore将牢记Ceasare Borgia通过残酷的手段(投毒、暗杀)到达统治的目的。从此展开一系列的故事。