战乱年代，群雄并起。割据一方的沛国安于现状，一任国主沛良（郑恺 饰）慨歌太平。要冲之地境州早年为强邻炎国借去，而今据而不还。沛国都督子虞（邓超 饰）前往讨伐，却中了对方大将杨苍（胡军 饰）的拖刀，重伤不愈。心有不甘的子虞暗中派出替身境州（邓超 饰）假扮自己，总理军政，内则使令夫人小艾（孙俪 饰）襄助。真假子虞切磋战法，寻求破解杨苍刀法的绝技。而另一方面，沛良恼怒子虞私自约战杨苍，不惜将妹妹青萍（关晓彤 饰）嫁于杨苍之子为妾媾和。淫雨霏霏，连日不开。境州上空，杀戮与机谋纠缠撕裂…… 　　本片根据朱苏进的剧本《三国•荆州》改编。Set during China's Three Kingdom's era (AD 220-280). The story of a great king and his people, who will be expelled from their homeland and will aspire to claim it. The king, violent and ambitious, of mysterious methods and motives; his general, a visionary who yearns to win the final battle but needs to prepare his plans in secret; the women of the palace, who struggle to find redemption in a world where they have no place; and a commoner called "Lord of all the world", will be the characters around who turn the inexorable forces of this story.