抗战期间，东北赌王于镇海（郑少秋 饰）为了帮助恩师夺回被上海流氓大亨冯敬尧（潘志文 饰）夺走的赌场百乐门，带着手下和恩师的儿子洛天佑来到了上海。于镇海向冯敬尧下了赌桌挑战贴，筹码就是百乐门，冯敬尧虽然心知来着不善，但为了面子还是答应出战。一时上海黑白两道大为紧张，人人都争相想看这场被称为世纪赌局的赌坛对决。同一时间，满腔热血的爱国青年许文强（陈锦鸿 饰）也来到了上海，想要在这里闯出自己的一片天地。出来上海的他偶然结识自小在这里长大的小贩丁力（林家栋 饰），两人结为兄弟，开始一起打天下。在祥贵和交际花方艳云的帮助下，许文强和丁力渐渐在黑道闯出名气，许文强更与于镇海结为莫逆，共同经营剧院。表面平静的上海滩内正酝酿着一场场你死我活的争斗。

Set in 1930s Shanghai, the story opens with legendary gambler Gon and his vow to recover his father's casino from Shanghai tycoon Fung In his quest, he becomes acquainted with Sou and uncovers her fiance's nefarious conspiracy. Sou gives her heart to Gon, but he can't forget his old love Gu. Meanwhile, up-and-coming gangster Hui Man Keung is quickly making his name in Shanghai. Crossing paths during chaotic times, Hui, Gon, and Ding Lik become brothers and business partners, but Fung recruits Hui and Ding to his side through backhanded methods. Though deeply in love with Fung's daughter Ching Ching, Hui can only turn away from love and friendship when Fung's true nature is revealed. Fung, however, is not about to just let Hui walk away.