HBO’s Prohibition-era drama Boardwalk Empire opened its second season with 2.9 million viewers. That was down 40% from Boardwalk Empire‘s series debut last September, when it posted HBO’s largest series premiere audience in six years. There was a mitigating factor: the series premiere ran on the Sunday before the broadcast premiere week, while the Season 2 opener aired on Premiere Week Sunday, facing stiffer competition. (Boardwalk Empire‘s first season finale drew 3.3 million in its original airing). Including two additional plays at 10 PM and 11 PM, Boardwalk Empire‘s Season 2 premiere averaged 4.5 million viewers.