When Steve Buscemi read the first script for “Boardwalk Empire” more than a year ago, he knew he was looking at something totally different in his career. “I’d never had the chance to play anything like this before,” he said. “I knew I wanted to do it, and I was lucky to get the part.”

The industry has noticed, too. Buscemi, known for the quirky roles in independent films for most of his career, earned an Emmy nomination for Outstanding Lead Actor in a Drama Series this year for his portrayal of Atlantic City treasurer Enoch “Nucky” Thompson. He’s a man of duality — a kiss-the-babies politician by day and an illegal-alcohol kingpin during Prohibition by night.