Downtown New York got a taste of casino culture Wednesday night when the Cinema Society and Calvin Klein Jeans hosted a special screening of “21.” The film has Kate Bosworth and Jim Sturgess as MIT students who use their smarts to make major dough at the Vegas blackjack tables.

As curious onlookers crammed the streets outside the IFC Center, Bosworth (who also is featured in the fashion house’s Spring campaign) admitted to having mastered a pretty good poker face.

“I think you need one to be in this industry,” she joked. “But in my personal life I wear my heart on my sleeve.”

A few feet away, her co-star Sturgess was looking much more like a dapper card shark than a scruffy college student. “They made me look proper,” he grinned of his Calvin Klein threads.

There was blackjack at the afterparty at the Mercer Kitchen, but Sturgess avoided the tables, holing up on a banquette with friends as the likes of Mary-Kate Olsen, Clive Owen, Catalina Sandino Moreno, Helena Christensen and Elle Macpherson made the rounds fueled by Champagne, mini burgers and fries.

The B-52’s Fred Schneider was less restrained as he headed straight for the tables.

“I’m off to Vegas next week so I guess I better start practicing,” he said.