"At the moment, I think it's the fear that keeps us together. Whereas, when we were in London doing it for a long time, it was very hard to keep it together very often. [Star] James Corden very much likes to make us laugh on stage, if he can," the 30-year-old actress told United Press International in a recent phone interview. "I think, at the moment, we're still kind of thrilled and excited and honored to be on Broadway, so everyone's being a bit better-behaved."
The West End transfer, which originated at England's National Theatre last June, is an adaptation of the 1743 Commedia del Arte comedy "Servant of Two Masters" by Venetian playwright Carlo Goldoni. It opened last month on Broadway to rave reviews and has been nominated for seven Tony Awards, including Best Play.
Set in 1963 Brighton, England, the comedy stars Corden as the excitable, eager-to-please errand-boy torn between two employers -- a wealthy, dim-witted snob [played by Oliver Chris] and his fiancee, a woman posing as her deceased mobster brother [played by Rooper]. Neither boss knows the other is in town or has hired the hapless assistant. The many mishaps and misunderstandings that follow are played to hilarious effect.
So, what is it like playing the role of Rachel, a woman posing as her deceased gangster sibling Roscoe to cover up the fact her fiance killed him?
"The hardest thing was changing and using my voice a lot," Rooper noted. "But apart from that, it's really fun and I have a ball doing it."
Asked if she thought, "I am one cool dude," when she first looked in the mirror and saw herself decked out to play Roscoe, Rooper said with a laugh, "I wanted all the women and all the men to fall in love with me."
She went on to recall how it initially was difficult to imagine herself as a male criminal during the rehearsal period for the show because she was wearing her everyday clothing and had long hair.
"As soon as I got the costume on, everything felt complete. Now, I find it very weird to look at my face without sideburns," said the actress, who also wears a short black wig for the play.
For Rooper, one of the most satisfying elements of the show is the audience's raucous response during each performance.
"That's been the most phenomenal thing about the project," she said. "It really feels like people come and have an amazing time. People need to laugh and it's such a good medicine and it's so lovely for us that we're able to create that place where they can come for a few hours and watch a silly show and just laugh their heads off. ... There are a few places on the stage where I can peek out at the audience and I still love seeing the people and watching as they get tears in their eyes [from laughing so hard]."
Rooper confessed she was surprised her 2008 "Pride & Prejudice"-themed miniseries "Lost in Austen" and angels-demons drama "Hex," which aired from 2004 to 2006, have such tremendous followings outside the United Kingdom.
"I think more people come up to the stage door here than in London," she said. "There's a bit of a cult following for the show ['Hex'] and you sort of forget about that. And, suddenly, I'm here and people know what I've done. It's really nice."