The slogan "What Happens in Vegas... Stays In Vegas" has been very lucrative for some copywriter and relatively fruitful for lazy scribes yearning for easy ledes to start stories about Sin City (guilty as charged), but it's an entirely ineffective strategy when you're seated with a group of movie stars just dying to promote a movie by telling tales of what happened to them in Las Vegas.

"The Hangover," new in theaters on Friday (June 5), tells the eternal story of four men on a bachelor party in Las Vegas, a story that includes roofies, a baby, a tiger, a stripper, an Asian mobster and Mike Tyson. But mostly, it's the story of Las Vegas, where stars Bradley Cooper, Ed Helms, Justin Bartha and Zach Galifianakis spent survived several weeks of production.

"It served the movie very well, because you sort of can't fake that feeling of what it's like to be here for a month and a half in a casino," Cooper tells reporters at the recent "Hangover" junket. "So it really fueled everything. Because there's a grittiness. Vegas is sort of the fifth character of the movie. And luckily, we shot the Vegas portion first, and then the LA portion second. So we sort of brought what this town does to you to LA. But yeah, you know, you feel like you're in this sort of crazy other world when you're here for so long."

Bartha adds, "Whenever I came to Vegas for two night and, like most people, you're always like 'Well, it's one night too many.' So if you're here for a month-and-a-half, I think that in Vegas time, I think that's a year-and-a-half. A 12-hour day feels like a two-day day."

Under the direction of Todd "Old School" Phillips, the cast was based out of Caesar's Palace casino, which plays itself in the film and also hosted the "Hangover" junket, which found journalists and stars sitting in an upper-level suite staring out two-story windows onto the Strip below. Just because The Strip is the popular image of Las Vegas, though, doesn't mean that that's where most of "The Hangover" takes place. In addition to the usual haunts, Phillips and his team showed the other side of Las Vegas.

"I've always thought of Vegas as a sort of like dark wonderland. Like it's sort of like a sort of f***ed up amusement park," Helms says. "And then when you spend five, six weeks here--and we were shooting all over the city, like places where tourists never go--this city actually becomes normal. Like you start to see the things that really are normal about the city, like little league baseball teams, and a library. And like all these things that you just never associate with Vegas. Like, "Wow, people live here. And function here. Pretty normally." 

Most normal Las Vegas residents don't have to deal with many of the things that were foisted upon the "Hangover" cast, things like sharing scenes with a tiger.

"The trainers give you this whole hour-long speech about what to do and what not to do when a tiger's around and never be this close to the tiger, never pet the tiger and then our first take, the trainer's by craft service and the tiger's just walking around," Bartha recalls.

Or obstacles like an excitable director eager to taser his cast for one key comic set piece.

"Yeah, he did want us to be shocked," Cooper chuckles. "Luckily Warner Bros said that was illegal. So we didn’t do that."

"He’s so funny, Todd, because he’s like, 'We really want to taser you because I just want you to have something to react to,'" Helms recalls. "I was like, 'No, you can't taser me. I'm an actor. I can act like I'm being tased.' He's so cajoling. He's like, 'You know we dialed it down from 50,000 to 30,000 volts so it won’t be as bad.'"

But as central as Las Vegas is to the "Hangover" story, Bartha argues that a follow-up movie -- and the sequel is already in development -- wouldn't necessarily have to take place in the Nevada desert.

"I think it could absolutely be probably just as funny, maybe if not funnier, anywhere," Bartha insists. "I think this is a great jumping off point, just because Vegas is such a den of sin and it plays into the accelerated outrageousness that happens in the movie, but I think that because of Zach and Ed and Bradley and Ken Jeong and Heather Graham and Mike Epps and everyone involved, these are funny people and they work well together. I know Zach and I know Ed and I know Bradley. They make me laugh every day, even when we're not in Vegas, so I think that can translate anywhere."

 

"The Hangover" is now in theaters.