Angelenos Doug Billings and Tracy Garner are about to get married. Two days before the wedding, the four men in the wedding party - Doug, Doug's two best buddies Phil Wenneck and Stu Price, and Tracy's brother Alan Garner - hop into Tracy's father's beloved Mercedes convertible for a 24-hour stag party to Las Vegas. Phil, a married high school teacher, has the same maturity level as his students when he's with his pals. Stu, a dentist, is worried about everything, especially what his controlling girlfriend Melissa thinks. Because she disapproves of traditional male bonding rituals, Stu has to lie to her about the stag, he telling her that they are going on a wine tasting tour in the Napa Valley. Regardless, he intends on eventually marrying her, against the advice and wishes of his friends. And Alan seems to be unaware of what are considered the social graces of the western world. The morning after their arrival in Las Vegas, they awaken in their hotel suite each with the worst hangover. None remembers what happened in the past twelve or so hours. The suite is in shambles. And certain things are in the suite that shouldn't be, and certain things that should be in the suite are missing. Probably the most important in the latter category is Doug. As Phil, Stu and Alan try to find Doug using only what little pieces of information they have at hand, they go on a journey of discovery of how certain things got into the suite and what happened to the missing items. However they are on a race for time as if they can't find Doug in the next few hours, they are going to have to explain to Tracy why they are not yet back in Los Angeles. And even worse, they may not find Doug at all before the wedding. Two days before his wedding with the wealthy Tracy Garner, Doug Billings travels to his bachelor party in Las Vegas with his best friends, the school teacher Phil Wenneck and the dentist Stu Price, and Tracy's unconventional brother Alan Garner. Tracy's father lends his convertible Mercedez Benz that is his pride and joy to Doug with many recommendations. The quartet rents the best suite in the Caesar's Palace and they go to the roof to celebrate. Alan proposes a toast to Doug and they drink his booze. On the next morning, Phil, Stu and Alan have a hangover and they do not recall what they did last night; the room is upside down; Doug is missing; there is a baby in the wardrobe; a tiger in the bedroom; a chicken in the room; Stu has a missing tooth; and Doug is missing. The trio tries to track down last night to find what happened and sooner they discover that Stu married the stripper Jade (heather Graham) and Alan has spiked their booze with "Good Morning, Cinderella" in the beginning of their crazy night.
Just two days before his marriage with Tracy Garner, Doug Billings, in the company of two friends: Phil Wenneck and Stu Price; and Tracy's eccentric brother, Alan, head out to party in Vegas. Driving his father's Mercedez, they rent a pricey villa at Caesar's and head for the rooftop to have a good time. Three of them later wake up with a hangover, unable to re-collect what exactly happened. With the villa in a wreck, turned upside down, they find that they have a baby in the closet, a grown tiger in the bathroom, Stu has a missing tooth and a hooker for a bride, and Doug is missing. Hilarious chaos results as the trio head out to re-trace their steps, find out that occurred in order to try and locate Doug, and bring him home in one piece before the wedding.
