Director: Todd Phillips
Stars: Zach Galifianakis, Bradley Cooper, Ed Helms
Plot: Three buddies wake up from a bachelor party in Las Vegas, with no memory of the previous night and the bachelor missing. They make their way around the city in order to find their friend before his wedding.
When the cop car pulls up in front of Caesar's Palace, two real employees are actually having an argument in the background about the filming of the movie.
No effects or prosthetics were created for Stu's missing tooth. Actor Ed Helms never had an adult incisor grow, and his fake incisor was taken out for the parts of filming where Stu's tooth is missing.
An actual taser was originally going to be used in the taser scene, but lawyers from Warner Bros. demanded that the crew use a prop.
Ironically, Bradley Cooper is a teetotaler in real life. He quit drinking at age 29.
Lindsay Lohan was offered the part of the stripper, Jade, but turned it down. She did not like the script and thought the movie would bomb. Heather Graham was given the role instead. Lohan later admitted to regretting the decision.
Mike Tyson revealed that he appeared in the film to fund his drug habit and that he was high on cocaine when he filmed his scenes. Tyson later said that working on the film convinced him to change his lifestyle.
The plot was inspired by a real event that happened to Tripp Vinson, a producer and friend of executive producer Chris Bender. Vinson had gone missing from his own Las Vegas bachelor party, blacking out and waking up "in a strip club being threatened with a very, very large bill [he] was supposed to pay".
During the scene where Phil, Stu, and Alan meet Chow in the desert, you can see their car pulling up in the reflection of Chow's sunglasses. This is a tribute to the scene in Casino (1995) where Nicky Santoro (Joe Pesci) meets Sam Rothstein (Robert De Niro) in the desert and you see the reflection of Santoro's car in Rothstein's sunglasses.
In the scene when they are walking to Jade's apartment, Alan refers to a show with Ted Danson, Magnum, P.I. (1980) and that Jewish guy. This refers 3 Men and a Baby (1987).
Ken Jeong improvised the nudity in the scene where he jumps out naked from the trunk. Originally his character was meant to have clothes on, but Ken suggested that his character be naked instead. Later, director Todd Phillips gave Ken a nudity waiver slip to sign in case Ken changed his mind on the nude scene.
According to Bradley Cooper, while giving a speech at a Toronto screening: "the people in Las Vegas never even noticed [a] movie was being filmed." He said that he had tiger scratches on his neck, all bloodied, and Justin Bartha was beet red, and nobody noticed, or even stopped to double-take.
In the DVD Commentary, Todd Phillips states that a possible explanation for the chicken in the room is that the guys intended to feed it to the Tiger.
The escalator scene in the casino is a tribute to Rain Man (1988). Alan and Phil have to win $80,000 in order to pay back Mr Chow. This is also the amount needed to win by Raymond and Charlie in Rain Man (1988).
Director Todd Phillips has a cameo as the guy making out with a woman in an elevator at the hotel.
Lucinda Jenney is at the casino, playing the same character she played in Rain Man (1988).