'The Hangover' star Bradley Cooper thinks sequels should follow similar formats to the original movie in order to be successful.
Bradley Cooper is pleased 'The Hangover Part II' follows the same formula as the first movie.
The actor is set to reprise his role as Phil Wenneck in the forthcoming sequel - which sees a group of friends head to Thailand for a bachelor party which gets out of hand - and he thinks it is more likely to be a hit because the plot is similar to that in the 2009 film, which saw the men trying to piece together the events of an evening celebrating the final single days of a pal in Las Vegas.
He said: "The sequel can't be, 'Let's make a movie that has a completely different story but it won't matter because people love seeing those guys together.'
"I don't believe that - when you look at sequels that don't work in comedy, it's when they abandon the formula. I was very happy that there was a structure - a ticking clock, a missing night."
Bradley enjoyed working on the movie sequel, and admits he hope sit lives up to expectations because he is such a fan of the first film.
He told GQ magazine: "I feel like, 'God, I hope it's good' just because I'm a fan of the first one and I want it to be worth it.