Upon arrival at the luxurious Caesars Palace hotel, several hours of heavy drinking ensue, and, in the morning Phil, Stu and Alan wake with pounding headaches and no memory of the night before.

A trashed hotel suite and the presence of a baby in a closet are the first signs that something is dreadfully awry; the absence of the groom-to-be comes a close second.

As the three men hazily retrace their alcohol-fuelled steps, encountering a stripper called Jade (Graham) and the mysterious Mr Chow (Jeong), they begin to understand quite how much trouble they and Doug are in.

Directed by Todd Phillips, whose previous male-bonding exercises include Road Trip and Old School, The Hangover is a mish-mash of ideas which never gel.

If there is a method to screenwriters Lucas and Moore’s madness, it remains hidden until the end credits when snapshots reveal what happened in Vegas in lurid detail.

The three leads sweat blood and tears, literally, to wring out every last chortle from the set-ups.

Galifianakis snaffles most of the giggles with his idiot savant’s random outbursts: "Tigers love pepper, they hate cinnamon."

Stu’s romantic sub-plot is undernourished, lessening the impact of the final showdown with his adulterous, harridan girlfriend (Harris).

Sometimes love means saying: "I don’t."

THE HANGOVER (Cert. 15, 99 mins) 
Stars:  Justin Bartha, Bradley Cooper, Ed Helms, Zach Galifianakis, Heather Graham, Ken Jeong, Jeffrey Tambor, Rachael Harris, Sasha Barrese
Directed by Todd Phillips.