Scott Moore and Jon Lucas, co-writers of the first chapter of The Hangover trilogy, make their directorial debut with a raucous and gleefully foul-mouthed comedy that attempts to replicate the boozy shenanigans of their earlier script.

21 & Over harnesses the reckless abandon of three high school friends on the night that the youngest member of the trio comes of age and can legally buy and consume alcohol.

To celebrate, the pals embark on an ill-fated bender that includes a close encounter with a rampaging bull, a near-death experience with a swimming pool cover and naked humiliation at the hands of a sorority of enraged Latinas.

Like The Hangover, the film bolts together set pieces into a fractured and debauched narrative.

We first meet gung-ho Miller (Miles Teller) and strait-laced Casey (Skylar Astin) walking across a campus in their birthday suits, with red raw buttocks and a sock apiece to spare their blushes.

"None of that ever happened," they concur.

One day earlier... Miller and Casey arrive at the house of their pal Jeff Chang (Justin Chon), who is turning 21.

Birthday celebrations are put on hold because Jeff has an interview for medical school the next morning organised by his controlling father.

"I had to call in a lot of favours to get this interview," Dr Chang (Francois Chau) warns his son. "Be rested, be sharp - do not embarrass me."

After much persuading, Jeff agrees to accompany Miller and Casey out on the town for a couple of drinks before an early night.

Umpteen beers and shots later, the birthday boy is paralytic and Casey is smitten with a girl called Nicole (Sarah Wright), who is attracted to spontaneous, unpredictable men.

Sparks of mutual attraction are doused, temporarily at least, so that Casey and Miller can carry their buddy home to his bed.

"Jeff Chang's dad is going to honour kill him if we don't get him home for that interview!" Casey reminds Miller.

Unfortunately, neither lad knows Jeff's address so they embark on a madcap misadventure in search of inspiration, crossing paths with Nicole's oafish jock boyfriend Randy (Jonathan Keltz), who clearly doesn't deserve her.

21 & Over is considerably sweeter than The Hangover.

There's a pleasing contrast between Teller's leader of the pack, who has a stirring speech to justify heavy-drinking, and Astin's sensitive soul, who risks losing the girl if he doesn't act impulsively for the first time in his life.

Moore and Lucas's script treats the characters with affection and is peppered with belly laughs.

They also embrace bad-taste toilet humour, which hits a low with some DIY circumcision courtesy of a stuffed bear glued to Jeff Chang's nether regions.

The birthday boy screams in anguish and men in the audience share his exquisite pain by wincing and crossing legs in unison.

Rating: **