Zac Efron gives a wickedly funny turn as the frat-boy foe of suburban couple Josh Rogen and Rose Byrne in this lewd, crude and often riotously funny comedy.

Flashing his abs and a wolfish grin, he’s the party-hearty president of a college fraternity that has moved next door to Rogen and Byrne’s new parents.

The thirtyish yuppie duo try to get on with their new neighbours, but the generation-gap friction eventually escalates into all-out war.

Rogen, Byrne and Efron throw themselves into the ensuing comic mayhem with gusto, while director Nicholas Stoller gives the pranks and japes a rollicking momentum.

Gags involving plaster-cast penises, obscene topiary and alcohol-laced breast milk won’t be to all tastes, but at its slapstick best the film is uproarious.