While filming a big-budget war movie in Vietnam, a group of spoilt actors, including Ben Stiller, Robert Downey Jr and Jack Black, end up fighting drug lords for real.

Co-written and directed by Stiller, this is a hilarious, no-holds-barred send-up of Hollywood pomposity and folly.

Downey Jr’s method actor Kirk ‘I don’t break character till the DVD commentary’ Lazarus and Black’s drug-addled Jeff Portnoy are brilliant creations, as is Steve Coogan, in a brief role as their idiot British director who takes them deep into the jungle to complete the film ‘guerrilla style’.

But then they unwittingly stray into territory controlled by drug lords and have to fend for themselves against real bad guy carrying real weapons.

Tropic Thunder aims a blunderbuss at its targets, but it also delivers big laughs – especially when Tom Cruise delivers an inspired cameo appearance as a movie mogul. Nick Nolte, Jay Baruchel and Matthew McConaughey are also among the cast.

This film is showing at 12.20am on BBC1 Northern Ireland.