'YOU LIE A lot," medical school dropout Victor (Sam Rockwell) is told midway through Choke. That comes when, asked about a missing piece of his ear, and he claims he was clawed by a lynx.

Victor's mother, Ida (Anjelica Huston), brought up Victor to believe that his father was a Norwegian travelling salesman with Tourette's syndrome. Later he's told he was cloned from the foreskin tissue of a religious relic.

Ida is so delusional that she doesn't recognise Victor anymore, and she mistakes him for different lawyers she has known. He has to play along with this when he visits her in a mental institution.

The role-playing continues in Victor's job as an 18th-century Irish servant at a historical theme park. The other re-enactors frown upon the feckless attitude of Victor and his towering best friend, Danny (Brad William Henke).

Then there is the scam that gives the movie its title. Victor goes in a restaurant and engages in a routine whereby he seems to be choking to death while seeking out the wealthiest looking patron to apply the Heimlich manoeuvre. Even while Victor is taking a 12-step programme to deal with his sex addiction, he pretends to be taking it seriously but uses the meetings to pick up participants. "I have sex with strangers because I can't do it with people I like," he explains.

Trying to distinguish between fact and fiction is the most bemusing aspect of watching Choke, which frequently confounds assumptions in the revelations it offers. That's appropriate for a film in which the protagonist's insecurity is rooted in his confusion about his own identity.

What we learn about his past gradually and unexpectedly renders Victor more sympathetic than he seemed.

Most of the credit for that achievement rests with the intriguingly complex central performance from Rockwell, one of US cinema's most adventurous actors. This edgy dark comedy is based on the novel by Chuck Palahniuk, whose Fight Clubwas adapted for a far superior movie made with greater depth and ambition.

The Chokescreenplay is by first-time director Clark Gregg, who has an entertaining cameo as the theme park manager who approaches his role-playing with the dedication of a Method actor.

***

Directed by Clark Gregg. Starring Sam Rockwell, Anjelica Huston, Kelly Macdonald, Brad William Henke, Bijou Phillips, Gillian Jacobs, Joel Grey, Jonah Bobo 16 cert, Cineworld, Dublin, 92 min