THE BATTLE still rages over the overall merit of Star Wars: Episode III — Revenge of the Unfortunate Anagram. But one thing is not in dispute — the plank-like acting of Hayden Christensen, who plays Darth Vader. His portrayal of the most evil force in the galaxy has been likened to “a laidback surfer dude”, “an immobile puppet” and “a recently diagnosed haemorrhoids sufferer”. The key theme here has been the monumental inexpressiveness of the performance.

Great screen actors underplay. Bad screen actors overplay. In the middle, like a jellyfish you can prod forever with a stick, resides the Wooden Actor. Usually blessed with blandly pleasant looks, they can sustain careers with inert puréed inoffensiveness. Richard Chamberlain, Richard Todd, Michael Wilding, Michael York, Robert Cummings, Robert Taylor. Even the names are interchangeable.

Hayden Christensen was actually quite decent in Shattered Glass, the drama about a disgraced journalist. And in Episode III he has to struggle with already infamous dialogue while gazing into Natalie Portman’s dead-planet eyes.

“You’re so beautiful.”

“It’s only because I’m so in love.”

“No, it’s because I’m so in love with you.”

But when faced with terrible lines and a director with no interest in modulated performances, actors have to learn to protect their performance. They have to fill up for each scene, devise bits of business to sell the scene and summon up that extra voltage for the close-up, all without overacting.

This latter pitfall is not a problem for classically wooden actors. They are like those good-looking girls who grew up never having to develop a personality to attract attention.

With so many actors, one is looking for the off-switch: the hyperactive comedians, such as Robin Williams or Jim Carrey; or the shouting Method victims, such as Gary Oldman; or Al Pacino playing blind. But with the Wooden Actor, one starts off looking for the on- switch, then concludes that even if the lights were on, no one would be home anyway.

In the old days, with the heavy lacquer of English class, blandness was often camouflaged by the costive conventions of drawing-room drama. Everyone had to be so well-bred, it was hard to tell blandness from good manners.

The modern figleaf is the avalanche of special effects. But, as Star Wars proves, an iridescent CGI universe only highlights that organic quality of the truly wooden performance. The adjective is well chosen. Wood is after all technically alive, but how can you tell?

Superficially, a wooden performance is made up of the same elements as a great piece of underacting. Alain Delon, for example, seemingly does nothing in Le Samourai, his stoic minimalist 1967 gangster classic. He sits in his room, he feeds his pet bird, he wears a trenchcoat and he smokes. Occasionally he kills someone, but he doesn’t show much change in his features when he does. And yet it is a riveting piece of acting, fully charged with layers of buried emotion and longing, haunted with weary macho romantic fatalism.

Now compare it with, oh, any performance by Keanu Reeves, the world’s most famous wooden actor. Watching him convey thoughtfulness on screen is like watching a puppy scrabbling to get out of an empty bathtub. One day he’ll make it and it’s sort of fun to watch, but it never resonates with the filigree of heartache or the voltage of merry cunning.

Reeves is not a slacker. He really puts a lot of effort into his performances. He knits his brow and works himself up into the appropriate frenzy/rage/ardour. But he can never break free of his trademark sleepy befuddlement. He has, as the saying goes, no range.

Interestingly, the same can be said of many genuinely effective actors. Joel McCrea, a limited leading man, showed the way to triumph here. “People say I’m a one-note actor, but the way I figure it, those other guys are just looking for that one right note.”

Thanks to The Matrix Reeves’s one right note is cosmic befuddlement and he does have exotic features. If he had a more vanilla handsomeness, he’d now be with Billy Baldwin, Chris O’Donnell or Rob Lowe handing out leaflets at Democrat rallies. And Reeves does have that sense of mystery so vital for movie stardom that has nothing to do with conventional acting skill. While a guest at the Actors’ Studio, Burt Reynolds was asked to identify that vital ingredient. Reynolds, who was certainly a wry, sexy A-list king in his time, said he got the answer from Shelley Winters: “A sense of danger.”

Her litmus test was to ask of a leading man, even in the PC age: could you leave him alone with your girlfriend? (For scientific consistency, one has to assume a sober, non-predatory girlfriend.) A run-through of some incontrovertible stars — Sean Connery, Richard Burton, Clark Gable, Errol Flynn, Russell Crowe, Arnold Schwarzenegger — provides the answers: no, no, no, no, no, absolutely not.

Still, it is not a definitive test. Tom Cruise conveys plenty of menace on screen, but one feels any girlfriend would be safe during his babysitting shift. Conversely, no female should sensibly be left alone with Jude Law, but he has yet to convey really genuine threat on the screen. But with Christensen, one would feel considerably more relaxed. Likewise pretty much all of the plank hall of fame: York, Chris O’Donnell — and definitely Chamberlain since he came out in his memoirs. They all seem so nice, reasonable and helpful. It’s what you want in a neighbour, not in your hero.

Top ten wooden actors and dynamic duos (not)

BRING ME THE FIRELIGHTERS

1. Daniel Craig
2. Hayden Christensen
3. Richard Chamberlain
4. Gwyneth Paltrow
5. Michael Wilding
6. Michael York
7. Robert Cummings
8. Nicole Kidman
9. Kris Kristofferson
10. Lady Penelope

MEET MR AND MRS WOOD

Hayden Christensen and Natalie Portman (Star Wars Episode III: Revenge of the Sith) The probe to Mars found more signs of life.

Ben Affleck and Jennifer Lopez (Gigli) Dumb Mafia thug meets lipstick lesbian hitwoman. Watch the splinters fly.

John Travolta and Lily Tomlin (Moment by Moment) Beach bum woos Malibu housewife. They talk. A lot.

Sean Penn and Madonna (Shanghai Surprise) The light comic touch of Sean Penn and, er, Madonna.

Brooke Shields and Christopher Atkins (The Blue Lagoon) An island paradise uninhabited by humans — right till the end.

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