DANIEL CRAIG has it, as does Billy Bob Thornton. Harvey Keitel has had it for years, while the up-and-coming Laurent Lucas, the star of Who Killed Bambi? is the most explicit exemplar yet of that beguiling screen quality known to casting directors and industry pundits alike as “sexy-ugly”.

Originally popularised by the gender-bending rom-com Kissing Jessica Stein (which in 2001 introduced the term and made Keitel and James Woods its patron saints), sexy-ugly is ostensibly about charisma. It seems to describe an apparently aberrant physical appearance — too short, too long, too wide, too damn odd — but one that nonetheless defies 2,000 years of belief in Euclidian proportions and the pleasurable effects of human symmetry by being inherently, ineffably attractive.

Sexy-ugly has since become the apposite adjective not for just a few ageing craggy-faced Hollywood anomalies, but for an entire stratum of cinema’s newest leading men. Craig (Enduring Love), Adrien Brody (The Jacket), Paddy Considine (Dead Man’s Shoes) and Lucas are just some of the actors who, through sheer force of charisma, are challenging the hegemony of traditional square-jawed blue-eyed casting practises. And what’s more, they’re winning.

“Think of Paddy Considine or Adrien Brody,” says the casting guru Dan Hubbard, whose recent credits include The Lord of the Rings and The Bourne Supremacy. “These are often much more interesting actors to watch than conventionally handsome leading men. They walk through the door and it’s all in the way they carry themselves. There’s something about them, an X-factor that makes them fascinating to watch, and makes people want to see them on screen.”

A fellow casting agent, Lucinda Syson (Batman Begins, Troy), says: “They have more dimensions to them. You put a Daniel Craig up there, who’s not your Mr Pretty Boy, and suddenly the part becomes much more interesting.”

Considine, Brody and Craig are currently the gold standards for sexy-ugly, and in their recent performances as, respectively, brooders, loners and schemers, they’ve consistently added subtle layers of mystery and menace to roles that might otherwise have been emotionally denuded by a letter-perfect reading from the likes of Brad Pitt or Orlando Bloom (think about the terrifying stillness of Considine’s avenging angel in Dead Man’s Shoes, or Craig’s twitchy unravelling academic in Enduring Love).

But even these three have nothing on the 39-year-old Lucas. In all of his films, chief among them the hospital thriller Who Killed Bambi? and the stalker psychodrama Tiresia, he seems to hold his own appearance in some perpetual dance, effortlessly flipping back and forth between bright-eyed romantic charm and undershot Neanderthal aggression. In doing so he serves his characters to a degree that conventionally attractive types couldn’t possibly emulate.

“That’s exactly the point,” says Tiresia’s Bertrand Bonello who, having directed Lucas in three movies so far, is qualified more than most to discuss his protégé’s performance tics. “Laurent can seem to be handsome, and then suddenly very frightening. For me a good actor is someone who provokes desire. And desire is mystery. Laurent definitely has mystery.”

But why is it that these actors who in other generations would have been confined to the noble but hardly rewarding ranks of the gifted character actor (from Walter Brennan to Peter Lorre to Seymour Cassell), are now slowly taking centre stage? Hubbard suggests that the sexy-uglies, unable to trade on looks alone, have had to cultivate their X-factors in a way that clearly eludes their dashingly symmetrical counterparts.

“There are handsome stars who are also great actors, but often the handsome ones come in and over-act, because they’re trying too hard, because it’s not natural to them.”

Syson, however, hints at a growing maturity in the film business, which now recognises idiosyncratic talent, irrespective of appearance. However, this is a value judgment yet to be applied with the same rigour to the female ranks. “Where are the sexy-ugly women stars? In fact, where are the sexy-ugly women? I think we need to do some serious catching up, actress-wise,” she says.

Bonello, though, thinks that the truth runs deeper still. He says that the growing penchant for sexy-ugly male talent reflects a wider malaise in our culture. “Today, so many actors are boy-next-door types. A lot of actors are still like teenagers, even though they’re 35 or 40, and directors don’t want that. We want something with more mystery. We’re missing something that the actors from the Fifties had. What we’re missing, in a way, is ‘real men ’.”

Which is where sexy-ugly — all prognathous jaw, stubbed finger-nails and lop-sided grin — comes riding gallantly and charismatically to the rescue. In a movie culture where screen masculinity is often defined by pectoral implants, hair extensions, body-waxing, rhinoplasty and extreme orthodontic action, there’s something eminently reassuring about the unapologetic aquiline noses, crooked teeth and glorious asymmetry of these so-called “real men”.

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