Welcome to the world of the extra, or background artiste, as one is now obliged to call them. In their latest sitcom, Extras, Ricky Gervais and Stephen Merchant have plundered this world of aspirational bit-parters, desperate for their big break. And, as Gervais's character, a hopelessly ambitious bank-manager-turned-extra called Andy, is quick to find out, the only time anyone important notices an extra, is when they get something wrong.
"I remember once on Spy Game," recalls Lucinda Syson, casting director for Hollywood films such as Troy, "where there was one simple scene: Dale Dye was talking to Robert Redford. There was a chap in the background, an extra, who was meant to be reading a newspaper.
"But the director had to ask him to come out of shot because he was so awful. When it came to acting natural while reading a document, he couldn't do it. He turned the pages funnily and looked about too much. This guy - Mister Nobody from Nowhereland - was really distracting, and it was going to ruin the scene."
Perhaps the most famous Mr Nobody of all time made his starring role in Ben Hur, MGM's blockbusting 11-Oscar-winning sword-and-sandals epic of 1959. Hundreds of thousands had been spent on this one dramatic passage. Hundreds of extras were on an elaborate set, awaiting their megaphoned command. In the editing studio, the chariot scene would go down in the record books as the least economically shot section of any film, at a rate of 293ft of film for every foot used. But the scene will only be remembered for one thing - a trumpeting extra who forgot to take his watch off.
So who'd be an extra? Well, quite a lot of people as it turns out. "You do meet some wannabe professional 'actors' who are slightly ashamed of what they're doing," says Adam Smith, 39, a regular extra. "But I think most people treat it as good supplementary income. It attracts people from all walks of life. They're mostly self-employed or retired people with a creative bent."
And has he ever suffered for his art? "Definitely. I had to play rugby, in the nude, with a cabbage. It was for this cheesy soap called Mile High. We were meant to be military officers. There were three of us just chucking a cabbage around naked in the officer's mess. It was weird, but I got paid extra for it."
Juliet Diamond, 27, now a professional actor, recalls that working as an extra while she was at drama school brought its fair share of humiliations too. "I had to snog somebody in Messiah. He was one of the leads and he wasn't attractive. But they never used it in the final film. I thought, 'Lucky guy, he got a snog for free.' And I had to audition for that role. Talk about exploitation."
Many extras, though, are in it for quick cash, and the little add-ons assistant directors ask them to do are worth the embarrassment. Sam Ingleby, 25, now a teacher, was working as an extra on the set of Wimbledon when he heard from a runner that there was cash to be earned by getting his kit off for a shower scene. "Of course I got involved," he says. "It wasn't a huge amount over and above the 60-quid day rate, but I still did it. There were all sorts of those insider deals going on. A friend of a friend would know that they needed someone for a particular scene."
The set of Wimbledon was exactly the kind of environment exploited by Gervais and Merchant in Extras. Awash with hundreds of "non-named roles", because of the large crowd scenes, the potential for in-fighting and oneupmanship is limitless. The comedy duo were not far off the mark.
"I sat next to one poor girl who had her CV with her," recalls Ingleby. "It was all, like, 'Emmerdale: Extra', 'BBC Daytime Soap: Extra'. That was her whole life, her entire career. And Emmerdale was the best thing she had done." Another extra on Wimbledon, Jessica Pritchard, 25, now a wine journalist, had a similar experience. "We were all extras, but there were some hilarious 'background artistes'. They turned up with their own policeman costumes. I think they must have got paid more for them."
But Pritchard soon graduated from the ranks of extras to play a prominent role alongside Kirsten Dunst and Paul Bettany in the finished film. "That was weird," she says. "When I turned up I'd have been happy to be in the background, but I started to enjoy the scenes I was in with Kirsten Dunst. She had to wear platforms so that she didn't look too small next to me."
Pritchard was paid extra for her supplementary activities, much to the chagrin of the professionals who are looking for any opportunity to top up their standard day rate. So how much can you earn as a professional background artiste? "It's harder and harder to make a living as a full-time extra now," says Jon Winter of Lee's People, a leading extras agency. "There are more agents out there now, and the work is split among [them]. We have a pool of 5,000, so there are lots of people wanting to do it.
"But for a movie, the day rate starts at the union minimum of £69.43 a day, plus holiday pay - that's for a nine-hour day. You get upgrades for talking on camera, providing your own costume, that sort of thing. On average, our people are making £100 to £120 a day, which is good if you can do it every day, but that doesn't happen."
Forty years ago, being an extra was a full-time, well-remunerated career. In Picture, Lillian Ross's coruscating report of John Huston's 1952 American Civil War film The Red Badge of Courage, the author records these basic wages for extras - $10 a day basic; $25 if you have to play dead (day rate); a further $23 for speaking roles, however small; and a $5 bonus for any man sporting a beard. In new money, that means that for even the smallest, bearded, speaking part, an extra could earn £170 a day. Those with a beard who could spend a day playing dead while also landing a speaking role could really cash in.
While the pay may have been better in the golden days of the Hollywood union, the motivation for extras has never really changed. Ross recalls this brown-nosed exchange between one of the grande dames of the extras brigade, Burt, and his director on the final day of shooting The Red Badge of Courage:
"Huston strolled over, an unlit cigarette dangling from a corner of his mouth. Burt whipped out a match. 'Thank you, Benny,' Huston said. 'How you doin', boss?' Burt asked. 'Everythin' goin' all right?' 'Why, yes, thank you very much, Benny,' said Huston. 'You gonna rest up Bargin Lass?' Burt asked, referring to a horse in Huston's racing stable. 'Uh-huh,' said Huston, his mind obviously on something else. 'Well, now, Benny, I need a close-up for the next shot. You might be very good for it, Benny.' Burt could not contain his delight. 'Sure, sure', he said. Huston laughed and told him to be on the alert for a call."
But Burt never made it. And neither has the man with his own policeman's outfit on Wimbledon. So does anyone ever break through from being an extra to being a star?
"We've had people on our books who have gone on to do great things, but I wouldn't like to say who," says Winter. "They may get picked up by a casting director who is going for a particular look, and get given a line. It sort of snowballs from there."
"Of course it can happen," says Lucinda Syson, "just not often. And they don't tend to be the bona fide, back-of-the-shot, extras. They tend to be those who work in the grey area between being an extra and being a named part. But big names have been tiny parts. That's how everyone starts. I was flicking on a movie channel the other night and saw Samuel L Jackson playing a cigarette seller in some awful film. I couldn't believe it was him."
For the 99 per cent who do not graduate from being a cigarette seller to being a cult hero, there is nearly always work. But it's not always a laugh a minute. The one feature of being an extra that everyone who has ever worked in this field will tell you is that you do a lot of crosswords.
"My last day we were all sitting on Court No 1 filming one of Paul Bettany's big tennis scenes", says Sophie Redman, 21, who was sacked from Wimbledon. "I was so bored by then, we'd been doing it for two weeks. Anyway, they couldn't afford to fill all the seats with extras so they had dressed up mannequins and set them up in the rows. I happened to be sitting in between two of these mannequins. I fell asleep against one of them until someone on the set came over and asked me what my name was. At the end of the day when we went to sign out they told me not to come back."
There are scores of extras who jack it in, driven to distraction by the lack of anything to do. "It can be a bit miserable," admits Andy Smith, now a four-year veteran of the extra game. "You won't be called for days sometimes and you do a huge amount of sitting about. There is only so many times you can read Metro."
But there's always the possibility that someone, somewhere will spot you. And that is enough to keep thousands coming back for more of this cabbage-throwing, semi-naked, battered-corpse, everyday employment.