Truth be told, Bruce Willis has made far more bad movies than good. Which means it must be hell for Hollywood studios when it comes to giving him all that lovely moolah.
One minute he's a record-breaking stallion, the next he's a bank-breaking ass. Yep, Bruce Willis is the kind of guy who will merrily deliver a string of duds and then, suddenly, without much warning or logic, a worldwide blockbuster.
"When you've had a career like mine," smiles Willis, "you have to be able to laugh at yourself. And at the business itself. There are no guarantees, and you can only make the movies that you want to make, that you feel other people might want to see. And as you get older, all you truly care about is having some fun."
And it looks like Bruce Willis had a lot of fun making Cop Out, an unashamedly old-fashioned buddy-buddy cop comedy co-starring the leading comic light of TV's 30 Rock, Tracy Morgan. It harks back to the likes of 48 Hrs and Lethal Weapon, Morgan does his trademark Eddie-Murphy-on-acid routine while Willis tries his best to play the straight man. But even he has to join in on the fun.
In one memorable scene, Cop Out pays tribute not only to classic cop films but to cinema itself, as Morgan's Paul Hodges runs through a series of impressions during an interrogation. Willis's Jimmy Monroe claims not to know who he's impersonating when Morgan launches into John McClane's battle-cry of "Yippee-ki-yay, mother****ers". Shurely shome mishtake?
"Yeah, well, some one-liners are just hard to place, you know," laughs Willis. "We thought it would be fun to throw that one into the mix, because, you know, Die Hard is part of the vocabulary when it comes to cop pics. That's what was so great about this movie -- we were having fun, not only with the story itself and the characters, but with the genre, too."
As for Morgan and his celebrated comic surrealism, the native New Yorker has said it took a little while for his co-star to get used to his tempo. This is, after all, the man whom David Letterman reckons "may not be hooked up right".
"And I concur," nods Willis. "But Tracy's crosswires are what makes him spark, they're what make him different. You never quite know how Tracy is going to play a scene, and the one thing you have to be very, very careful about is not laughing. Because he's full of surprises.
"He's like a hyperactive child when it comes to the comedy, always ad-libbing, always finding new ways to deliver a line, new ways to play a scene. It keeps you on your toes, so, yeah, I had to adjust my set a little to get used to that."
It was Morgan's taste for the surreal and pushing at the boundaries, that led to the actor's favourite scene in the movie --where he punches an 11-year-old boy in the groin. Has Willis got any personal highpoints when it comes to Cop Out?
He takes a moment before answering. "You know, I think it might have been watching Tracy Morgan punch an 11-year- old boy in the groin," he grins.
"To be honest, I had lots of scenes where I just fell about laughing, just because Tracy kept surprising everyone, especially me. Thankfully, being the pro that I am, most of them made the film, but the outtakes are going to be interesting."
What will surprise many about Cop Out is the fact that the man behind the camera is Kevin Smith, the outspoken and outsized writer/director of Clerks, Mallrats and the Jay And Silent Bob movies, stepping into director-for-hire mode for the first time.
"I think Kevin didn't want to set out to make a Kevin Smith film," says Willis. "He wanted, just like I did, just like Tracy did, to make a film that celebrated the 1980s cop thriller comedies. I know Tracy has always held films like 48 Hrs close to his heart, and that's something that Kevin took on board. Having a wicked sense of humour was important here too, of course. I think Kevin did a great job, by the way"
Nonetheless, the critics haven't been quite so kind, Cop Out scoring a lowly 19pc on rottentomatoes.com.
The general word is 'lazy'. Followed by 'derogative'. And then 'jaded'. What are they talking about, Willis?
"I think there's an automatic assumption that if you make a movie like this that pays tribute to a genre that isn't held in the same esteem as film noir or grindhouse, or whatever, the critics think you're just making a run-of-the-mill commercial film.
"Perhaps if we'd shot it all in sepia and put up Italian subtitles, they might have liked it. As it is, Cop Out was just too easy-going for most of them to see that quite a bit of thought went into making it seem so easy-going."
Talking of easy-going, despite suffering the ups and downs of your typical Hollywood career, Bruce Willis never seems to be particularly ruffled. Or maybe there's an awful lot of running, sweating and swearing going on behind the scenes?
"Well, I try to run only when I want to," smiles Willis, "and the same goes for sweating and swearing, so, no, there isn't too much effort going on behind the scenes. I think I know what I'm doing at this stage, and how I want to do it."
That sense of calm extends to his extended family. Bruce's ex, Demi Moore has been happily married to young buck Ashton Kutcher for almost five years now, while Willis remarried in March of last year, getting hitched to Emma Heming, a 31-year-old Maltese-born actress. What's the secret of Bruce Willis and Demi Moore continuing to be great friends when both have moved on to other relationships?
"It's just about friendship and respect, you know," he offers. "There's no horror between us, there are no dark secrets, no crushing regrets. We both lead happy, healthy lives, and being around one another, for our kids, for our friendship, is an important part of that. I guess it helps that the man she's with now is a great guy; Ashton's an important part of this big family. And Emma's not too bad either, of course . . ."
Willis lets out a laugh. A busy man these days. Coming soon, Bruce has got the all-star, all-ages action-hero ensemble piece The Expendables; he co-stars alongside Morgan Freeman in Red; possibly Catch 44 for writer/director Aaron Harvey; there's Kane & Lunch with Jamie Foxx; and The Last Full Measure for writer/director Todd Robinson. So, I'm guessing Bruce Willis isn't exactly bored with this acting lark just yet?
"No, still finding movies I want to make, roles I want to play," he nods. "I'm happier now than before, I think, and that's just because I know the system so well. I don't fret as much as I used to."
Cop Out hits Irish cinemas next Friday