This seems launchable, so barring any objections I'll do so in 24 hours. So, let's say we've got at least two actors, with about the same level of success and popularity. They might be interested in making similar projects, have starred in similar roles, or may even be buds and want to make a film together; in any case, it is certain that people will love to see these two in a movie together to watch them go at it. Thus, we get a Dueling Stars Movie, a film whose entire reason for being (and the main reason to see it) is to see "those guys" together. It should ne noted that a film starring two bankable actors doesn't automatically qualify as a DSM. Htere are a few qualifications that must be met: 1) The stars must be about equal in success and popularity. For instance, Lethal Weapon is not a DSM: people didin't say "Aw man, Mel Gibson and Danny Glover are making a movie together, I gotta see this!"; Gibson provided the star power here (in fact, this is the movie that made Glover a star). Similarly, Rush Hour wouldn't be considered this either: people didn't give a damn about seeing Jackie Chan and Chris Tucker going at it, they wanted to see Jackie Chan kick ass, and Tucker was along for the ride. 2) We are interested in seeing the film not only for the characters the actors play, but primarily to see them. People didn't go to see Lethal Weapon to watch Gibson and Glover play off each other, they went to see Murtagh and Riggs do that, which is an important distinction, ditto for Rush Hour. In the same vein, while movies like Harry Potter and XMen may have big name stars to their credit that we love to see together (Alan Rickman, Jason Isaacs, Kenneth Branagh, etc. for the former; Ian Mc Kellan and Patrick Stewart for the latter), we don't go just to see them, we go to see Snape, Magneto, Professor X, and so on. Now Face/Off, on the other hand, is perhaps the Most Triumphant Example of this trope. The sheer awesome ridiculousness of the plot was just icing on the cake; what pepole really wanted to see was Nicolas Cage vs. John Travolta to see who could chew the most scenery and blow up more stuff. Of course, a DSM need not be merely a action-blockbuster; sometimes we can get films where we actually want to see the stars act: The Lion in Winter is a good exapmle of this, as the main draw is seeing two of the best actors in Hollywood (Peter O'Toole and Katherine Hepburn) give it their all while they verbally eviscerate each other for two hours (Hepburn actually won Best Actress at the Oscars for her performance). In short, this trope could be thought of as Just Here for Godzilla as applied to the film's stars, and as a result is practically made of And the Fandom Rejoiced. It will very often (nay, almost nevitably) involve copious amounts of Feed Me, with the stars often making glorious hams of themselves, to the point that the whole movie can be made of pure, juicy meat. A Sub-Trope of All-Star Cast.
- The Lion in Winter
- Ocean's Eleven: Nobody cares about watching Danny Ocean and his crew rob a casino; they want to see George Clooney, Matt Damon, Brad Pitt and company rob a casino.
- Heat and Righteous Kill, which were made soley so Al Pacino and Robert De Niro could be onscreen together.
- Forget that white kid from Boston (who's supposed the film's main character), the advertising for The Forbidden Kingdom was all Jet Li and Jackie Chan, which is really the only reason to see it.
- Hell In The Pacific: James Coburn vs. Toshiro Mifune as American and Japanese soldiers stranded on an island together? Oh, hell yes.
- The upcoming The Expendables is fueled by this.
- The Towering Inferno with Paul Newman and Steve McQueen, for which "diagonal billing" (one person's name top left, the other's lower right) was invented. In fact, at McQueen's insistance, they were paid exactly the same and had the same number of lines.
- Moon Child, starring Japanese Visual Kei superstars Gackt and Hyde (of L'Arc~en~Ciel fame). And the fangirls rejoiced.
- The Bucket List, because who wouldn't want to see two of Hollywood's most beloved actors on-screen together?
- Tango And Cash: Sylvester Stallone and Kurt Russell team up to kick ass? Yes please.
- The Prestige, while adapted from a novel, has it's main attraction in seeing Christian Bale and Hugh Jackman screw with each other (and no, not that way). Having David Bowie and Andy Serkis certainly didn't hurt, either.
- Mr. & Mrs. Smith (2009), or Brad Pitt and Angelina Jolie Fight Each Other And Do Sexy Things
- War was basically an excuse to see Jason Statham and Jet Li duke it out.
- Two of Hollywood's most famous examples are Butch Cassidy and the Sundance Kid and The Sting, where Robert Redford and Paul Newman get into dangerous situations and act manly together.
Hello, Unknown Troper. You'll need to get known to lend a hand here.