Writers have been documenting the incredible shrinking movie star for decades. Google “the last movie star,” and not only will you find serious musings about George Clooney, Will Smith, and Tom Cruise, but thoughtful ones about Elizabeth Taylor. Hyperbole about imminent extinction aside, movie stars have shrunk as the films have grown bigger and louder. Just look at the box-office results from last year. Thirteen of the top 15 films were sequels, franchise starters, or animated films that don’t always require or even want stars. So far this year, The Hunger Games has proven once again that you don’t need a huge international star like Smith, Cruise, or Brad Pitt to mint box-office millions, and The Avengers cruised past a billion dollars with stars predominantly of Marvel’s own creation. Meanwhile, Johnny Depp, one of the other famous faces currently chiseled in Hollywood’s hypothetical Mt. Rushmore, learned that makeup, eccentricity, and Tim Burton do not always connect, as Dark Shadows opened poorly and is limping home. It all begs the question: Are movie stars still essential? And as the current class of elite stars inches towards 50, who is poised to save the planet and catch the bad guy while kissing the girl?

Screenwriter William Goldman once defined a movie star as an actor or actress who can reliably open a movie at No. 1, and that definition still holds. But there is a hierarchy. “There are not too many people who can pull off the list of things that you need to be to be a male movie star,” says Lionsgate’s president of production, Erik Feig. “First, be a good actor. Second, look like you can actually do those things, like jump from one building to another. Three, you have to have onscreen chemistry with your female costar. And four, you have to go out there and promote the movie. Just look at Tom Cruise on all the talk shows when he was promoting the last Mission: Impossible, and you realize, ‘My God, that’s why he’s Tom Cruise.’ There are a lot of great actors, but there aren’t a lot of movie stars.”

Cruise. Depp. Smith. Pitt. There are other major draws — Robert Downey Jr., Denzel Washington, Meryl Streep more than ever before — but those four are in a class by themselves. That’s not a box-office guarantee — did you race out to see Lions for Lambs or The Assassination of Jesse James? — but in a four-quadrant action film that is going to cost a studio nine figures, they are insurance against catastrophe. They have a proven track record and their names are important to foreign markets, which can make or break the picture. (More than 70 percent of Men in Black 3’s box office so far is international. The “disappointment” that was The Tourist cleared more than $210 million abroad.) “Everybody’s looking at international these days, so you have to have stars or it has to be a special-effects event movie,” says The Weinstein Company’s president of production, Dylan Sellers. “You have to have one of the two.”

“There is always going to be a need for the movie star in theory, because it’s that little speck of mystery and glamour that fuels the public fantasy,” says a top Hollywood casting director who’s worked on a billion-dollar franchise. “These movie stars are the flame that draws the public, like moths, towards the shiny objects that our industry is churning out and asking the people to pay their hard-earned money to see.”

But the increasing eventification of Hollywood films seems to have cost stars some of their clout. Today, a studio can launch a billion-dollar franchise, like Harry Potter, Transformers, or Avatar without a movie star. “You used to lead much more with the star — just a face on the poster,” says Feig. “And I think right now we are in a time [where] the market is about ‘What is it?’ not ‘Who’s in it?’… What’s the most popular video on YouTube? One little kid biting another little kid’s finger. That’s the thing people are interested in: What is it?”

Even a franchise like Batman, with a revered star like Christian Bale, is a prime example of this growing sensibility. “I think Batman would succeed with a number of actors, to be quite honest,” says one studio exec. “Christopher Nolan is the star of Batman just as Michael Bay was the star of Transformers.”

It’s impossible to tell for sure how Batman Begins and its two sequels would have performed without Bale, but it’s fair to say that as excellent as he was in films before being cast as Bruce Wayne, and as brilliant as he’s been since — winning an Oscar for The Fighter — Bale lacked a brand. That fact likely helped him win the role in the first place, and even after taking the caped crusader to such great heights, it’s part of the reason Bale is still able to slip in and out of roles like a chameleon.

In that regard, Bale is a fascinating contrast to Leonardo DiCaprio, who is already in the elite movie star club — when he chooses to be. When he takes a break from less mainstream fare, like J. Edgar and Revolutionary Road, and agrees to tackle a role like the one he played in Inception, he’s as valuable a star as there is in the business. Playing the Great Gatsby in Baz Luhrmann’s upcoming adaptation is a potential movie star role that will showcase all his big-screen talent and beauty, and the thrill of watching him play deliciously evil in Quentin Tarantino’s Django Unchained promises to lure in fans who otherwise might not be interested. “There’s something unique and marvelous about his performances all the time,” says one studio exec. “But what is interesting is that consistent across all of them, there’s ‘Leonardo DiCaprio.’ You can really spot him in those roles. On the other hand, one of the things I find so interesting about Christian [Bale] is he disappears into those roles. He embodies his characters so unbelievably vividly and in their moment and true and authentic to their settings. And the actor who is bringing them to life has just disappeared. So I find them very different actors, but I’m always thrilled to see what they do.”

Both actors are in their primes, the mid-30s range when stars are young enough to play the dashing hero yet experienced enough to have accumulated enough influence to have a real say in the movie-making process. And as Cruise/Smith/Depp/Pitt get a little older — their average age is 47 — DiCaprio and Bale seem to be at the top of the list for the roles that keep Hollywood rolling in dough. They aren’t the only names in the mix, though. Looking around at this year’s major offerings, you get the sense the studios are already auditioning the next generation of action heroes.

NEXT PAGE: Who’s ‘the next Brando’?

So far this year, two young guns have made headlines — for very different reasons. Taylor Kitsch, 31, graduated from Friday Night Lights and quickly landed two major roles in FX-heavy alien adventures that, combined, cost more than $450 million to make. But both John Carter and Battleship bombed. Meanwhile, Channing Tatum, 32, delivered in the year’s biggest comedy (21 Jump Street) and the year’s biggest romance (The Vow), and is set to strip down in Magic Mike. The buzz around him reportedly encouraged Paramount to delay its G.I. Joe sequel so it could inflate his character’s role. The Wachowski brothers also took notice, casting Tatum in their next big sci-fi movie, Jupiter Ascending.

Based on conversations with several industry decision-makers, it’s clear that Kitsch, who still has Oliver Stone’s Savages slated for release July 6, has cooled, but Hollywood hasn’t exactly turned its back on him. “If those movies had really worked, I don’t know that anyone would have laid 100 percent of the credit at his feet either,” says one studio exec. “So for those movies to not have worked to the level of expectation, I wouldn’t put the blame at his feet. There’s probably a whole bunch of mysterious reasons why those movies didn’t work out. Would those movies have performed much differently with Chris Hemsworth? I don’t know.”

Kitsch’s case isn’t unlike that of his fellow Canadian, Ryan Reynolds, who suffered a setback when Green Lantern failed to shine last summer. Last winter, he recovered nicely in Safe House opposite Denzel Washington, and many insiders remain high on his future. “Women adore him,” says one exec, suggesting his strengths might play better in charming romantic comedies, like The Proposal.

Hemsworth the Elder, 28, a.k.a. Thor, is another up-and-comer who has studios hurrying to place him in their tentpole films. He convincingly played a Norse god in the Marvel superhero films (but more importantly, he held his own on the screen opposite Downey Jr.). He also helped Snow White and the Huntsman open, and he just wrapped the Formula 1 racing film Rush for Ron Howard. Meanwhile, his younger brother Liam, 21, has at least two more Hunger Games films and a slew of big-time action movies on the way.

Credit: Lewis Jacobs/NBC

The other hot name right now — and sure to be even hotter come July 20 — is Tom Hardy. The Inception supporting player, 34, has the unenviable task of following up Heath Ledger’s Joker performance as the next Batman villain, Bane, but everyone seems to be expecting another powerful performance from the Englishman who wowed critics in Warrior and Bronson. “The next Brando,” says one studio exec. That aura didn’t seem to boost This Means War, opposite Chris Pine and Reese Witherspoon, but his upcoming role as Mad Max in the Road Warrior reboot will be a better litmus test.

The biggest wild card in this Hollywood parlor game is already a movie star — at least on the Internet. Ryan Gosling, 31, had an incredible 2011, solidifying his bona fides with bravado performances in Crazy, Stupid, Love, Drive, and The Ides of March — none of which made more than $85 million at the box office. “He’s an artist, for sure,” said one studio exec, who was offering a compliment and describing a flaw. Still, Gosling has that thing. “The reason I think there’s such fervor over Ryan Gosling is that there is such an effortlessness to his acting that just seems cool. Cool like a young Paul Newman,” says another studio exec. “You’re seeing someone who’s just so good at what he is doing, and I think he’s making really interesting career choices, but I don’t know if he wants a Dark Knight. But let’s put it this way: If I had a Dark Knight, if I were working with a Chris Nolan type and I had a big marquee franchise character, I would go to him.”

More than one studio executive mentioned Jennifer Lawrence, 21, as the most promising — male or female — in this new class of aspiring movie stars. “After seeing what she did in Hunger Games and then what she did for us in Silver Linings Playbook, I don’t know if there’s anyone I’d rather be in business with than her,” says Sellers. “She can do action. She’s funny. She’s a terrific actress. We were blown away by her. We believe she is a big, big star.”

It’s interesting to see Lawrence mentioned next to Hardy, Hemsworth, and Gosling in the possible next-big-thing list. Huge A-list action movies have historically been a bit of a boys club, but Angelina Jolie proved — in films like Wanted and Salt — that a woman can be just as fierce and indomitable as the guys. Now, with Hunger Games, Snow White, and The Girl With the Dragon Tattoo, Hollywood seems more eager to embrace this more courageous heroine.

Of course, it would be premature to anoint Lawrence as a megastar until she headlines a smash not set in Panem. Tobey Maguire, Robert Pattinson, and Daniel Radcliffe were also centerpieces to enormously successful franchises, but none of them has yet graduated to the elite level. Once upon a time, Tom Cruise starred in Top Gun, and Will Smith struck it rich in Independence Day. But what separated them from their peers was Cocktail, Jerry Maguire, Hitch, and The Pursuit of Happyness, films that relied more heavily on their innate ability to fascinate and mesmerize us.

Some day soon, Lawrence, Gosling, or Tatum might join this exclusive club, but the current members aren’t going anywhere soon. The milestone age of 50 for a movie star is not necessarily the same 50 it is for you and me. (Heck, look at the recent action roles of Liam Neeson.) And even if they slip, they’re perfectly positioned to rebound. “Once a star, always a star,” says Sellers. “You see it all the time. I mean Travolta is one movie away. They all are.”