Robin HoodThere will be plenty of opportunities this summer to learn whether movie stars still exist.

Well, they exist, but do they still matter at the box office? Conventional wisdom in Hollywood has it that stars don't matter anymore, that moviegoers are drawn to the theater not by stars but by pre-sold concepts (sequels, adaptations of familiar titles, special effects showcases, simple horror premises, family-friendly animation, or anything requiring 3-D glasses). Star paychecks are dwindling, since even once-bankable A-listers have been faltering with mainstream moviegoers.

This summer, several top stars who've gone hit-less in recent years will get a chance to prove they can still sell tickets. (First up: Russell Crowe, whose dry spell has lasted three years, in this Friday's 'Robin Hood.') Almost all of these stars are falling back on traditional action heroics to revive their careers; even Will Ferrell's movie is a buddy-cop comedy. (Notable exception: Julia Roberts, who's never had to karate-chop a bad guy and isn't about to start now, is going the chick-flick route.)

Can they pull it off? After the jump, we handicap the summer comeback vehicles of eight A-listers. Cross your fingers. Robin HoodThere will be plenty of opportunities this summer to learn whether movie stars still exist.

Well, they exist, but do they still matter at the box office? Conventional wisdom in Hollywood has it that stars don't matter anymore, that moviegoers are drawn to the theater not by stars but by pre-sold concepts (sequels, adaptations of familiar titles, special effects showcases, simple horror premises, family-friendly animation, or anything requiring 3-D glasses). Star paychecks are dwindling, since even once-bankable A-listers have been faltering with mainstream moviegoers.

This summer, several top stars who've gone hit-less in recent years will get a chance to prove they can still sell tickets. (First up: Russell Crowe, whose dry spell has lasted three years, in this Friday's 'Robin Hood.') Almost all of these stars are falling back on traditional action heroics to revive their careers; even Will Ferrell's movie is a buddy-cop comedy. (Notable exception: Julia Roberts, who's never had to karate-chop a bad guy and isn't about to start now, is going the chick-flick route.)

Can they pull it off? Below, we handicap the summer comeback vehicles of eight A-listers. Cross your fingers.

Russell Crowe
Last Hit: 'American Gangster' (2007)
Recent Misfires: 'Body of Lies' (2008), 'State of Play' (2009)
Comeback Attempt: 'Robin Hood,' a gritty take on the Sherwood legend
Release Date: May 14
Chances for Success: Fair. Movie reteams him with Ridley Scott, who directed two of Crowe's biggest hits ('Gladiator' and 'American Gangster'), as well as two of his bigger flops ('A Good Year' and 'Body of Lies'). Role is the sort of action-hero-with-a-chip-on-his-shoulder type that Crowe fans like, but his Robin Hood will have to battle against Robert Downey Jr.'s still-mighty 'Iron Man 2' for the same audience of action viewers.

Jake Gyllenhaal
Last Hit: 'Brokeback Mountain' (2005)
Recent Misfires: 'Zodiac' (2007), 'Rendition' (2007), 'Brothers' (2009)
Comeback Attempt: 'Prince of Persia: The Sands of Time.' an action saga based on the videogame
Release Date: May 28
Chances for Success: Decent. If anyone can turn a thin premise into a lavish action/fantasy hit, it's producer Jerry Bruckheimer, who did the same with 'Pirates of the Caribbean.' Too bad the demographic groups that like to see Gyllenhaal bare-chested will be going to see 'Sex and the City 2' that weekend.

Tom Cruise and Cameron Diaz
Last Hit: Cruise: 'Mission: Impossible III' (2006); Diaz: 'What Happens in Vegas' (2008)
Recent Misfires: Cruise: 'Lions for Lambs' (2007), 'Valkyrie' (2008); Diaz: 'My Sister's Keeper' (2008), 'The Box' (2009)
Comeback Attempt: 'Knight & Day,' an action comedy about a secret agent (Cruise) who falls for a regular gal (Diaz); think 'Mission: Impossible' meets 'Jerry Maguire.'
Release Date: Jun. 25
Chances for Success: Hmm. Cruise sells the most tickets when he's a straight-up action hero, and the romance angle could work if the script and chemistry are right. But the last time he acted opposite Diaz, the result was 'Vanilla Sky.'

Angelina Jolie
Last Hit: 'Wanted' (2008)
Recent Misfires: 'A Mighty Heart' (2007), 'Changeling' (2008)
Comeback Attempt: 'Salt,' a spy thriller originally written for Tom Cruise
Release Date: Jul. 23
Chances for Success: Good. Role returns her to the slinky, acrobatic action heroics that her fans like ('Wanted,' 'Mr. & Mrs. Smith'). Given the film's release date, she should have late summer pretty much to herself.

Will Ferrell
Last Hit: 'Step Brothers' (2008)
Recent Misfires: 'Semi-Pro' (2008), 'Land of the Lost' (2009)
Comeback Attempt: 'The Other Guys,' a buddy-cop spoof co-starring Mark Wahlberg
Release Date: August 6
Chances for Success: Pretty good. If anything can cleanse the still-lingering stink of 'Land of the Lost' off of Ferrell, it's a movie directed by Adam McKay, who's helmed some of Ferrell's best-loved work ('Anchorman,' 'Talladega Nights,' 'Step Brothers'). Wahlberg has never starred in a comedy before, but he's earned praise for his comic supporting turn in 'Date Night.' In early August, there are no other major comedy contenders.

Julia Roberts
Last Hit: 'Ocean's 12' (2004)
Recent Misfires: 'Charlie Wilson's War' (2007), 'Duplicity' (2009)
Comeback Attempt: 'Eat Pray Love,' a drama based on Elizabeth Gilbert's best-selling memoir about her worldwide quest for solace in the wake of her divorce
Release Date: August 13
Chances for Success: Very good. The book's countless fans should make this the chick-flick event of late summer. Plus, Roberts doesn't have to share the spotlight too much, though she reportedly generates good chemistry with Javier Bardem.

Sylvester Stallone
Last Hit: 'Rambo' (2008)
Comeback Attempt: 'The Expendables,' an action movie about a band of mercenaries, whose cast includes fellow '80s throwbacks Bruce Willis, Mickey Rourke, Dolph Lundgren, and (taking a break from his day job) Arnold Schwarzenegger.
Release Date: August 13
Chances for Success: Okay. This is the very definition of a comeback movie, given the cast and the novelty of a scene that unites '80s action icons Stallone, Willis, and Schwarzenegger on screen for the first time. Stallone has had modest hits in recent years reviving his signature Rocky and Rambo characters, but he's had little success playing anyone else. Still, at this late date, action fans won't have another choice.

• Follow Gary Susman on Twitter @garysusman.