Sylvester Stallone and his cast of fellow action stars flex substantial ensemble muscle in this high-energy battle between good mercenaries and bad mercenaries. An effective mix of lean and over-the-top, "The Expendables" is often preposterous, but it achieves the immediacy of a graphic novel without the overdone mythology.

Genre fans for whom there’s no such thing as overkill will make it a fearsome contender at the boxoffice when it opens stateside Aug. 13. The director/star’s newest since "Rambo" is also sure to be a muscular performer in international markets.

Even when they’re going for the obvious laugh or comeuppance, Stallone and his co-writer, David Callaham, use deft shorthand to etch their characters in bold outline, and the actors put their well-defined personas to work to complete the process.

A group of freelance warriors who have lost their connection to righteous causes in favor of almighty cash, the Expendables may be hardened, but they’re not yet inhuman.

Leader Barney (Stallone) regards friends and enemies alike with a sad gaze (beneath strangely distracting eyebrows). Knife whiz Lee Christmas (Jason Statham) is man enough not to hide his hurt over a busted relationship, while combat expert Ying Yang (Jet Li) is angling for a raise.

In smaller roles, Terry Crews and his biceps handle the operation’s biggest weapons, and Mixed Martial Arts star Randy Couture explains things, like his cauliflower ear, in fine scientific detail.

After the high-body-count rescue that opens the film, Barney chooses to cut loose sniper Gunner (Dolph Lundgren), believing his (unseen) drug use and high volatility make him untrustworthy — a conviction that’s soon validated when Barney and Gunner are on opposite sides in a clobbering car chase.

A couple of women figure in the story, but the subject is really the ties, broken and otherwise, in this brotherhood of latter-day samurais. In the film’s most nuanced scene, Mickey Rourke, ultra-charismatic as the ex-Expendable whose tattoo parlor serves as HQ and clubhouse, recalls the moment in Bosnia when he knew his soul had dried up.

The mission that wakens Barney’s dormant compassion involves the fictional South American island country of Vilena, where a former CIA operative, Monroe, pulls the puppet strings of dictator Gen. Garza (David Zayas, of "Dexter"). As the icy evil-in-a-suit rogue Munroe, you couldn’t do much better than Eric Roberts.

Determining that if they take out the general they’d be sacrificing themselves to save the CIA embarrassing headlines, Barney and his boys turn down the assignment. But then he meets the general’s beautiful rebel daughter, Sandra (newcomer Giselle Itie, suitably fiery), and for the first time in years, money isn’t everything.

Americans are both heroes and villains in "The Expendables," which avoids political specifics while embracing brute force as righteous retribution — and shows the bad guys resorting to waterboarding. It can be an uneasy mix, but mostly it’s played on too broad a scale to take seriously. DP Jeffrey Kimball frames the action for kinetic impact and velocity. The extended fight scenes deliver the easy catharsis of straight-up violence, all with a comic-book sense of pow and splat.

The winking boys-will-be-boys quality is at its most blatant in a scene containing uncredited cameos by Bruce Willis and the moonlighting Governator. (Outside the film’s Los Angeles premiere, California state workers protested their pay cuts by Arnold Schwarzenegger, but most action-film fans will probably delight in the scene’s self-consciously starry chemistry, and its punchline.)

Production designer Franco-Giacomo Carbone’s evocative sets and locations (in Los Angeles, Louisiana and with Brazil playing Vilena) enhance the body blows and the camaraderie. Even with action writ large, though, Brian Tyler’s score too often reaches for bombast.

Opens: Friday, Aug. 13
Lionsgate and Millennium Films present a Nu Image production
Cast: Sylvester Stallone, Jason Statham, Jet Li, Dolph Lundgren, Eric Roberts, Randy Couture, Steve Austin, David Zayas, Giselle Itie, Charisma Carpenter, Gary Daniels, Terry Crews, Mickey Rourke
Director: Sylvester Stallone
Screenwriters: David Callaham and Sylvester Stallone
Story by David Callaham
Producers: Avi Lerner, John Thompson, Kevin King Templeton
Executive producers: Danny Dimbort, Boaz Davidson, Trevor Short, Les Weldon, Jon Feltheimer, Jason Constantine, Eda Kowan, Basil Iwanyk, Guymon Casady
Director of photography: Jeffrey Kimball
Production designer: Franco-Giacomo Carbone
Music: Brian Tyler
Co-producers: Robert Earl, Matt O’Toole
Costume designer: Lizz Wolf
Editors: Ken Blackwell, Paul Harb
MPAA rating: R, 104 minutes