an on-the-lam comedy in which our mismatched heroes – one humbled, the other a wiseass, both vintage blunderers – flee the authorities and kingpins alike.

With its playful funk score by Christophe Beck and a plot that becomes a tangle of Elmore Leonard-style mishaps, the film often operates like Soderbergh Lite.

Liman assembles an ace cast of character actors to play the various strands of his small-time Boston crime empire, including Michael Stuhlbarg, Alfred Molina, Toby Jones, Paul Walter Hauser, and Ving Rhames as a cucumber-cool fixer on the Boston boys' tail.

The ensemble is so stacked with effortless talent that you barely mind how arbitrary the corruption storyline connecting everyone is.

If this were an actual Soderbergh movie, it would have a clearer point to make about the intersection of blue-and-white-collar crime.

Affleck and his co-writer, Chuck Maclean, are sharper on the small, farcical details, like a long debate about how much manpower you can always expect behind the wheel of an armored truck.

Rory and Cobby, who never entirely stop bickering, end up yanking Rory's shrink into the action, not so much taking her hostage as giving her some plausible deniability to help a couple of bumbling fugitives.

Continuing her streak of being believable in just about everything, Hong Chau sells the predicament of a mental-health professional torn between following protocol and doing what is best for her client.

Her calming presence and on-the-fly sitcom diagnoses underscore the larger problem with 'The Instigators.

' Rory and Cobby do not seem particularly worried, even when narrowly slipping out of the crosshairs of men who want them dead, and that is probably because they are never actually in any danger.

For all its gunplay, explosions, and multi-car chases, 'The Instigators' is too committed to its good vibes to flirt with real urgency.

It is a crime lark so relaxed it practically slips the audience a sedative.

Liman, who ushered Damon onto the action-hero A-list a couple of decades ago, finds ways to blow money.

There is a climactic heist involving fire trucks that probably cost as much money as the characters are trying to steal.

But on the whole, 'The Instigators' is closer in chatty, small-scale spirit to the director's debut, with Damon in the Jon Favreau role and Affleck bringing some of the sardonic attitude of Vince Vaughn.

Though packed with familiar faces, the movie really comes down to the clashing personalities of its stars, who bring the familiarity of childhood companionship to a couple of strangers bonding over their escalating bad luck.

With apologies to Ben, this might be the Damon/Affleck pairing worth revisiting.

Though they have appeared in multiple movies together over the years, Matt Damon and Casey Affleck have only just now arranged a showcase for their lifelong personal and creative rapport.

'The Instigators' casts the two as contrasting screw-ups who go on the run after a heist gone wrong, with a bunch of cops and criminals played by famous character actors in hot pursuit.

Director Doug Liman brings a certain discount Steven Soderbergh energy to the action, but the perennially laid-back quality begins to seem more of a liability than a merit.

This buddy comedy lives or dies on your affection for its stars, offering complementary shades of good-natured Bostonian ineptitude.