The first laugh doesn’t give it all away. Kyra Sedgwick, playing a New York TV reporter, shows up to cover the would-be suicide of the “Man on a Ledge.” She finishes her breathless report, and then, with more than a hint of Rita Moreno sneaking into her voice, the WASPy Sedgwick says, “Suzie Morales reporrrrrting.”

Well, snicker.

Then we see Genesis Rodriguez, who as Angie has shown up to pull off an elaborate jewelry-store burglary in “Lara Croft: Tomb Raider” togs — lots of skin and a push-up bra whose engineering only NASA could appreciate. Tee hee.

A guy’s standing on a ledge of the Roosevelt Hotel, threatening to jump, and the gum-snapping New Yorkers below yell “Just get ON with it.”

“Man on a Ledge” isn’t a caper comedy. It’s a heist picture, a thriller, and a not-that-thrilling one at that. But the folks who made it have enough of a sense of humor to get how silly it is and run with that on occasion.

Sam Worthington (“Avatar”) has the title role, a guy who broke out of prison just days before, an ex-cop standing on that ledge, proclaiming his innocence and demanding that the most unstable, hard-drinking negotiator on the NYPD (Elizabeth Banks) clock in to talk him down. In a few brisk early scenes, we see the prison break, meet the jumper’s brother (Jamie Bell) the brother’s girlfriend (Rodriguez), and the jumper’s former partner (Anthony Mackie). We realize, long before the cops, that this is no mere suicide. Nick Cassidy, standing on that ledge, is drawing attention and coordinating a heist as he does it. “Man on a Ledge” gambles that it can let us stay two steps ahead of the cops (Edward Burns, et al) and yet two steps behind its own twists long enough to work.

The villain is played with venomous relish by Ed Harris, a robber-baron developer/jewelry mogul ripped straight from today’s zeitgeist. He’s a rich guy who figures he doesn’t have to play by society’s rules. And the Pablo F. Fenjves script is perfectly pithy, even when its plots twists don’t quite live up to Spike Lee’s “Inside Man.”

“My choice, my only choice, is easy — to jump or not to jump,” Nick declares. Worthington only rarely suggests the end-of-his-tether mania that would be this jumper’s disguise. He’s playing a guy who isn’t that convincing as an actor.

You’ve got to love lines like “Women jump for love, men jump for money,” and the villain’s marching orders for business in New York — “In this city, on this island, we don’t go to work. We go to war!”

It’s hard to take any of it too seriously, and Danish director Asger Leth, son of Danish director Jorgen Leth, doesn’t. There isn’t much pace to his “ticking clock” thriller.

The absurdities begin with the moment Nick checks into the hotel — “Room 2505,” yet somehow, later, it’s “We got a jumper on the 21st floor!” Leth’s real gamble is that there are enough explosions, one-liners, chases and shootouts that we won’t notice.