“One day, Mikey, you’re going to stick your dick in the wrong door and somebody’s going to slam it.”

So reads the puzzlingly serious script for “Man On A Ledge,” a film so absurdly unaware of its own ridiculousness that it borders on being an unintentional masterpiece. Unfortunately, director Asger Leth’s debut thriller isn’t enjoyable enough to hit that mark, leaving us with a film that can only be described as one part drinking-game funny and two parts maddeningly inept.

The premise is interesting enough: Nick Cassidy (Sam Worthington, sporting an accent that fluctuates comically from shot to shot) is a fugitive on the run, wrongfully accused of stealing a precious diamond from an evil rich guy (Ed Harris). Desperate to prove his innocence, he climbs onto — you guessed it — a ledge, grabbing the attention of the media and effectively distracting the police while his brother steals the real diamond from the rich guy’s building. Elizabeth Banks plays the uncharacteristically hot negotiator appointed to talk him down, a task she’ll only accomplish if she can figure out his true motive and help him clear his name.

Sounds fun, right? Well, it would be, if the film had any clue what kind of tone it was going for.

Instead, “Man On A Ledge” runs like a bad joke, playing things serious when they’re obviously absurd and shooting for laughs when the narrative clearly calls for suspense. The result is a very boring film, lifelessly performed and laugh-out-loud funny in every place it doesn’t mean to be. Take, for instance, the heist itself: Cassidy’s brother and his brother’s girlfriend, neither of whom has ever done anything illegal, break into the rich tycoon’s building carrying fire extinguishers, explosives, wet suits, bedsheets, a skateboard, 10 or so digital cameras, an infrared fingerprint monitor and a coffee thermos filled with liquid nitrogen. And all of this, mind you, they’ve fit into two regular-sized backpacks.

I’m sorry, but … what?

The problem, of course, is that all of this is played with stone-faced seriousness. Worthington and Banks scowl at each other amid lengthy exposition (“You’re Lydia Mercer, the woman who failed to stop a guy from jumping off the Brooklyn Bridge and now has an alcohol problem because blah blah blah blah”), while the rest of the characters run around panicking about vague emergencies that for whatever reason are left entirely unexplained.

Had “Man On A Ledge” opted to acknowledge its silliness from the start, the plot’s inevitable spiral out of the logical stratosphere would be far less painful to watch. But by the time the “twist” ending was revealed, the groans in my theater were echoing out of the building and across the street.

All in all, this isn’t a malicious film, just a confused one. As far as drinking-game movies go, it might not be as effective as, let’s say, last year’s “Green Lantern,” but it’s definitely the most unintentionally funny film of 2012 so far. Whether or not that’s a good thing will be up to whoever sees it.