The action romp “The Lost City” is an inferior version of almost every single adventure comedy it steals from. But that’s the joke here, and it plays. Because there’s a lot of stealing going on in this multi-hand script, all-star cast spectacle.

The obvious inspirations are the “Romancing the Stone” movies, with a romance novelist — Sandra Bullock here, Kathleen Turner way back when — kidnapped into a daft adventure of the sort she usually writes about. But there’s a hint of “Nim’s Island,” too. Our novelist has become something of a recluse, and the guy who sets out to rescue her is her fictional action hero, Dash. Only “Dash” in this case is the “Fabio-wigged” model for the covers of her books. Alan poses as Dash on her covers, and hapless, handsome language-mangling hunk Alan is played by the generally shirtless Channing Tatum.

There’s a rich supervillain, as there always is, and if Daniel Radcliffe‘s name isn’t the first you think of when that character is labeled, it will after this. Radcliffe co-starred in “Jungle,” a movie about searching the jungle for “lost villages,” which doesn’t feel like a coincidence.

Because Brad Pitt, in a scene-stealing first act cameo, once produced and gave some thought to starring in “The Lost City of Z,” a true story about the search for an ancient city lost in the jungles of Amazonia.

Even the casting takes on a jokey air in “Lost City,” with moments meant to mimic “Raiders of the Lost Ark” and every other movie with a modern setting and a “lost treasure” in the tropics as its “MacGuffin.” Hell, there’re even jokes about Fabio and MacGuffins in this tossed salad of a screenplay.

Bullock is Loretta Sage, who “used to be the best selling” author of her romance genre, something her agent (Da’Vine Joy Randolph) is gambling a lot of cash on as she talks the now-widowed and reclusive author out of seclusion and onto a book tour.

Booking Loretta with the vapid and insanely popular cover model (Tatum) of her books for joint appearances is the first sign that this is going to be a nightmare. There is no metaphor this himbo can’t mix, no semantic stumble he can’t manage. She’d much rather be done with the books and him so that he can set off on “The shirts-on phase of your career.”

Then she’s kidnapped after a book signing. It turns out, those quest romance novels were written by a trained historian and ancient languages linguist whose late husband was an archeologist who did some poking around looking for the Lost City of D. And that’s what billionaire punk Abigail Fairfax (Radcliffe) wants to find. Yes, there are jokes about wealthy Brits giving their sons effeminate names.

Loretta’s barely yelped, “What IS this, ‘Taken?'” when Alan — who hears the phrase “You DO realize you’re NOT Dash?’ more than once — springs into action. There was this special ops/soldier of fortune dude he met at some meditation retreat/whole-body-cleanse/ashram whatever.

You can tell on the phone that Jack Trainor is Mr. No-Nonsense, Mr. Competent, Mr. “Proof of Life” Rescuer. You can tell on the phone that Jack Trainor is played by Mr. Brad Pitt. And he’s hilarious.

That’s the first big joke that works, and his few scenes get “The Lost City” on its feet, onto the island where Loretta’s been taken to decipher ancient writings and locate this buried “Crown of Fire,” and into comic mayhem as prissy, pretty and dim-witted Alan becomes her last, best hope of getting out of this alive.

Bullock had a gift for Lucille Ball pratfalls in her early comic career, and she does a fair job of reviving that shtick here, traipsing and tripping through jungles in a “SeaQuest” pink sequined jumpsuit, chased by goons on motorcycles and a supervillain in his own luxury tank.

There’s a clumsiness and tendency to miscalculate by every character in this — from the villain who doesn’t realize what his vertical take-off jet will do when its engines focus on a nice cheese sampler smorgasbord he’s laid out for his “guest,” to the “rescuer” who seems to mainly want credit for trying to “save” his meal ticket, to the writer herself, who is forever judging “a book by its cover.”

Only Pitt’s Trainor, running up trees, dispatching one kidnapper after another, tracking and plucking a plainly smitten Loretta in a flash, knows what he’s doing here. And what do we do with “competence” in America, kids?

“Lost City” works up a head of steam, but only here and there. Bullock is amusing and effective as the lead, although you have to believe she’d have thrown herself into this with real abandon 20 years ago. Tatum, Radcliffe and Pitt have their moments.

And “Office” alumna Oscar Nuñez makes a delightful appearance as a low-rent local cargo pilot who takes a fancy to Randolph’s irritated and on-task agent.

But there are characters who don’t land all the laughs they should and more than one situation whose clunky payoff slows the picture’s joke-to-joke rhythm and pacing.

Nobody could confuse the co-directing Nee Brothers (“Band of Robbers”) for comedy auteurs, although to be fair, this script feels more cut-and-paste than inspired.

The fact that “Lost City” still plays, still delivers plenty of cute and sometimes bawdy laughs amidst all the homages and “borrowings” from better films is a tribute to its stars and its one great conceit — that it’s taking on a jokey, derivative genre, and everybody we see in it is in on that joke.

Rating: PG-13 for violence and some bloody images, suggestive material, partial nudity and language.

Cast: Sandra Bullock, Channing Tatum, Daniel Radcliffe, Da’Vine Joy Randolph, Oscar Nuñez and Brad Pitt.

Credits: Directed by Aaron Nee and Adam Nee, scripted by Oren Uzeil, Dana Fox and Adam Nee. A Paramount release.

Running time: 1:52