It’s always looks so easy in the movies, “the Big Score,” the “heist.”

“Oceans 11,” Oceans 12,” “Oceans 13,” “Oceans 8” or even the woebegone “Logan Lucky” go off like clockwork. The “team” of smart, smooth career criminals with “special skills,” is assembled, the “joint” is “cased,” the caper is rehearsed — preferably with a scale model of the “mark” in question.

The crooks, who banter and get along — when they aren’t double-crossing each other — have seemingly unlimited resources, especially in the glossy all-star caper comedies of Steven Soderbergh.

But the truth is a lot more like “Masterminds,” disorganized mayhem masterminded by morons, or at least people who don’t know what they’re doing. Because they taught themselves how via the movies.

“American Animals” makes it look hard. British producer-director Bart Layton, of TV’s “Breakout” and “Locked-up Abroad,” uses that access to real criminals to conjure up a near masterpiece of  “just ordinary guys out to commit a robbery” genre.

It’s a suspenseful “How to” primer and a droll, amusing and sobering “How NOT to,” the sort of movie that could discourage all the bumpkins, frat boys and anybody else bellowing, “WE could do that” while watching a heist picture and knocking back a few.

The Lexington, Kentucky quartet who actually took their shot at instance riches over a dozen years ago could have used that.

Yes, many of us might be able to score a fake-ID. Anybody with a zest for playing dress-up could figure out a disguise. Procuring firearms? This is America. “Whatever you want.”

But surveillance of the place you want to rob without being detected, “logistics,” how to get in and out, procuring a get-away car, finding a “fence” to sell the stolen property to, hurting somebody who gets in your way? That’s where the fantasy sets in. That’s where the “American Animals” get in over their heads.

Barry Keoghan (“Dunkirk”) is Spencer Reinhard, a UK frat boy studying art who takes a shine to the rarer-than-rare, oversized and illustrated by the author John James Audubon “Birds of America” stored under lock-and-key at nearby Transylvania University.

An introvert like Spencer would never act on any thieving impulse. Or so he’d have us believe. So his reprobate adrenaline junky pal Warren (Evan Peters, Quicksilver in the “X-Men” movies) is who he decides to tell about it.

And Warren, jock that he is, takes the ball and runs with it, right up to the moment he sizes up the task and cracks, “We’re going to need a bigger boat.” They need a larger crew. Smart, organized Eric (Jared Abramson) and go-getter/overachieving, monied entrepreneur “Chaz” (Blake Jenner) answer the cryptic question, “Are you out or are you IN?” in the affirmative.

Are they there for the cash? They’re all middle class to upper middle class “kids.” Curiosity of the “What would actually happen in REAL life” variety? Thrill criminals of the Leopold & Loeb persuasion?

Or was it just testosterone-fueled peer pressure?

Layton zips through the obligatory preliminaries — getting a laugh out of the “scale model” cliche, letting us see the various holes in their “fool-proof plan,” as in, a plan conceived by fools who rent “Heist” and “The Thomas Crown Affair,” who watch Sterling Hayden tough-talk the gang through “the plan” in the Kubrick classic, “The Killing,” by way of preparation.

They take on “color” names, just as in Tarantino’s “Reservoir Dogs.”

“Can I just say how DUMB this whole thing is?”

“This is just how it’s done,” Warren brags. Like he knows.

But Layton, with all his access to reality TV convicts, lifts “American Animals” to another level by the simplest device imaginable. He has the real crooks comment on their actions, thoughts at the time, and their remorse. He interviews the family, teachers and others about how “We were in SHOCK” at what these boys did.

And from time to time, he injects the real Spencer, Warren, Eric and Chaz, into the action, staring in forlorn regret from a driveway as the fictional versions of themselves drive the getaway car towards their “destiny,” and actually IN that car, stupefied at what their younger self just did.

It’s clever to the point of bloody brilliant, and you can say that about the entire movie as well. Peters pegs the needle as a hyped-up punk in need of a thrill, Keoghan (also seen in “The Sacrificial Deer”) makes you wonder if cagey introvert Spencer’s version of events is true, or a cover-up.

Ann Dowd is the officious, grandmotherly librarian in charge of “special collections,” the one they know they have to “eliminate.” And Udo Kier is all understated menace as a Dutch fence, the one person they can find who might buy what they steal, if they can steal it.

“American Animals” is a tense, taut sober and occasionally silly thriller that reminds us that the Caribbean Island at the end of the Hollywood heist is always a mirage. Real life is not like a Steven Soderbergh movie, and real crooks aren’t all-knowing versions of Bullock, Clooney, Pitt and Cheadle.

They make mistakes, even the ones who aren’t American idiots.

MPAA Rating: R for language throughout, some drug use and brief crude/sexual material

Cast: Barry Keoghan, Evan Peters, Blake Jenner, Ann Dowd, Jared Abramson, Udo Kier

Credits: Written and directed by Bart Layton. An Orchard release.

Running time: 1:56