Ben Wheatley went high-concept in his adaptation of J.G. Ballard’s High-Rise, following the residents of an all-inclusive luxury building who turn to literal class warfare when the structure’s essential systems break down.

Having excelled at conveying those heady themes, he and spouse Amy Jump – the writer and co-editor on each of his films – toss intellectualism aside in favor of pure entertainment in the joy ride known as Free Fire.

The duo recycle High-Rise’s ‘70s setting and fashion, if not some of the same exact wardrobe pieces, for their look at IRA arms buyer Chris (Cillian Murphy) aiming to outfit his countrymen in a hurry.

Flanked by confederate Frank (Michael Smiley), himself bringing junkie brother-in-law Stevo (Sam Riley) and his dimwit friend Bernie (Enzo Cilenti) as questionable muscle, they’re led by American conduits Justine (Brie Larson) and Ord (Armie Hammer) into an abandoned Boston warehouse. 

Awaiting them are South African gun runner and, in Justine’s words, “international asshole” Vern (Sharlto Copley) and his Black Panther reject partner Martin (Babou Ceesay). The gang all there and cheeky insults equally distributed, the hosts call over associates Gordon (an underused Noah Taylor) and Harry (Jack Reynor) in their loaded van, whose speakers blast the ultimate criminal anthem: John Denver’s “Annie’s Song.”

Tensions go from simmering to a medium boil when Vern pulls out firearms that, while acceptable, aren’t what Chris requested. But with the deal nonetheless ready to go down, two rival parties recognize one another, shots are fired and everyone scrambles behind whatever debris they can find.

Its handle on comedy well established within the first few minutes, Free Fire comfortably folds in its action component, keeping the jokes coming as fast as the bullets, and all the better when they’re in tandem.

Copley detractors – and there are inexplicably many – are dared not to fall for his Vern, but while his nutty one-liners make him the shootout’s class clown, everyone capitalizes on his or her chance to earn a laugh.

For all the thrills the action and comedy deliver, plus the jolts of some creative, gruesome deaths, there’s an occasional sense of monotony to Free Fire’s soundtrack of loud gunshots.

And while it’s often difficult to get a grasp on the warehouse layout or where everyone is, that apparent shortcoming matches the disorientation of the players themselves. The confusion also keeps one guessing about certain character loyalties, answers to which aren’t reached by taking easy routes that lesser films would certainly blaze.

If these accomplishments weren’t enough, the film has the gift of brevity on its side as well. At one point, Ord refers to the “golden hour and a half” between getting shot and needing medical attention – and it’s therefore only fitting that Free Fire clocks in at a lean 90 minutes, achieving maximum effect over that span and serving notice to its bloated peers that they can and should do better.

Grade: A-minus. Rated R. Now playing at Carolina Cinemark and Grail Moviehouse

(Photo: A24)