Surrogates mostly forgoes bombastic action for a shrewdly cautionary tale with a breathless smart sci-fi rush and great work from Bruce Willis. It’s an efficient, engaging B-movie parable that grapples with technology, civil liberties, terrorism, freewill and religious subtext all in 89 minutes.

Adapted in zippy format from Robert Venditti and Brett Weldele’s graphic novel, Surrogates is a smarter spin on the core idea of I, Robot and a true rarity: a good movie in which bald Bruce Willis boasts a full head of hair.

Maybe it’s only because Willis’s Young Republicans swoop — which makes him look like a human version of a youthful Homer Simpson — only shows up half the time and is knowingly fake per the narrative. That’s because the crummy haircut is plastered atop the surrogate self of Willis’ character, FBI Agent Tom Greer.

Greer is one of billions worldwide who regularly uses a surrogate — a walking, talking robotic representation of a human. Created as a medical breakthrough, surrogacy has now made its way to the leisure market and is affordable to everyone.

Operating these surrogates are people plugged into “stem” chairs and able to vicariously experience life without leaving their house or fear of bodily harm. The surrogates are, invariably, beautiful facsimiles of people whose hair has long since fallen out, whose psyches have shattered and whose skin has gone mottled. (Plus, as in the somewhat similar Gamer, a fat man operates a buxom woman.)

There’s an appreciable sterility to the surrogates and their surroundings, as realized by director Jonathan Mostow (Terminator 3: Rise of the Machines) and a crack visual-effects crew.

Everyone’s synthetic self looks smoothed over and expressionless, with enough digital smudges to sell the fakery, but not so unrealistic as to be off-putting. And the film looks somewhat sound-stagey — like a 1989 Touchstone movie, not a 2009 one — and yet it feels like intentional milieu, not cheapness of budget.

In this world, crime drops by 99 percent. Racism and sexism are eliminated. Everyone, seemingly, is better off through a combination of separation and sedation.

However, youth and attractiveness are traded like fast-moving commodities. Society’s senses are over-stimulated to a point where it takes “jacking” — a drug-like jolt of electricity to a surrogate — to elicit joy. And surrogacy’s prevalence has spawned a Luddite revolution, led by the dreadlocked Zaire Powell (Ving Rhames).

And it’s about to get stressful for Greer and his partner, Peters (Radha Mitchell), with the murder of Lionel Canter Jr. (James Francis Ginty) — son to the reclusive father of surrogacy (James Cromwell). The son died from a blast from a pulse gun somehow able to both destroy surrogates and liquefy the brains of humans operating them.

To prevent a public panic — and find the murderer — Greer and Peters’ investigation takes them deep into the Human Project. Eventually, Greer will have to shed his shiny surrogate skin and dangerously trek the real world for the first time in years.

Mostow plays up the Kurt Vonnegut-ian aspects as much as an $80-million movie will let him. Though the film has a hard-charging barrel roll momentum, Mostow settles for two good action sequences rather than a slam-bang pace.

Instead, he and screenwriters John Brancato and Michael Ferris (T3 and Terminator: Salvation) are more concerned with paralleling this world to ours. Surrogates allows frightening notions to fester, with undercurrents of the Patriot Act, judgmental acts of godliness and the idea we’re together, but alone, tied into virtual selves. Tamer than Gamer, but no less effective, it sells the sedentary pox surrogacy has become.

Potent, too, is Willis’ work as the real Greer — pockmarked, bearded, unkempt and getting the stuffing beaten out of him, much like the Bruce Willis we often see onscreen.

He longs to truly reconcile with his wife, Maggie (Rosamund Pike). She uses her surrogate as a pharmacological aid to block out the death of their son. In one seemingly insignificant scene, Willis sells the physical sense of touch and Greer’s emotional longing with just a glance.

Haunting, too, is a scene, when Greer violently rages against a machine and learns the futility of human aggression in such an emotionally stunted society. Mostow also lingers deeply on all the cuts and contusions the real Greer suffers in a world that now seems so loud and zoological to him.

It adds up to incredibly tactile filmmaking from a project that looked only to have the slick sheen of sci-fi going for it. Instead, it’s a taut and cautionary, if palatable for the mainstream, tale against numbing ourselves at the root of reality.