‘Saw’ would work better if sharpened

You can always count on a serial killer for some memorable lessons in righteous living. No other type of cinematic villain is so didactic, so fundamentalist in his values, so committed to life coaching. It takes an intolerant ideologue with a black-and-white worldview and a superiority complex to make a moralistic slashegory work these days. In morally uncertain times, psycho always knows best.

The killer in “Saw,” directed by James Wan and co-written by Wan and Leigh Whannell, who also stars, does his best to fit in, but his anger feels inchoate, misdirected, sort of petty. The Jigsaw Killer, as he’s known, hates people who don’t fully appreciate life. So he plucks them from their routine, sticks them in a painstakingly engineered deathtrap and forces them to mutilate themselves or others to survive.

So far so good, as these things go, except that the Jigsaw Killer doesn’t seem outraged or repulsed by his victims -- a drug addict, a depressed guy, a guy who calls in sick too often -- so much as he seems annoyed by them. By the time he gets to the grumpy apathetic guy, you’re thinking the killer’s approach to victim selection is a little tetchy and scattered, as if he were drawing his righteous indignation from a Garfield desk calendar. He’s the Andy Rooney of serial killers.

Plus, his methods are undeniably grisly, but his concept isn’t quite nailed down. If there’s one thing we demand of a moralizing serial killer, it’s a certain pedagogic and aesthetic symmetry. But Wan and Whannell’s psycho suffers so much anxiety of influence (Dario Argento, David Lynch and David Fincher are quoted obsessively and indiscriminately) that his game is a hybrid mess. One minute, he’s locking victims into a Nine Inch Nails-inspired steel contraption; the next, he’s freaking them out with a Grand Guignol puppet on a tricycle and stalking around his lab in a Quasimodo cape. He’s a little bit Marilyn Manson, a little bit Vincent Price. Mostly, though, he’s incredibly industrious, especially in light of the final reveal.

The story begins as Adam (Whannell) wakes up in a filthy but spacious subterranean bathroom chained to some pipes, across from the similarly restrained Dr. Lawrence Gordon (Cary Elwes). Between them is a dead man (suicide) holding a gun in one hand and a tape recorder in the other. A couple of personalized tapes explain that whoever kills the other gets to live. As an added incentive, the voice on the tape throws Dr. Gordon’s family, unconvincingly played by Monica Potter and Makenzie Vega, into the mix. Also, a couple of saws too weak to cut through metal. Meanwhile, a freshly deranged detective named Tapp (Danny Glover) obsessively tries to crack the case, despite having been fired from the police department. Despite their deadline, Gordon fills Adam in about what’s been happening, which is how we learn that the doctor, the killer and the detective go way back, and how we come to suspect a certain sniffy, sexually ambiguous orderly, Zep (Michael Emerson), who arouses suspicion by being sniffy and sexually ambiguous.

“Saw” features some earnest scenery-chewing courtesy of Elwes, who has trouble holding on to his American accent as the stakes rise. (So does the Australian Whannell.) The paler and more frightened Elwes grows, the more he roars between whimpers, like he’s Richard III.

The scenery, as it happens, can’t really take the abuse. Oddly intent on coming across as ghoulish and macabre, “Saw” looks just like the starkly lighted B-movie set it is. It’s never a good sign when, as the hero’s wife and child are being tied to the bedroom set by the creepy orderly, one’s companion leans over and whispers, “I rented those bedposts from Universal once.” Generally, one prefers for the furniture to remain part of the furniture.

But “Saw” carelessly underscores its own shaky narrative at every turn with its mid-budget hokiness. This might be due, in part, to Wan and Whannell’s good luck. The two, who met as film students in their native Australia, are further proof that Hollywood dreams do come true -- as long as boys keep churning out gory, smart-alecky Fincher derivatives. The ensuing budget got them halfway to an expensive look. Not that this would’ve mattered had the story hung together. But “Saw” is so full of twists it ends up getting snarled. For all of his flashy engineering and inventive torture scenarios, the Jigsaw Killer comes across as an amateur. Hannibal Lecter would have him for lunch.

*

‘Saw’

MPAA rating: R for strong, grisly violence and language

Times guidelines: Gruesome violence inexplicably deemed as watchable as puppet sex

Cary Elwes...Dr. Lawrence Gordon

Danny Glover...Det. David Tapp

Monica Potter...Alison Gordon

Leigh Whannell...Adam

Makenzie Vega...Diana Gordon

Twisted Pictures present a Burg/Koules/Hoffman production, released by Lions Gate. Director James Wan. Producers Gregg Hoffman, Oren Koules, Mark Burg. Executive producers Stacey Testro, Peter Block, Jason Constantine. Story by James Wan and Leigh Whannell, screenplay by Leigh Whannell. Director of photography David A. Armstrong. Editor Kevin Greutert. Costume designer Jennifer Soulages. Music Charlie Clouser. Production designer Julie Berghoff. Art director Nanet Harty. Running time: 1 hour, 40 minutes.

In general release.