In the movies, the old saying goes, some stars wear the hat. And sometimes, the hat wears them.

Say whatever else you want about Sylvester Stallone’s kitschy 1995 turn as futuristic comic book judge-jury-executioner Judge Dredd, the dude wore the helmet.

Karl Urban replaces him in the new “Dredd 3D.” And frankly, the helmet wears Karl.

He never takes off the over-sized thing. It closes off his performance and masks his charisma.

We only see his scowling jaw and hear his hissed one-liners, chewing out the rookie mind-reading judge (Olivia Thirlby) who forgets to wear hers.

“Sir, helmets interfere with my psychic abilities.”

“Think a bullet in the head might interfere with ‘em more,” the judge mutters.

In a future when much of America is irradiated and 800 million people are crammed into MegaCity, the concrete metropolis that stretches from Boston to Washington, tens of thousands are packed into mega high-rises, many at the mercy of mega criminals.

The judges are all that stand in the way of anarchy. They’re wired-in, hi-tech hunter/prosecutor/killers, men and women who solve (sort of) crimes, catch criminals and dole out punishment, on the spot.

The death penalty is their favorite.

There’s a new drug making the rounds. There always is. “Slo Mo,” it’s called, and Ma-Ma is the drug lord who has it. Lena Headey (“300”) plays her in a performance that begins and ends with the flashy scar-riddled makeup.

When Dredd and the “mutant” psychic judge-in-training, Anderson (Thirlby), nab one of Ma-Ma’s thugs (Wood Harris), of course you know this means war.

This “Dredd” is a limited vision of the future, mainly confined to one towering, rundown high-rise. Judge Dredd and Anderson and their prisoner must fight their way out of this building, which Ma-Ma’s minions have on lockdown.

This could have been claustrophobic, an action epic in compact form. “Die Hard” and last year’s Indo-Australian thriller “The Raid” are versions of this set-up that work.

With “Dredd 3D,” you get only a taste of that as the judges blaze their way through Ma-Ma’s murderers and supposedly innocent bystanders and await the back-up that seems awfully slow in coming.

The 3-D here is used to greatest effect in slow-motion shootings, impalings and throat slashings — blood-on-the-lens stuff.

The villain is poorly drawn. The script lets her down, and Headey just isn’t “big” enough, in persona, performance and presence, to suggest a murderous monster who ruthlessly slashed and intimidated her way to the top.

Thirlby is sensitive and cute as ever, funny when she has to be. She needs more to do.

And Urban — so droll as Dr. McCoy in the “Star Trek” reboot, so sinister as Black Hat in “Priest,” so worthy a foe for Bruce Willis in “Red” — is lost behind that big ol’ helmet.

That conspires to render the mega violent mega satire of MegaCity mega boring.

“Dredd 3D” (1/2 star)

Karl Urban can’t fill Sylvester Stallone’s helmet as he takes over the Judge Dredd role. The 3-D aspect is best during the gory shots, but the villaine is little more than scary makeup. With Olivia Thirlby, Lena Headey and Wood Harris.

Rated: R for strong bloody violence, language, drug use, sexual content.

Showing: Alderwood, Cinebarre, Everett Stadium, Galaxy Monroe, Marsyville, Oak Tree, Pacific Place, Woodinville, Cascade Mall.