Tony Stark, a most dissolute and disarming arms manufacturer, builds flamethrowers in the basement. For kicks. The bucks aren't bad, either.

Sporting wit (and goatee) sharp as a survival knife, Robert Downey Jr. is the billionaire bon vivant in Iron Man, the fast, funny and deliriously entertaining flick based on Marvel Comics' self-made superhero. Unlike genetic and environmental supers, this weapons whiz gives himself superpowers.

A hard-drinking inventor/playboy/businessman, Tony is a hybrid of Howard Hughes and Hugh Hefner, 1950s fantasy figures gene-spliced for 2008.

Tony sells bombshells to the Pentagon and procures them from the pages of Maxim. He lives in a Malibu villa with a panoramic view of the Pacific. His garage is stocked with hot cars, his bed with hotter women. On his private jet are flight attendants who do double duty as mile-high pole-dancers.

It would appear that there are no limits to the lifestyle of this smart-aleck designer of smart weapons. Yet, while demonstrating his company's newest missile, the Jericho, to U.S. forces in Afghanistan, Tony is ambushed by insurgents. To his horror, they hoard Stark Industries products and want him to build a Jericho to deploy against U.S. forces.

When Tony sees American soldiers killed by the weapons he designed to defend them, weapons that have left him with a heart full of shrapnel, he has a crisis of conscience.

With little more than a pile of scrap metal and a welding torch, Tony hammers out a masterwork of precision weaponry: an armored suit that enables him to elude captors and reinvent himself as a person concerned about the consequences of his weapons.

By a remarkably similar process in Iron Man, director Jon Favreau takes the scrap metal of the superhero scenario and welds it into new form, reinventing the oversimplified good-versus-evil genre to reflect on more-nuanced consequences of war.

Favreau, the off-center actor and director of Elf, Made and Zathura, is not the first guy you'd think of for this assignment. And thank goodness.

Like Johnny Depp as Jack Sparrow, Favreau's casting of the sardonic Downey as Tony Stark is a risk that pays off. Downey is a gifted actor who suggests two moods at once, flippantly tossing off serious commentary, embedding the debate about war into his character. Though neutral about current events in Afghanistan and Iraq, the film is militantly anti-war profiteer.

Favreau elicits more emotional tonalities from his actors than ordinarily found in a film based on a comic book. Aside from Downey, the film boasts Jeff Bridges as Tony's charismatic and cagy business partner, Obadiah; Gwyneth Paltrow as Tony's smoothly sarcastic assistant, Pepper; and Shaun Toub as Yinsen, an Afghan doctor whose surgical skills and gallows humor save Tony's life.

As great as Downey is and as entertaining as the other performances are, what makes the film is Tony's joy of making. Whether Tony is in an Afghan cave, his ailing heart hooked up to an electromagnet and a car battery while improvising his first armored suit, or in his basement, designing and test-driving Iron Man's gold-and-titanium upgrade, the film delights in the mechanics of invention, which is infectious. It's a machine dream, and a happy relief from the typical blockbuster's reliance on digital effects.

(One of Tony's inventions, a surveillance device that identifies civilians and targets terrorists, would be extremely useful.)

Until a final conflict that more resembles a monster-truck jam than a superhero showdown, Iron Man is solid gold.

Contact movie critic Carrie Rickey at 215-854-5402 or crickey@phillynews.com.
Read her blog, "Flickgrrl," at http://go.philly.com/flickgrrl/