Like most origin stories, director Jon Favreau's film spends a lot of time before its superhero gets fully, recognizably superheroey, concentrating instead on the events that lead the title character—in this case boozy playboy weapons manufacturer Tony Stark—to begin fighting crime. While the long pauses between explosions might start the kids fidgeting in their seats, the buildup actually proves to be the most engaging part of the film, thanks to some unusually snappy patter and the toweringly charming central performance of Robert Downey Jr., whose improv rhythms and personal history combine to give his character's redemption unexpected weight. Good as he is, Downey is matched, and possibly surpassed, by Jeff Bridges's evil industrialist/father figure. Sporting a Cossack beard and an alarmingly un-Lebowski chrome dome, Bridges doesn't ditch his usual surfer demeanor, using it instead to mask a growing cutthroat malevolence. Whenever the two square off, the thing soars. Unfortunately, the action scenes lack the fizz of the character moments. Still, there's enough good stuff here to place this in the upper tier of movies about guys in long underwear. By Andrew Wright