Robert Redford and Debra Winger are both playing against their screen personas in "Legal Eagles," and together they work up a delightful brand of charisma. They don't boil, exactly -- their romance seems more like the fondness of an uncle for a favored niece -- but they do percolate, and their tender, jokey, low-key affection is what's best about the movie.

Lamentably, this chemistry is yoked to the tame and fairly transparent mechanics of a conventional whodunit. Redford plays Tom Logan, a divorced prosecutor who lives with his young daughter Jennifer (delightfully smart-mouthed Jennie Dundas); Winger is Laura Kelly, a defense attorney who'll try anything to get her criminal clients off the hook (we're told she once put a dog on the witness stand).

They get together when Chelsea Deardon (Daryl Hannah), a self-styled performance artist, is accused of trying to steal one of her father's paintings (a famous artist, he was killed in a fire). Laura is sure she's innocent. So she tries to enlist sk,2 sw,-2 ld,10 Tom in Chelsea's cause, asking him to drop the charges, and the good prosecutor, intrigued by both the dishy Chelsea and the adorable Laura, finds himself getting involved with arson, fraud, forgery, a mysterious detective named Cavanaugh (an unusually enervated Brian Dennehy) and a trail of bodies.

This formula, pairing murder with the life styles of the rich and famous, should be familiar to anyone who's ever watched "Columbo," which the story of "Legal Eagles" hardly exceeds in either invention or complexity. Director Ivan Reitman has advertised the movie as a stretch for him, a departure from his youth comedies, but it really isn't. "Ghostbusters" was rather more of an old-fashioned romantic comedy than some give it credit for, and "Legal Eagles," alas, is rather less of one than it seems.

Reitman's talent lies in his refined comic timing and an imaginative sense of farce staging, both of which are somewhat squandered on the "Legal Eagles" script. Screen writers Jim Cash and Jack Epps Jr. have gotten very hot in a short time (the summer's biggest hit, "Top Gun," is theirs, too), but it's hard to know why -- they build creaky machines that exploit old Hollywood genre movies without much wit or self-awareness.

So you watch Redford and Winger confront someone, discover a clue and then discover that someone is now dead; and again and again, you watch the ritual repeated. There's little in the story to hold your interest, and anyone who can't figure out the culprit probably hasn't seen many movies like "Legal Eagles."

But as a star vehicle, "Legal Eagles" is often engaging, mostly because of the stars who are vehicularized. Redford, with his golden good looks, has always made getting what he wanted seem as simple as a smile, so it's fun to see him as an amiable, somewhat befuddled klutz who loses his keys, takes guff from his boss and his ex-wife, and finds himself in a number of situations he can't find a way out of.

After all those strong-jawed leading man roles, Redford reveals himself to be a skilled comedian, a master of slow burns, double takes and Jack Benny pauses. And what makes the performance particularly pleasurable is that Redford seems to be as pleasantly surprised as we are. When Tom Logan can't believe the kind of comic messes he's gotten himself into, Redford can't seem to believe it, either. There's more joy in his work than there's been in years.

Redford's chief virtue as a film actor is his enormous relaxation (in movies like "Out of Africa," it can become a kind of torpor), and that's Winger's virtue, too -- she's never for a moment seemed anything but natural. In "Legal Eagles," she looks almost ordinary, pale without makeup, dressed in staid black and white, coifed like a schoolmarm. Like Redford, she's deliberately contradicting her screen image -- the actress who debuted in "Urban Cowboy" as a vessel of pure sexual heat has unsexed herself.

But that voice! Nothing could unsex that voice, all cracks and plaster and rough edges, a voice that often seems, no matter what dialogue shapes it, like a moan of pure pleasure. Hannah might appear on the screen with a slinky black gown and five yards of blond hair, but Winger's got her outgunned from the start -- she looks at Redford with her big blue beagle-eyes, and he doesn't know it yet, but he's gone.

At times, Redford and Winger are too relaxed -- you wish someone would light a fire under at least one of them, and you know it's not going to be Hannah, who's as inwardly brooding as she's ever been. And you wish that Elmer Bernstein's score was a little less fatuously bouncy, or that Laszlo Kovacs' cinematography were a bit less bleak, or that Redford had gone even further in his shenanigans.

But there are those other moments, too, when Reitman sets chaos loose, or Cash and Epps and their rewriters (notably, an uncredited Tom Mankiewicz) have turned a particularly funny line or bit of business, when you realize that "Legal Eagles" is as smart a comedy as any you're likely to see this summer.

Legal Eagles, opening today at area theaters, is rated PG and contains some mild violence, profanity and sexual themes.