Those worried about what Joss Whedon, the creator of “Buffy” and “Firefly” and director of “The Avengers,” might do with (or to) Shakespeare’s “Much Ado About Nothing” can rest easy. There’s not a vampire slayer, spaceship captain or masked superhero anywhere in sight in his film of the play, though actors who have performed in the director’s earlier films in those genres are on hand. What there is, however, is a good deal of charm, effervescence and rollicking humor—as well as attention to the more serious romantic undertones of the work. This is a surprisingly clear-headed and faithful adaptation.

Whedon shot the picture in less than two weeks at his own Los Angeles home, with a cast familiar from their appearances in his other projects. At the center is Alexis Denisof as Benedick, the smug, cynical soldier who spars combatively with Amy Acker’s tart-tongued, shrewish Beatrice until, as a result of the machinations of his general Don Pedro (Reed Diamond) and his co-conspirators, including Beatrice’s uncle Leonato (Clark Gregg), both of them come to realize that the contempt they spew at one another is actually just disguised love. Their story is juxtaposed and contrasted with the romance of Beatrice’s young cousin Hero (Jillian Morgese) and Benedick’s comrade-in-arms Claudio (Fran Kranz), which Don Pedro’s villainous brother Don John (Sean Maher) and his underlings Borachio (Spencer Treat Clark) and Conrade (Riki Lindhorne) attempt to undermine by falsely besmirching the girl’s reputation, much to the distress of her father, who is hosting the entire retinue. It takes one of the Bard’s audacious impostures, this one involving a false funeral, as well as the intervention of the bumbling policeman Dogberry (Nathan Fillion) and his goofy deputies, to set things right.

Whedon has tweaked the Shakespearean text, but not severely: the wit and dash—as well as the darkness of the Hero-Claudio subplot—are maintained. And he’s managed to present it in a fashion that modern viewers can enjoy without feeling that they’re experiencing a museum piece. Basically he’s embraced an approach reminiscent of classic Hollywood romantic comedy—screwball comedy in particular—with dialogue delivered swiftly and emphatically and the action choreographed to walk a fine line between broad slapstick and arch sophistication and only occasionally slipping. The luminous black-and-white cinematography of Jay Hunter also accentuates the connection with the great, smart film comedies of the thirties and forties.

Of course, nothing would work without a cast that was comfortable with the text and one another. Acker and Denisof spar with abandon but retain their humanity in the process, and though Morghese and Kranz have the less virtuosic parts, they also bring a sense of reality to them. Diamond and Gregg lead the way in the supporting cast, the former investing Don Pedro with authority and the latter giving Lotario a sense of decency and vulnerability. But special praise must go to Fillion. Dogberry—the focus of the typically brash farce that Shakespeare always directed to the groundlings—is often the bane of the play, a tiresome braggart. With Whedon’s complicity, Fillion underplays him, coming across like a cop on a TV show who’s just at the edge of retirement and anxious to get away from his obtuse subordinates. It’s a take on the character that actually makes a part of the play that rarely works genuinely funny.

Kenneth Branagh, of course, made a film of “Much Ado About Nothing” in the early nineties, and it’s a good traditional take on the piece. But this one, though done in modern dress at a very contemporary house, is more imaginative and appealing, and may actually capture the spirit of the play more successfully. And if it draws in some of Whedon’s fans and gives them a taste of something very different from “The Avengers” and “Buffy,” more power to it.