“Pinocchio” is an excuse for Roberto Benigni to gambol around like a ninny, acting merry and whimsical and annoying the hell out of everyone. It’s the way he behaved at the Oscars in 1999, when “Life Is Beautiful” was winning awards and he was America’s favorite irrepressible funnyman, climbing on seats and sloshing exuberance all over the theater. The difference between then and now? We weren’t tired of him then. Even by 2000, we were a little embarrassed we’d ever been so taken with the Italian goofball, and today, he is strictly on a case-by-case basis. We are keen to enjoy his movies when they are good — “Life Is Beautiful” is still a masterpiece, regardless of how Benigni acts in public — and to hate them when they are bad.

It is into the latter category that “Pinocchio” falls. It is a curiously mirthless, uninspired adaptation of the 1881 Carlo Collodi fairy tale, with 50-year-old Benigni as the title character.

Yes, it’s a little odd to have the famous puppet who wants to be a boy played by someone who already WAS a boy, and who stopped being one in the 1960s. The incongruity — nay, creepiness — of such an idea is one of the film’s numerous flaws.

Another one is the way it’s been dubbed. The English-language actors — Breckin Meyer, Glenn Close and John Cleese among them — are stuck reciting dialogue that sounds like it has been translated too literally. It is awkward and strange, in no way resembling the way people actually talk, or even the way movie characters actually talk. You can never get an emotional hold on the thing because you keep noticing how stilted the language is.

Much of it is obvious and redundant, too. Pinocchio has a habit of talking to himself, saying unnecessary things like, “I’m so scared! If I can get to that house, maybe I’ll be safe!” Well, duh.

The production and costume design, by Danilo Donati (his last work before dying in 2001) is splendid, charmingly setting the story in approximately the same era as when Collodi wrote it. But as a whole, the film is not fanciful enough to make us suspend our disbelief. Instead, we are nagged by questions: Why does everyone think Pinocchio is a puppet when he looks NOTHING LIKE A PUPPET? How does a boy sit in jail for four months without any attempt being made to contact his parents? Why is the owner of the puppet theater a giant? Why would Geppetto send his beloved boy off to school without an escort, or without at least giving him directions to the school?

Good special effects and Benigni’s flair for physical comedy are wasted in this insipid, nearly unbearable film. Take a step back, Roberto, and before you write, direct and star another film, get some input first. A fairy tale is a terrible thing to waste.

D (1 hr., 40 min.; G, nothing offensive, at least not from a moral standpoint.)