As noted in This Is Spinal Tap, there’s a fine line between stupid and clever. If the original Dumb and Dumber was clever, this prequel falls squarely on the stupid side. Although the Farrelly brothers aren’t on board, the director and co-writer is Troy Miller, a veteran of the great sketch-comedy program Mr. Show; and it’s uncanny how much the film’s stars, Eric Christian Olsen and Derek Richardson, at least look like younger versions of Jim Carrey and Jeff Daniels. But in the original, our two lovable dunces, Lloyd and Harry, were funny because, empty-headed as they were, they handled life in an oddly logical way. Plus, there was Jim Carrey. But with no cleverness in the script or the characters, Dumb and Dumberer is doomed to fail. Harry and Lloyd are put in a special-needs class that their high-school principal (Eugene Levy) has put together with "regular" kids so that he can receive — and abscond with — special grant money. The thing is, Harry and Lloyd are so "dumb" here that they should be in a legitimate special-needs class. What’s funny about that? (85 minutes)