One hesitates to be too hard on a creative team that’s provided many hours of great entertainment—not just great family entertainment, but simply great entertainment—over the years, but Pixar seems to have fallen into something of a funk. “Up” was the animation outfit’s last real masterwork, and though the featurette “The Blue Umbrella,” which is being shown before “Monster University,” shows the quality of which they’re still capable, the movie that it accompanies is just a pleasant but minor diversion, not up to the standards one used to expect from Pixar.

The problem is one that blights all of Hollywood—the repetition that comes with sequels. “Toy Story 2” was a deserved smash, but its success spawned “Cars 2,” which might well have been the worst Pixar movie yet. And while 2001’s “Monsters, Inc.” was good enough, the idea of doing a prequel—which is, after all, no better than a sequel—evinced a paucity of imagination, and the outcome bears that out. “Monsters University” is hardly as bad as “Cars 2,” but it’s pretty ordinary, even compared to its modest predecessor.

The premise is that eager little one-eyed Mike Wazowski (Billy Crystal) and gruffly likable aquamarine giant Sulley (John Goodman), the monster partners of the first movie, met as incoming freshman in the Scare section of the titular M.U. and immediately rubbed one another the wrong way, Mike being the unthreatening twerp who depends on book learning to graduate and Sully the big, frightening guy from a famous family who thinks he’s a shoo-in without studying. But after both alienate stern Dean Hardscrabble (Helen Mirren) and face expulsion, their only hope of survival is to win a Scare Contest. That requires them to be part of a fraternity team, however, and the only one with openings—needless to say—is the bunch of lowly misfits of Oozma Kappa, who become their “brothers.” The four goof-ups they find themselves partnered with in the crazy Olympics are plump, naïve Squishy (Peter Sohn), maniacal puff-ball Art (Charlie Day), quarrelsome brothers Terri and Terry (Sean Haynes and Dave Foley), who happen to share a two-headed body, and avuncular retiree Don Carlton (Joel Murray). Mike and Sully join them in the frat house that’s actually Squishy’s family home, complete with his equally plump and endlessly spunky mom (Julia Sweeney) as den mother.

Much of the rest of the picture is devoted to the different challenges the OK guys have to face against teams from the other Greek houses, most notably the dominant one—ROR—headed by arrogant (and literally bullish) bully Johnny Worthington (Nathan Fillion). And even after they win—a spoiler that will come as no shock to anyone—their victory isn’t the end of things, and it takes a visit to the terrifying human world to prove that together they’ve got the right stuff, even if—as a credits summing-up shows—it will take a long climb up the ladder before they ultimately earn their scare stripes.

This is amiable stuff with a predictably benign message that comes down to not judging books by their covers. And Mike and Sulley remain genially engaging characters whose interaction provides contented smiles. The new supporting characters are generally agreeable too, with Mirren making a formidable impression and the rest having their moments—though better use could certainly have been made of Steve Buscemi as Mike’s roommate, a lizard with the ability to go invisible. And the animation is as top-of-the-line as one would expect.

But most of the really laugh-out-loud moments in “Monsters University” don’t come from the main characters at all; they arise from throw-away bits like a gag about a slug (or is it a snail?) desperately trying to get to class on time, and they last but an instant before the movie has to get back to churning out plot. There’s also a problem in the lack of a truly compelling villain. Hardscrabble is a tough cookie, no doubt, but she’s not really villainous, and Fillion’s Worthington is a standard-issue BMOC type.

One’s left with likable but fundamentally ordinary 3D-animated children’s fare, which in the Pixar canon doesn’t represent so much a return to form as a continuation of decline.