Harmless as a puppy, “Bolt” comes bounding into theaters, stumbling over its big, goofy paws, wagging its fluffy tail and begging to play ball.

It’s sweet and eager to please but, sadly, nothing terribly special: Girl finds dog, girl loses dog, girl gets dog back. You’ve seen this sort of thing countless times before, namely in any movie with the word “Lassie” in the title.

But if you happen to be a girl who loves dogs, you may find yourself wiping away a tear or two.

This animated 3-D adventure follows a scrappy, white shelter mutt named Bolt (voiced by John Travolta) who isn’t a superhero, but he plays one on TV. Trouble is, he has no idea he’s an actor in a role. He thinks he’s really saving plucky, young Penny (Miley Cyrus) — his “person,” as he’s so proud to call her — from bad guys and explosions over and over again.

When Bolt accidentally gets shipped across the country from Hollywood to New York City, in a totally contrived fashion, he must make that tried-and-true, intrepid trek back home. Travolta, so often pigeonholed as a tough guy or an idiot or both, shows some lovely glimmers of vulnerability here, especially once he realizes he’s just a normal dog after all.

Along the way, he befriends the street-wise, wisecracking alley cat, Mittens (Susie Essman in a slightly less vulgar mode than you’d find her on “Curb Your Enthusiasm”), and the overeager, overfed hamster Rhino (the scene-stealing Mark Walton), who’s obsessed with television and is totally psyched about the prospect of being Bolt’s crime-fighting sidekick. A sort of small, furry Louie Anderson look-alike, the delusional hamster is an undeniable hoot but “Bolt” goes to him a few times too many for the reliable laugh; a little of Rhino goes a long way.

“Bolt” is the first animated feature created and executed under longtime Pixar guru John Lasseter, but it lacks the complexity of story and depth of character you so often find in previous Pixar releases such as “Toy Story,” “Monsters Inc.,” “The Incredibles” and this year’s outstanding “WALL-E.” The film is familiar rather than groundbreaking, safe when it should be moving. Call it an occupational hazard: Lasseter is too good at what he does; it’s not a terrible problem to have.

As for the 3-D, it will suffice. “Bolt” could have survived without it and still have been as diverting. Thankfully, it doesn’t fling anything at you gratuitously, nor does it envelop you wholly. Rather, with the help of some inordinately sturdy dark glasses, the 3-D effect provides “Bolt” with a pleasing sense of texture, an effortless tangibility in the blades of grass or the hair on the back of the lost pup’s neck.

Meanwhile, Bolt has been trying to navigate the perils of the real world with no superpowers: “If I stare at the lock really hard, it’ll burst into flames and melt,” he insists with total earnestness. No such luck.

He does, however, run into a trio of pigeons who have a script to pitch once he makes it back to L.A. So maybe “Bolt” is a documentary after all.