There are no new tricks in “Old Dogs,” and the old ones are badly played. This is a lowest-common-denomination comedy reminiscent of the worst movies the late John Hughes made as his career was winding down.

The premise—which stretches back to TV’s “Bachelor Father” and much further into the past—is that Dan (Robin Williams), a middle-aged guy who’s always been unlucky in marriage learns from his ex-wife Vicki (Kelly Preston) that his has two kids he didn’t know about, twins Emily (Ella Bleu Travolta) and Zach (Conner Rayburn). Not only that, but since she’s going into jail for a brief stint and Dan injures the woman who’s going to take the urchins in while their mother’s incarcerated, their new-found daddy is suddenly elected to serve as their babysitter.

But since he lives in an adults-only condo, Dan convinces his best buddy Charlie (John Travolta), a glad-handing womanizer who’s also his long-time business partner in a sports management firm, to let them all stay with him.

That occasions a slew of supposedly funny but actually painfully limp slapstick episodes as the boys try to deal with the kids while putting the finishing touches to their biggest deal in thirty years, a contract to represent a Japanese firm; these alternate with others of sloppy sentimentality as dad and kiddies bond. The laughs usually depend on one or another of the stars getting humiliated in some fashion, and it’s difficult to decide which of the sequences is worse than another. Perhaps it’s the crude, violent sequence involving a camping session that features Matt Dillon doing some of the lamest shtick in the movie. Or the one in which Williams is decked out in a “human puppet” gadget devised by a showman named Jimmy Lunchbox (Bernie Mac). Or the golf game in which Williams is suffering from taking the wrong pills—that distort his depth perception—and hits balls into everybody’s crotch. (Travolta, also affected, merely has to slather food over his face and wear a hideous “Mr. Sardonicus” sort of grin.) Or the culminating sequence in which they, along with their goofy young cohort Ralph played by Seth Green, are trapped in a zoo’s gorilla enclosure (cue the guy in a bad costume), which is followed by an equally crummy finale in which Williams rides a mini-helicopter to impress his kids.

This exhibition of puerile humor, with lots of jokes about “poop” both human and animal, and way too much footage of the hirsute Mr. Williams in various states of undress, is delivered without a scintilla of style and even less wit. It also contains a greater percentage of that bane of bad comedies—reaction shots from a dog—than any other movie I can remember. (That mutt eventually even gets a funeral, complete with a framed portrait of the deceased.) The overuse is a sign of the lax direction by Walt Becker (“Wild Hogs”), who’s entirely too permissive with the cast, letting everybody mug ferociously, especially his stars. And technically the picture is mediocre, often looking positively ugly. It also features one of those dreary comedy scores (by John Debney) that tries desperately to punch up every lousy gag.

“Old Dogs” must have been sitting on the shelf for a while—the presence of Mac in the cast, who died some time ago, is proof enough of that—but the aging process certainly hasn’t improved it any. When Williams apologizes to his daughter for one of his many mistakes by saying that it was “like trying without succeeding,” he might be describing the whole sorry mess. This is a mangy, flea-bitten comedy of “Daddy Day Care” caliber.