Faithful readers of this space know how I feel about the Dopey Daddy stereotype that stumbles its way through commercials, sitcoms, and movies like ''Cheaper by the Dozen." Life isn't hard enough for us guys without this pernicious cliche coming in for ritual humiliation from the media? Does Hollywood think we enjoy being painted as clueless mouth-breathers mocked by sassy, knowing wives and painfully hip kids? Where's the respect? Where's the love? It's as big a mystery as where the moms go in Disney cartoons.
In ''RV," the broad-as-a-mobile-home new comedy from, of all people, Barry Sonnenfeld (''Men in Black," ''Get Shorty"), Robin Williams gives us a Dopey Dad for the ages. His character, a corporate executive and suburban father named Bob Munro, lies to his family, grovels, whines, sputters, shrieks, sweats, and purses his lips in that familiar expression of Williams Agonistes. His blue eyes water with the pain of castration administered on a daily basis. Is Bob mourning his trapped life or Williams his stalled career? Whatever, the performance might be art if the movie weren't such by-the-numbers offal.
The Munros -- Bob, wife Jamie (Cheryl Hines of ''Curb Your Enthusiasm," snotty/trampy teen daughter Cassie (Joanna Levesque, whom your kids know as the singer JoJo), thug tweener son Carl (Josh Hutcherson, ''Zathura") -- are looking forward to a vacation in Hawaii, but Bob's boss, played with twitchy Type-A neurosis by Will Arnett of ''Arrested Development," lowers the boom: Be in Colorado for the big merger meeting or you're fired.
Without telling the family, Bob switches plans and rents a recreational vehicle the size of Rhode Island -- everyone pile in for a cross-country bonding experience! The results play like ''National Lampoon's Vacation" with a holding tank of excrement and a lot less nerve.
As written by Geoff Rodkey (''Daddy Day Care," ''The Shaggy Dog"), ''RV" is a Murphy's Law movie: Everything that can go wrong very quickly does. The vehicle coasts backward at will and is promptly dubbed ''The Rolling Turd" (which prompted the child two seats away from me to ask his father, ''Daddy, what's a turd?" -- these are precious moments, folks). The septic tank clogs and erupts, covering Bob in poo; I could work up a metaphor here but it's just too easy. There are raccoons in the oven. Worse, there are hicks in the RV camps, in particular the way-too-friendly Gornickes: Travis (Jeff Daniels), Marie Jo (Kristen Chenoweth), and their three kids.
Like most modern comedies, ''RV" is paralyzed between ridiculing the Gornickes and worshiping them as the salt of the earth. (''Vacation" settled for ridicule and was impressively mean.) The movie asks us to laugh at these blue-collar mutants while putting up with Bob and his loathsome, pampered brood, then trowels on feel-good reconciliation at the end and expects us to buy it. In a way, ''RV" is as spineless as its hero.
Still, the relentless litany of disaster gets some giggles. Sonnenfeld uses dry timing to play against the grain of slapstick -- this is a director who learned his trade shooting Coen brothers movies, after all -- and Williams seems game for just about anything. The sequence in which Bob drives his behemoth over a mountain road and gets stuck, teetering like a compass needle, at the top, is pulled off with the verve of an old ''Road Runner" cartoon.
There are family moments that sting, too: the scene where Jamie, Cassie, and Carl all plug in their iPods and sing separate songs at peak volume while Bob drives miserably on is a wickedly jaundiced snapshot of the modern American family, upper-middle-class division. ''RV" has teeth -- more teeth than the last few Steve Martin films, anyway -- but it's terrified to bite down, knowing that the paying audience would feel it more than anyone. The movie hints that Dopey Dads may be silly but that the alternatives -- Psycho Dad, Despairing Dad, Suicidal Dad -- are too painful to consider. As for Well-Adjusted Dad, who wants to see that?
Ty Burr can be reached at email@example.com.