Big and broad, CBS’ “The McCarthys” tries to bask in the glory of a fractious, colorful nuclear family from Boston (here pronounced Baaahston), with the mild twist that one of the grown sons is gay. The scenario yields all the expected gags, and leaves an able cast — including Tyler Ritter as the son and Laurie Metcalf as his mom — struggling to make much of it. The Eye network has already managed to wring more life than anticipated out of the similarly boisterous “The Millers,” but it will require the luck of the Irish to replicate that feat with this bunch.

Of course, Ritter’s Ronny came out to his kin a while back, but the family continues to wrestle with the particulars. “You’re still gay?” mom asks, seemingly only half kidding, when he mentions it.

Truth be told, though, at least initially Ronny being gay plays like little more than a sitcom device, inasmuch as he doesn’t date, lives a block from his parents’ house (farther than any of his siblings) and still comes home to watch “The Good Wife” with his mother.

The rest of the family, naturally, is deeply invested in Boston’s local sports franchises, a passion heightened by dad’s job as a basketball coach. And it’s that connection that sets up a way to prevent Ronny from moving to Providence (a distance that might as well be Tibet, in his mother’s eyes), as well as creating a second comedy environment beyond the family living room that, based on the pilot, “The McCarthys” pretty desperately needs.

Having lent her knack for the genre to a recurring gig on CBS’ “The Big Bang Theory” (and more recently HBO’s tepid “Getting On”), it’s nice to see Metcalf in a role that showcases her abilities, and she basically sells the notion of a doting mother who’s not quite as cosmopolitan about her son as he (and maybe she) would like her to be. There’s also a touch of nostalgia in another of John Ritter’s children adding a regular sitcom credit to the family resume, even if the take on being gay here represents at best modest progress versus dad’s “Three’s Company” days.

Still, the central mother-son dynamic and its moments of warmth can’t overcome the weariness that permeates the rest of the show and cast, which consists of Ronny’s two buffoonish brothers (Joey McIntyre, Jimmy Dunn), sister (Kelen Coleman) and dad (Jack McGee).

Created by Brian Gallivan, “The McCarthys” will follow the final season of “Two and a Half Men,” and joins a CBS comedy lineup that — even with the respite offered by “Thursday Night Football” — could use an infusion of energy. And while there’s clearly an audience for this sort of fare, the likelihood of “The McCarthys” breaking out of the pack looks about as good as the Celtics winning this season’s NBA title.

TV Review: ‘The McCarthys’

(Series; CBS, Thurs. Oct. 30, 9:30 p.m.)

  • Production: Filmed in Los Angeles by CBS Studios and Sony Pictures Television.
  • Crew: Executive producers, Mike Sikowitz, Will Gluck, Richard Schwartz, Brian Gallivan, Andy Ackerman; director, Ackerman; writer, Gallivan. <strong>30 MIN.</strong>
  • Cast: Tyler Ritter, Joey McIntyre, Jimmy Dunn, Kelen Coleman, Jack McGee, Laurie Metcalf
  • Music By: