FX's ''It's Always Sunny in Philadelphia" is alt-''Seinfeld." It's three urban guys and a gal, all of them single and dating; but they're younger than NBC's Fab Four, they wear torn T-shirts, and among their many neuroses, hygiene is not a worry. They're not exactly hard-core slackers, since they're responsible enough to own and operate a Philadelphia bar called Paddy's Irish Pub. But they're slackeresque, romping through drunken nights and caffeinated mornings like indie-movie heroes.
And the show, which premieres tonight at 10:30, is a decent little slice of life, if you're a fan of guy comedy. Written by its three male leads, Charlie Day, Rob McElhenney, and Glenn Howerton, it's definitely framed from the perspective of immature men who can't seem to work it out with the ladies. They're always getting into and out of romantic pickles, dumping or being dumped, but their goofball adolescent friendship remains a constant.
And like the firemen on the FX drama ''Rescue Me," or the buddies of HBO's ''Entourage," these guys aren't especially political correct or ethical. In the second episode, for example, Mac (McElhenney) goes to a rally and pretends to be a militant antiabortion activist in order to have sex with a pretty religious extremist. And he succeeds. The guys pull nasty tricks on one another, too, but they keep coming back for more. They don't want high school ever to have to end.
Charlie (Day) is the leader of the pack, a verbal guy with the impish quality of Wally Shawn and the high-pitched whininess of Edward Burns. Dennis (Howerton) is the analytic one, as thoughtful as he is narcissistic. And Dee (Kaitlin Olson) is Dennis's sister, the bartender whose bad judgment with men is an ongoing subplot. Along with Mac, they all try to keep the bar -- and their dignity -- from going under each week.
Tonight's episode is the weakest of the three sent for preview. It's a tired situation that we've seen on so many sitcoms, as the gang goes overboard to prove they're not racist to a black guy dating Dee. In the process, of course, they appear quite racist, or at least overly race-conscious. Even ''Committed," a painfully derivative NBC sitcom from last season, played this little joke to death during its short run.
But the next two episodes are fresher. Next week, a woman tells Charlie she's the father of her child, a situation he learns to exploit. And in two weeks, the guys decide that serving booze to underage kids can be rationalized as a social service, as a way to give them safe harbor. And so our foursome gets heavily caught up in the histrionics of their new high-school-age bar patrons, particularly as the senior prom approaches. Despite their 20-something age bracket, the ''Sunny in Philadelphia" gang have truly found their people.