'Shameless' (10PM ET Sunday, Showtime) is hard to categorize, and that's just one of the things that makes this promising drama a risky endeavor.

Showtime is betting that people who shell out for premium cable will want to watch the story of a poor family struggling to stay one step ahead of the bill collectors, and that's a big bet.

There's nothing aspirational about the lifestyle of the Gallagher clan; viewers won't be getting a glimpse of an exotic or somehow enviable way of life (hey, even Dexter gets to live in Miami). As is the case with most meaty cable dramas, there doesn't appear to be a substantial season-long arc building in the first season. The stories that keep things perking along -- and 'Shameless' certainly isn't short of energy -- involve the scams and dodges that somehow put food on the table one day at a time.

Despite all that, 'Shameless' may be a keeper. The performances by William H. Macy as unapologetic drunk Frank Gallagher, Emmy Rossum as his eldest child, Fiona, and Joan Cusack as an eccentric neighbor are richly rewarding, and the show's British creator, Paul Abbott, and American adaptor, John Wells, have made sure of one thing: This isn't a tale full of woe and sorrow.

The Gallaghers aren't generally prone to self-pity, and Abbott and Wells wisely invite the audience to cheer on the Gallagher kids as they navigate lives that have made them wily, cunning and wiser than their years.

Before watching 'Shameless,' I had every expectation that Macy would steal scenes out from under all and sundry, and I wasn't disappointed in that regard. No one else could have carried off this role with the aplomb and honesty that Macy brings to the role of the Gallagher patriarch. Frank does some things that are, frankly, despicable, and his self-justifying rants and querulous self-pity would have been impossible to take from an actor less inherently empathic and likable. Frank's blowsy arrogance, you begin to see, is his only defense against a situation that would otherwise be overwhelming.

Rossum gives as good as she gets as Fiona, who uses her family's endless crises as a way of keeping true intimacy and trust at bay. When the six Gallagher kids' mom left town a couple of years ago, Fiona became the substitute mother of the household, and she uses that role as an excuse not to create a life of her own. She, like the rest of the kids, doesn't necessarily judge Frank for his drinking, but they all find subtle ways to rebel against his abdication of proper parental duties. By taking over Frank's role, she's showing him every day what he should be doing but isn't.

But again, the Gallagher clan doesn't view itself as unfortunate, merely challenged. As Abbott says in the press notes accompanying the show "Nobody wants to watch a series that revolves around an impoverished family," so his game plan was always to throw "slightly absurdist" plots at the audience. As Abbott says, "It takes the audience's eye off the ball as to what they're watching."

It's a smart technique, and in the first three episodes, the family's scams, adventures and predicaments are interesting enough to keep things perking along, though the episodes occasionally feel a bit long (their running time is generally around 52 or 53 minutes). The danger of a sprawling ensemble show is that there are sometimes too many characters to service adequately. Not all of them pull their weight here, but most are at least mildly interesting. Still, if there isn't a season-long arc to pull us in, establishing empathy for a few central characters is even more important.

For those reasons, it's easy to see why the show spends a substantial amount of time on the teenage Gallagher brothers, Lip (Jeremy Allen White) and Ian (Cameron Monaghan). With anything but brilliant casting, this show would have been dead on arrival, but all the Gallagher kids are credible, and these two actors are particularly sensational. Like the gritty, scuffed-up world they inhabit, Lip and Ian seem real and specific, and their scenes together have a wonderful, ribald authenticity. White, in particular, is a revelation as the wry, whipsmart Lip. The kids rarely call Frank out on his terrible parenting, but Lip has a wonderfully casual way of pointing out Dad's hypocrisy with killer deadpan remarks.

Economically, the Gallagher clan isn't going anywhere: They've been stuck at the bottom of the ladder forever, and it takes all the kids' energy just to keep a roof over their heads (Frank gets a monthly disability check that is spent at a local bar). The bigger question is, where is 'Shameless' going? Given that the Gallagher kids are able to fend for themselves and relatively accepting of Frank's limitations, 'Shameless' can sometimes come off as a pretty good indie movie that doesn't have a particular destination in mind. (Blogger Dan Owen and I had an exchange on Twitter about whether UK viewers are more accepting of characters without overt aspirations. I tend to thing UK viewers are more tolerant of that, and Dan had interesting thoughts on the subject here.)

It's admirable that the show, like the family, plans to live by its wits, and there is wit aplenty on display (despite the occasional bit of clunky, on-the-nose dialogue). Fiona's rocky romance with a handsome guy named Steve (Justin Chatwin) provides one ongoing story (though it's a slender one), and when Frank begins to butter up his agoraphobic neighbor, Sheila, Macy and Cusack engage in a wonderfully comic acting duet.

But will 'Shameless' have enough momentum to keep viewers hooked through the end of a season? As much as I like the cast, I wonder if I'll still be interested in the Gallagher shenanigans by the seventh or eighth episode the season. That remains to be seen, but so far there's enough here to keep me coming back to visit this squabbling Chicago clan.

An interview with 'Shameless' star William H. Macy is here.


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