One of the lessons drilled into any young writer is a simple one: "Write what you know." The problem, at least when applying this rule to television, is that what many of the people who work in television know about is television and nothing but, which is why there have been so many shows over the years — most of them failures — about characters who work in the entertainment industry.

Inside showbiz stories aren't inherently bad, as seven seasons of "30 Rock," or even a showbiz-adjacent series like "Curb Your Enthusiasm" have amply demonstrated. But watching HBO's new comedy series "Doll & Em," all I could think about was how much I wished the setting was anywhere but Hollywood.

The series was created by its stars, Dolly Wells and Emily Mortimer (who already has an HBO job on "The Newsroom"), and they play fictionalized versions of themselves. In reality, Wells is a working actress, but here she's simply the childhood friend of Em (who appears to be more famous than Mortimer in real life) who moves in with Em after a bad breakup and takes a job as her personal assistant. And the new job creates a very blurry boundary between the moments when Em is treating Doll as her best friend and when she wants her to be an employee.

As written by Wells and Mortimer, sometimes in collaboration with the show's chief director, Azazel Jacobs, "Doll & Em" is excellent at one thing: depicting the complicated ebbs and flows of a kind of female friendship where one friend is content only when she's the alpha, and will badly undercut the beta to make this clear. Whether or not the stars' own friendship is anything like this, the subtle and not-so-subtle ways that Em abuses (sometimes actively, sometimes obliviously) Doll ring absolutely true.

The problem is that this dark, observant comedy about an unhealthy friendship is inserted into a familiar Hollywood satire about pampered, neurotic movie stars (guest stars in the three episodes I've seen include Susan Sarandon and John Cusack) and the people who enable them. And every beat of that material is predictable and clumsy and unfunny. Like "Curb," "The Office" and "Extras," "Doll & Em" is a comedy of discomfort, but because you can see the punchlines coming from several miles away, the sense of discomfort is vastly stronger than the laughter that is meant to compensate for it.

I don't know for sure that the show would be vastly improved if Em was, say, a powerful investment banker, or a politician, or some other job that still allowed her to sweetly lord her status over Doll. But I know that this setting doesn't really work at all, and obscures a promising core element that feels like it would work better elsewhere.

I would assume that HBO — which acquired the show from Sky, who produced it in the UK — recognizes that it has a flawed product on its hands. It's not only airing the six episodes back-to-back over three straight weeks, but airing them on Wednesdays at 10 and 10:30. In the past, HBO has occasionally moved its scripted shows to Mondays if the schedule got too full, but I believe the last time HBO regularly aired a scripted show in a Wednesday timeslot was "The Larry Sanders Show" back in the mid-'90s.

The idea of a TV network acquiring an autobiographical project from one of its stars and then dumping it in an out of the way place once they get a good look at it feels like the sort of plot "Doll & Em" might tell in a future season. But that, again, wouldn't be the show playing to its strength.

Alan Sepinwall may be reached at sepinwall@hitfix.com