Saying that a show plays on two levels can seldom be taken quite so literally as in “The 100,” a better-than-average CW sci-fi drama that splits its story into two halves: The 100 young people of the title, who’ve been jettisoned down to see if they can re-inhabit a nuclear-ravaged Earth and establish a society, “Lord of the Flies” style; and the adults above on a floating space station, wondering how long their resources will hold out, in what amounts to a poor man’s “Battlestar Galactica.” Parts of the plot and casting fall short, but there are enough elements in this ambitious serial to hope the show doesn’t run out of ideas — or air.

The premiere of the series, based on a book by Kass Morgan, moves a little too fast in establishing the rules, introducing a space-bound society 97 years after nuclear annihilation, where any crime is a capital offense — unless the perpetrator happens to be under the age of 18.

So the equivalent of a juvenile-hall facility (played by actors who generally look considerably older) are shipped down to the planet. It’s an act of necessity, unbeknownst to the inhabitants, because the Ark — the collection of space stations where three generations have lived — is running short of air and will soon have to start “floating” people.

Think of the colonists as the expendables, only with acne instead of an AARP plan.

Among the kid contingent is Clarke (Eliza Taylor), the daughter of the station’s doctor, Abby (Paige Turco), whose husband was turned into space debris for wanting to go public with the bad news. This has put Abby at odds with the group’s leader, Chancellor Jaha (Isaiah Washington, rebounding from his “Grey’s Anatomy” floating), and his No. 2 (“Lost’s” Henry Ian Cusick), the latter appearing a bit too eager to impose a mass death sentence to help preserve precious resources.

Clarke’s version of Eve, meanwhile, immediately finds a potential Adam in Finn (Thomas McDonell), though like any apocalyptic romance, it’s not without complications. She also butts heads with the colonists’ de facto leader (Bob Morley), whose resentment against those in power comes with its own detailed backstory.

Developed by Jason Rothenberg, “The 100” plays best up in space, and at times feels a little too much like “Futuristic Earth, 90210” down on the planet, where — heady over their exposure to fresh air — the youthful pioneers begin to feud and squabble, as well as discover all is not paradise. That includes the realization there might be more than just two-headed deer to endanger them. (The threats are generally teased out in a manner meant to build suspense, but that also suggests there wasn’t a budget to do a whole lot more.)

Nitpickers will complain about how being marooned on an annihilated Earth clearly hasn’t interrupted the flow of hair and makeup products, or the fact the kids occasionally behave like they’re in Daytona Beach for spring break. Yet even with some shaky performances, there’s enough happening — including a few genuine surprises in the first half-dozen episodes — to sustain interest.

In success, of course, “The 100” isn’t just a reference to those trying to re-inhabit Earth, but also a syndication-friendly wish as to how many episodes CW would like the show to run. And there’s certainly no shortage of narrative possibilities.

Helped by its “Arrow” lead-in, the series might have a shot at survival. Still, as they say both in TV and around the Ark, just don’t hold your breath.

TV Review: CW’s ‘The 100’

<p>(Series; CW, Wed. March 19, 9 p.m.)</p>

  • Production: <p>Filmed in Vancouver by Alloy Entertainment in association with Warner Bros. Television.</p>
  • Crew: <p>Executive producers, Matt Miller, Jason Rothenberg, Bharat Nalluri, Leslie Morgenstein, Gina Girolamo; producer, Jae Marchant; director, Nalluri; writer, Rothenberg; based on the book by Kass Morgan; director, Nalluri; camera, Nathaniel Goodman; production designer, Matthew Budgeon; editor, Hunter M. Via; music, Even Frankfort, Marc “Doc” Dauer, Liz Phair; casting, Barbara Fiorentino, Danielle Aufiero. 60 MIN.</p>
  • Cast: <p>Eliza Taylor, Paige Turco, Thomas McDonell, Isaiah Washington, Henry Ian Cusick, Marie Avgeropoulos, Bob Morley, Devon Bostick, Christopher Larkin</p>