If you need an example of how not to conduct an apocalypse, look no further than “Legion.”

Among all the available options, the God in “Legion” chooses to end the world by turning small children, the elderly and people with offbeat clothes and accessories (ice cream truck drivers, guys wearing party hats, etc.) into monsters. God, equipped with an army of bad-ass, sword-swinging angels, and, well, dominion over everything, decided to outsource Armageddon to the least qualified, it seems. File this decision under the “works in mysterious ways” category if you must, but know that this inexplicable apocalypse is actually the least of the many problems that plague “Legion.”

The biggest problem may be the story itself. Writer/director Scott Stewart, who until now mostly worked as a visual effects artist, seems to have taken a script from “The Terminator” and replaced all instances of the word “robot” with “angel” and “the future” with “heaven.” Except in this case, the angel sent from heaven—Michael, played by a far-too-serious Paul Bettany—wants to protect the pregnant lady he’s charged with finding, so maybe “Legion” is kind of like “The Terminator” with bits of “Terminator 2” mixed in. That lady is Charlie (Adrianne Palicki), who’s biding her time at a dingy diner at the edge of the desert until her baby pops out.

God, apparently tired of humanity, wants to wipe everyone out, and all the angels, save for Michael, agree. (It’s worth asking what, exactly, put God over the edge, but you can file that under “mysterious ways,” as well). The baby, it seems, will save humanity from utter destruction at the hands of a bunch of robots—I mean, angels—and eventually convince God that humanity is worth keeping around.

Whatever plot points Stewart didn’t crib from “The Terminator,” he glossed over using some shaky theology, and from this weak foundation, “Legion” leaps fearlessly into utter awfulness. It’s not even the sort of so-awful-it’s-good kind of awful. “Legion” is a straight-up bad movie, bereft of interesting characters, memorable dialogue or even cool fight scenes.

The angels in “Legion” look awesome—fully armored, equipped with swords and giant maces, covered in tattoos in some angelic language—but only one angel actually shows up, and that’s not until the end. We should be treated to what the film’s title promises—a legion of angels smashing their way through buildings and bashing humans. Instead, we get old ladies and ice cream men with bad teeth and gangly limbs scrabbling up the walls of a dirty diner. With such cool visual possibilities, why stop there? Are all the angels on a coffee break?

“Legion” settles for mediocrity in every other area, too, so it’s not much of a surprise. The cast, headed by Dennis Quaid (who, based on his recent appearances in “Pandorum” and “G.I. Joe,” is mostly interested in collecting an easy paycheck these days), is full of TV refugees who are simply adequate. But it’s not like they’ve got much to work with—Stewart’s script is just as full of clunky dialogue as it is half-baked ideas about angels.

Worst of all, nothing much really happens. Some monsters attack, and then there are prolonged periods during which Quaid and the other survivors stuck in the diner with Charlie and her angel have boring conversations. Then some other monsters attack and, well, you get the idea. That the monster attacks are almost as dull as the conversations is an unfortunate indicator of the movie’s quality.

Perhaps that’s the underlying message of “Legion”—that God does exist and is, unfortunately for us, mostly boring, lazy and unoriginal. Or maybe it’s just “Legion” that’s boring, lazy and unoriginal. Either way, let’s hope global warming or nuclear destruction work out for us—those are at least some apocalyptic scenarios worth getting excited about.