IDIOTS MIGHT GRIN when they see a fiery-eyed, supernatural Peter Dinklage give a knowing smile while avenging his bloody death at the teeth and talons of a hell-spawned succubus near the end of Knights of Badassdom. (Whoops! Spoiler alert!) He's a badass in Game of Thrones! And now he's a badass in a movie about live-action role-playing! How perfect!

But that's an accident. A stupid accident. Knights of Badassdom was shot almost three years ago, before the benefit of a thematic tie-in with a far superior product. And until it was summoned forth, it had been left to rot in the Negative Material Plane of Tinseltown. Where it belongs.

Knights of Badassdom doesn't know what kind of campy movie it wants to be. It starts off with promise, as the world is ready for a poke at role-playing nerds done with nuance, intelligence, and some in-the-know affection. But the gags (I laughed maybe twice during the whole movie, and I don't even remember what at) never get any deeper than sissy/masturbation/thee-thou-verily riffs.

Then the whole thing lurches between a stoner-style breakup comedy and gore fest, both lacking cleverness. The occult business comes after an insecure wannabe wizard (Steve Zahn) overreaches by using a real-life occult spell book to summon a demon—except the demon looks just like his heartbroken friend's ex-girlfriend. I got so bored, I dozed off during the big battle at the end.

And yet, almost in spite of itself, Knights still does two things okay: Firefly's Summer Glau plays the toughest, smartest, and most fearless character in the whole movie, and True Blood's Ryan Kwanten is a pretty wicked metal singer. Metal winds up saving the day when Dinklage can't. If only it could have saved this shitshow of a movie.