“The Blackening” is a slasher movie that’s also a slapdash enjoyable social satire. That the satire turns out to be sharper than the scares isn’t a problem – it’s all part of the film’s slovenly demonic party atmosphere. The set-up, which feels like a “Friday the 13th” sequel by way of “Bodies Bodies Bodies,” reunites nine old college chums to celebrate Juneteenth weekend in a big roomy house they’ve rented near the woods. As Tina Turner’s cover of “I Can’t Stand the Rain” spins on the turntable, the first two to arrive, Morgan and Shawn, find their way to the basement game room, which has shelves of old board games, an ancient TV set, a Ouija board and a prominently displayed game called The Blackening. Taking the box cover off, they discover, to their horror, that there’s a plastic Sambo head in the middle of the board, which asks questions like “What’s the first Black character to survive a horror movie?” For a few minutes, we’re in the terrain of “Scream” by way of “Get Out.” When the others arrive, they go down to the game room and the television set suddenly pops on. We see one of those ancient this-is-a-test-of-the-emergency-broadcast-system screens with another Sambo face in the middle of it, as “Camptown Races” plays on the banjo and then the TV image shifts to black-and-white video of what happened to Morgan and Shawn. It’s not a pretty picture. For a moment, we seem to be in the realm of “Saw” – but as soon as we see the killer, hidden behind a bondage mask ascribed with a grotesque blackface caricature, the mood of racist hostility and anxiety begins to conjure, more than ever, a certain sunken place. “Get Out” was a great horror movie and, in its way, a serious one that echoed the deep-dish paranoia of films like “Rosemary’s Baby.” “The Blackening” has no such pretensions. The script, co-written by Tracy Oliver and Dewayne Perkins, is full of dialogue that pops with comical tossed-off self-awareness. “The Blackening” is framed as a thriller, but the way that the veteran director Tim Story has staged it, the entire movie turns out to be a riff – a highly barbed and witty one – on Black in-jokes, Black pop-culture referentiality and Blackness itself. This is the sort of movie that pivots around the inside intricacies of the card game Spades, and in which a character looks at Nnamdi, the group’s tall and handsome player, and says, “You are an original African. You’re a still-in-its-original-packaging Black.” Or the Park Ranger shows up and is greeted with the line, “I’ve never been so happy to a see a white savior.” This is funny-nasty stuff, all delivered in the spirit of characters who reveal themselves, the film implies, in a way they wouldn’t if white people were around. The actors make their presence felt, from Melvin Gregg as King, the arrogant ex-gangsta who feels he’s doing penance by having married a white woman, to Antoinette Robinson and Grace Byers as Lisa and Allison, who carry on conversations so rooted in the intensity of their Black sisterhood that they’re telepathic, to Jermaine Fowler as Clifton, the group nerd, who with his lopsided gawk and fixation on the superiority of the Android to the iPhone at first strikes us as an innocuous geek, but he turns out to be a geek from hell. There’s a surprise resonance to Fowler’s performance. This is a movie that culminates in the killer asking the group’s members to save themselves by sacrificing the one of them who’s “the Blackest.” But what does that mean? As our cliché definitions start to fall away, we realize that the very notion of being “the Blackest” is a self-destructive power trip. The terrific ad tagline of “The Blackening” is, of course, a reference to a long-standing trope and eye-rolling gripe: that the Black character in a horror film always dies first. But the real joke is how a perception like that one has become part of popular culture. The Blackening game keeps testing the characters’ knowledge of trivia, with brain-teasers like: Name the five Black actors who appeared on “Friends.” By the time they’re trying to answer that one, the movie is getting us to chortle at the bitter irony of it all – that though a renegade pop scholasticism binds these characters as surely at it does the horror geeks of the “Scream” films, in a way it carries more urgency here, since every piece of trivia channels issues of inclusion vs. being on the outside looking in. It’s a tribute to “The Blackening” that it invites everyone in the audience to feel included in its diabolically socially competitive, naughty-clever games.