Scary Movie, a parody of every horror flick released since the sound era, has the makings of a hit. Never mind that the Scream flicks are already parodies. That doesn’t bother director Keenan Ivory Wayans (I‘m Gonna Get You Sucka), who knows the value of dumbass laughs. Wayans finds fun uses for two of his actor brothers — Marlon as a pothead film buff who gets shitfaced with the masked killer from Scream, and Shawn as a football stud who sidelines as a gay blade. As for the babe quotient, newcomer Anna Faris does the wholesome Neve Campbell coed bit, leaving the vamping to Shannon Elizabeth (American Pie) and Carmen Electra (Baywatch). I liked Electra’s sendup of Drew Barrymore in Scream; she fights off a masked killer and a bout of flatulence as she runs — stripped to bra and panties, natch — toward her parents’ speeding car, only to get slammed because Mom is giving Dad head. Still, would it be asking too much if the hit-and-miss jokes could maybe nudge an inch beyond the obvious? The Blair Witch Project deserves more of a tweak than showing a close-up of a wool-capped camper, nostrils dripping in fear. And references to non-scare stuff like The Matrix and The Usual Suspects smack of idea deprivation. Way too often, so does this movie.