In 2007, Australian stand-up comic Jim Jefferies was attacked onstage in the UK by a guy who felt he’d been too hard on a female heckler. The man took offense when Jefferies said to her, “I’ll leave you alone now, just like your dad did. Shame your grandfather didn’t.”

If Jefferies’s joke, a bit of Freudian taunting with an incest zinger, makes you sympathize with the attacker for even an instant, you probably won’t like Jefferies’s new comedy, “Legit.” The FX series, which premieres Thursday night at 10:30, is full of material that relies on giddy vulgarity, political incorrectness, and sexual frankness. One of the central characters in “Legit” is a guy with muscular dystrophy who can’t move, and his predicament — he’s a virgin at 32 and wants to go to a hooker — is the foundation of the first few episodes. The show has a vibe that at moments recalls Howard Stern’s Wack Pack.