In newspapers, on television and even on the streets, violence occurs with such tragic regularity that it has become commonplace. But on stage, violence can still shock, and Washington theatergoers should prepare for some pretty rough rides with the opening of two shows, "Scheherazade" at Horizons and "Sharon and Billy" at Woolly Mammoth, both making their Washington premieres this week.

"I guess I'll have to live with my work being known as a rape play," says author Marisha Chamberlain of "Scheherazade." The drama gets fast and furious in the first minutes when a woman is viciously raped; she then must outwit the attacker, who seems bent on murder. Horizons will use low lights in the rape simulation, though the attack scenes, coordinated by a fight choreographer, will be as realistic as possible. "Violence comes quickly and senselessly, without warning, but that's not the real subject of the play," says Chamberlain. "It's more about how violence continues in the mind, delivering consequences that are relentless. The pain of trauma is warping, but, on the positive side, this is about surviving that."

Woolly Mammoth's show, part of its "Comedy Descending" series, will mix pleasure and pain. Written by Alan Browne, "Sharon and Billy" focuses on a nostalgic '50s middle-class family -- but with the "dark underside gradually exposed," says director Howard Shalwitz. Along with the perfect scenes of a cheery dinner table, this "dramedy" touches on incest and abuse. "It's really an emotional odyssey, because it tears the audience in two directions simultaneously," says Shalwitz. "The '50s had such a dreamy facade; it was a time that everything seemed to be new and happy. But riding just under all of it were inklings and undercurrents that things were not quite right." Shalwitz promises laughs, but adds, "Some of it is pretty harrowing."

"Scheherazade" opens tonight; for ticket information call 342-5504. "Sharon and Billy" previews Tuesday; for ticket information call 393-3939.