ONTD

With her sidesplitting performance in the over-the-top wedding comedy Bachelorette—plus a slew of other wildly different roles—the actress goes from droll sidekick to breakout star.

With her sly smile and dancing green eyes, Lizzy Caplan is alluring even when delivering a withering put-down. That's something she does often, with a trademark deadpan: In roles ranging from the spurned friend in Mean Girls who tells Lindsay Lohan she smells "like a baby prostitute" to the hard-ass lawyer on New Girl who calls out Zooey Deschanel for her "Bluebirds help me dress in the morning" persona, Caplan has been upbraiding leading ladies for almost a decade. Now the 30-year-old Los Angeles native has become a leading lady herself, thanks to a smorgasbord of new projects. As a promiscuous, coked-out bridesmaid in this month's raunchy comedy Bachelorette, she describes her personal fellatio-ranking system—"Ten being I'm, you know, choking"—to a random dude on a plane, a bit that's destined to become legendary. "If people start saying things to me on the street from the blow-job monologue—yikes," Caplan says. "My poor dad." She also plays a basket case who accidentally makes a sex tape in the indie 3, 2, 1 . . . Frankie Go Boom, also out this month; a commitmentphobe torn between suitors in the December rom-com Save the Date; and a controversial sexologist in Showtime's historical drama Masters of Sex, premiering next year. "Lots of people only know my . . . biting characters," Caplan admits. "But I know I can do more than that. If you want to just do the same thing, don't be an actor."