The WGA's first walkout in 19 years immediately shut down late-night talk shows such as "The Tonight Show with Jay Leno" and "Late Show With David Letterman," forcing networks to air reruns Monday, the New York Daily News reported Tuesday.
A lengthy strike could also affect hit shows like "Lost," "24" and "CSI: Miami," which only have so many scripts completed ahead of the show's shooting schedules.
"This is a battle of wills," Fey told the Daily News.
"I'm a writer first. ... I would never have an acting job if I hadn't written first," said Fey, who started out as a writer and player on "Saturday Night Live" and who now co-produces, writes and stars in the NBC comedy "30 Rock."
In Los Angeles, Leno rode up on his motorcycle and passed out doughnuts to writers on a picket line.
"I've been working with these people for 20 years. Without them, I'm not funny. I'm a dead man," Leno told the Los Angeles Times.