“The X-Files,” which debuted on the Fox television network 20 years ago last month, was “the beginning of appointment television,” with families and groups of friends gathering together to watch the science-fiction drama, said Gillian Anderson, one of its lead actors.

Anderson, who played FBI Special Agent Dana Scully, discussed the series with David Duchovny, who played Special Agent Fox Mulder, on Saturday night at the Paley Center for Media in New York. Their characters investigated unsolved cases involving paranormal phenomena.

Their memories of individual episodes were far sketchier than that of the moderator, Keith Uhlich, staff film writer at Time Out New York, and many in the audience. That could be attributed to the work schedule required to produce two dozen episodes a season.

That tough schedule also accounted for why Anderson and Duchovny were in bad moods at every photo shoot they did once the show gained popularity, they said. The shoots were on weekends and “it was all day and that’s your one moment off,” Duchovny said.

Anderson said she began to realize that the series was a hit in its third season. “We were doing interviews every week,” and the interviewers kept mentioning the show’s popularity.

“The X-Files” was the longest-running U.S. science-fiction series when it ended after nine seasons in 2002. Two “X-Files” movies were released, in 1998 and 2008.

Both actors said they took the role because it was a job. “Whoever expects anything to be a hit?” Duchovny asked, adding that he originally thought the show was about aliens. “Eventually you have to see the alien, then it’s over .”

Anderson and Duchovny said they met at “The X-Files” audition when she asked him to practice a scene with her. Duchovny said only one other actor was considered for his role, while Anderson said several, including Cynthia Nixon and Jill Hennessey, competed for her part.

She remembered that her second audition was on a Thursday and by Saturday, they were in Vancouver, British Columbia, to shoot the pilot episode.

Asked about his appearance in a red Speedo, Duchovny said the show’s creator, Chris Carter, had wanted him to wear boardshorts. “I said nobody swims in boardshorts,” so he wore his own suit. “I have regretted it ever since.”

Duchovny also was asked about an episode that used about 300 cockroaches. “I grew up here in the city so cockroaches to me … they don’t bother me at all.”

Anderson said she especially enjoyed episodes, such as those written by Darin Morgan, where the plot was funnier than usual. “I love doing comedy, and it was such a wonderful break for us in the midst of all this serious life and death.”

Duchovny called Morgan’s writing “superior.” “He managed to be very funny, very clever. His world view is kind of bitter and innocent at the same time.”

Duchovny won writing credits for suggesting story ideas to Carter, and he later wrote and directed several episodes. Anderson wrote and directed one episode.

Both actors praised Carter, who remained active in the series for all nine seasons despite also overseeing other shows.

“He took so many risks in the scripts he wrote,” Anderson said. “He’s a perfectionist—I think that comes across in the episodes,” she added.

Asked about the relationship between Mulder and Scully, which became a romance later in the series, Anderson said, “At the beginning, they wanted us to button scenes with looks.”

Later, the actors added touches “because it felt right in the moment,” Duchovny said.

Anderson said some interviewers at that time told her of the “Scully effect,” that the series had inspired more women to seek careers in the sciences. “I thought that was really awesome.”

She also felt “a certain pressure–as a young actress, that I need to behave myself.”

Asked why Anderson had not been a guest star on his recent series “Californication,” on Showtime, Duchovny said, “She knows that wasn’t right.” For the two actors to appear together, “it’d have to be something special or different,” he said.