Eggheads don't take weekends off. They tackle the Sunday crossword, laze by the pool with the latest copy of the Economist and tune in to "Wait, Wait ... Don't Tell Me!," National Public Radio's 12-year-old quiz show that's as heady as "Jeopardy!" and as irreverent as "The Daily Show."

"Dorks. Pretty much all dorks," said host Peter Sagal, describing the kind of fans who will flock to the State Theatre Thursday for a taping of the show that will air next weekend. "They're people just like us who like the combination of high-brow topics and low-brow humor. Public-radio people tend to take themselves a little too seriously, and that can be a little wearing."

There's no way anyone could confuse "Wait" with the BBC News. A routine show may consist of celebrity panelists such as Roy Blount Jr. and Paula Poundstone trying to stump listeners with a bogus story about a senator's stamp collection, announcer Carl Kasell challenging contestants to complete a limerick about BP, and the Air Force Academy superintendent offering his Elvis Presley impersonation.

"The secret is, you have to almost be a complete waste of time, but not entirely," said creator Doug Berman, who also created "Car Talk," the auto advice show that's more about shtick than shock absorbers. "Because it's the weekend, the last thing people want is to be lectured to. You can sneak in a little information, but it almost has to be unnoticed."

That philosophy runs counter to NPR's reputation and may explain why the show took a few years before it captured a wide audience, which now totals more than 3 million.

"We were a sore thumb in a schedule that included things like pygmy flute makers in Tibet," said Berman.

Sagal, who spent much of the early '90s in Minneapolis as a struggling playwright, said the turning point came when the show moved out of the studio and in front of a live audience, primarily in Chicago with about a dozen road trips a year.

"When you're in the studio, nobody knows if you bomb," said Sagal, who shares the quick wit and cadences of Groucho Marx. "But when there's 2,000 people watching, you work harder not to be bad."

Sagal, who picked up hosting duties three months into the program's run, credits Garrison Keillor for showing how an audience should feel like they're part of the show rather than just observers. It's a lesson he learned while serving as an usher at the Fitzgerald Theatre. (Sagal's reverence for Keillor remains strong, even after the "Prairie Home Companion" host publicly scolded him when he snagged a front-row seat only moments before the broadcast began.)

Maybe Keillor will return the compliment by making a guest appearance Thursday night. Whoever shows up has to be a brave soul, because a "Wait" appearance requires more than rattling off a few show-biz anecdotes. It means you'll be tossed some arcane questions that would give Stephen Hawking pause. Sagal said Keillor and others need not worry.

"We are absolutely not in the business of making you look bad," he said. "Nobody cares if you win or lose. We're softball city."

njustin@startribune.com • 612-673-7431