Comedy improv shows, like the one Brad Sherwood is bringing to the Adler Theatre in Davenport on Friday night, are fueled by audience suggestions.
But there's some stuff that's not good for the tank.
"There are suggestions we're never going to take," said Sherwood, in the "Two Man Group" with fellow "Whose Line Is It Anyway?" performer Colin Mochrie.
"We'll never take 'gynecologist' or 'proctologist' or any of that stuff. That's just a self-contained joke and a full audience of people don't want to see a scene about a pap smear," Sherwood said in a phone interview from his home in Las Vegas. "We're never, ever going to do it.
"People think it's funny and it always gets laughs from the rest of the audience, but in practice that would not be a scene they'd want to have done," he added.
Sherwood, who turns 51 this week, and Mochrie, who turns 58 next week, have performed the two-man show for 15 years, notching more than 700 performances.
"We travel well together, we've known each other for 25 years and the longer we tour together the more like brothers we become," Sherwood said.
"Aesthetically we both like the same things that plays well when we figure out what show we're trying to do," he added. "We don't have big artistic differences of opinion as to what kind of goofy improv show we want."
Sherwood and Mochrie have been regulars on the British version of "Whose Line"; its first American version hosted by Drew Carey, which aired from 1998-2006; and a reboot hosted by Aisha Tyler that has aired during the summers on The CW network since 2013.
The improv games that he and Mochrie play, Sherwood said, are similar to those on "Whose Line," but without a host.
"We basically turn the audience into the source of all games and the moderator for a game that needs someone to chime in and change things," Sherwood said.
"They put us through their paces, but they enjoy it because it's such a collaborative effort between us and them. They're more invested in our show than any show they might passively watch," he added.
Sherwood said he and Mochrie know each other well enough to anticipate what their next move might be, but not so much that they become predictable to the other.
"Even for the purest of improv, you don't want to get into a rut, doing the same things every show," Sherwood said. "And you don't want to know where the other guy is going so you can do something more predictable.
"Because we love doing improv and because of the adrenaline rush of being on stage and making people laugh, we constantly want to go in new directions," he continued.
Born in Chicago and growing up in Santa Fe, N.M., Sherwood said he loved comedy movies and Mad magazine as a kid, but didn't take action until he attended college in Dayton, Ohio.
"I gravitated toward being a funny person, but it wasn't until I saw an improv group in college that I thought, 'Wow, that is cool. I would like to do that,'" he said.
He moved to Los Angeles, began working with improv groups and got training at Second City.
Sherwood said he's done standup comedy twice, and it didn't appeal to him.
"It sounds strange, but there was more pressure going in front of an audience with a group of contained jokes that I already knew," he said. "If they didn't think the jokes were funny, I was like, 'Oh my God, now what?'
"If they don't find that perspective hilarious, you don't have a chance," he added.
A typical audience, Sherwood said, includes former youngsters who cut their comedic teeth watching "Whose Line Is It Anyway?"
"All the kids who grew up with the show are now in their 20s and out buying tickets for things," he said. "We have them coming on purpose, rather than begging their parents to take them to the show."