It’s not easy playing the idol of hundreds of thousands of preschoolers, but Roger Kraus is coping.

Kraus, a 26-year-old actor from New York, was plucked from an open Equity audition to play Steve, the human star of “Blue’s Clues Live: Blue’s Birthday Party,” the stage show that opens Friday night in a series of six shows at Merrill Auditorium in Portland.

The touring stage show is adapted from the TV show “Blue’s Clues,” which airs at 10 a.m. and 12:30 p.m. weekdays on Nickelodeon and at 8 a.m. Saturdays on CBS. Nearly 15 million viewers watch “Blue’s Clues” each month in the United States, and the series airs in more than 60 countries around the world. It’s a licensing bonanza as well, with Blue’s Clues books, toys, games, videos, CD-ROMs, bath products, toothpaste, baby products and applesauce being marketed.

“Blue’s Clues” stars Steve, the human host, and Blue, his energetic, computer-generated girl puppy. Steve invites young viewers into his world to help him solve the day’s puzzles with Blue and their friends. Clues are marked with a blue paw print, and are written down in Steve’s “handy dandy notebook.” Led by Steve, viewers study the three clues in each episode to figure out what Blue is trying to tell them.

In the stage show “Blue’s Birthday Party,” Steve and Blue’s friends, including Tickety Tock, Slippery Soap, Mr. Salt, Mrs. Pepper and Periwinkle, try to determine what Blue wants for her birthday, based on the clues she’s supplying. Each child receives a handy dandy notebook and crayon upon entering the auditorium to keep track of the clues. The show has two 30-minute acts, with a 15-minute intermission.

Kraus admits it’s been a little daunting filling the green-striped shirt of Steve, originated by actor Steve Burns for the TV show in 1996.

“It’s hard being Steve,” he said from a tour stop in Toledo, Ohio. “The role has been written well, and the guidelines for the character have been well-established. But Steve Burns created the role, and even called the character Steve. People will come up to me and say, ‘You’re not the real Steve.’ But once they see the green-striped shirt, kids are willing to go along with it. It’s only strange at first, until people realize it’s possible for Steve to be this character that someone else could interpret.”

So who is Steve? Kraus asked that same question of Angela Santomero, co-author of the stage show and co-creator and co-executive producer of the TV series.

“She sees Steve as a camp counselor, somebody who knows enough to be responsible and live on his own, but someone who still needs help from other people, in this case, the children,” Kraus explained.

With quite a few children in his immediate family, Kraus was familiar with “Blue’s Clues” before he got the role of Steve.

“I’ve always liked the show, and the way Steve doesn’t condescend to the children,” he said. “I only found out later how much work goes into preparing the show. I was also aware of the live show and had waited to see an audition for it.”

So has it been difficult to be the only human character in the production?

“I thought it would be, but it’s been just the opposite on the live show,” Kraus said. “I’m lucky to work with 12 Equity actors, and that makes it very easy. It’s extraordinary the way that puppetry and costume character work is all done live.”

Kraus has done theater both for adults and for children, and he enjoys the reaction from the youngsters.

“It’s the lack of cynicism,” he said. “Acting is about ‘what if,’ about the suspension of reality and going with the idea, and a kid is so much more open to that than adults. Kids see how willing you are to take the journey, and they’re willing to follow you.”

So, through mid-September, Kraus as Steve will be leading children into the world of “Blue’s Clues.”

“I was happy just being the idol of my 13 nieces and nephews,” he said. “It’s been great to meet the kids, get responses from them and then go from there.”

“Blue’s Clues Live: Blue’s Birthday Party” will be staged at 7 p.m. Friday, 11 a.m., 2 and 5 p.m. Saturday and 11 a.m. and 2 p.m. Sunday at Merrill Auditorium, 20 Myrtle St., Portland. For tickets, call 842-0800 or access www.porttix.com.