Jack Blum (casting director, actor, played “Spaz”): Ivan always wanted Bill. There was no question that Ivan wanted Bill.

Reitman: Not only was he my first choice, he was my only choice. I knew how good he was. He’d only been on Saturday Night Live for a year at that point. But he hadn’t really broken out yet. I called him up, pitched him the idea, and of course he said no.

Blum: Even then, long before he was famous, Bill was entirely his own man. And he was holding out.

Goldberg: We were sending scripts around to various minor-league baseball clubs, because Bill was touring with baseball clubs, having fun for the summer, taking a break from Saturday Night Live.

Reitman: My strategy was, I would basically just browbeat him until he did it. And it worked! [Laughs]

Goldberg: At the same time, we’re trying to put all the other pieces together for this thing, like where we’d be shooting. I’d drive all around Canada, visiting various camps to see if they would let us shoot with the campers. A lot of them said, “Forget it, are you kidding me? These are paying customers.” But somehow we got the O.K. from Camp White Pine, which is up in Haliburton, Ontario. I have no idea how we did it.

Reitman: I wanted to shoot in August, while the campers were still there. I thought that would be a great idea, because the movie would feel real. And the campers would serve as relatively inexpensive extras. Now all we had to do was find a cast.

Blum: We wanted to hire mostly unknowns, so we put an ad in the newspaper, saying, “Open casting call for a movie named Summer Camp,” which was its working title. We took over a movie theater for three days, and on the first day there was a line of hundreds of teenagers outside, wrapped around the theater.

Russ Banham (actor, played “Bobby Crockett”): It was summertime, and my kid sister and I decided to go to Jones Beach, which is what kids in Queens do in the summertime. All I had on was a pair of cut-off jeans. No shoes, no shirts, that’s it. I called my answering service, and there’s an urgent message from my agent. “There’s a producer in town today. He’s doing auditions for a movie called Summer Camp.” I was an hour-and-a-half away from Manhattan, so I didn’t have time to go home and change. I went straight to the audition. I walk into this thing with jean shorts and no shirt, looking like I just stepped off the beach. Because I had! All these other actors, whom I used to audition against, they were looking at me, and I could tell they were thinking, “Genius! He’s a genius! Why didn’t I think of that? He even got a sunburn for it!”

Blum: They were having a lot of problems finding the right actor for Spaz. They brought in one actor after another, and Ivan just wasn’t having it. One actor came in, and I thought he was really good. He did this goofy voice for Spaz, and he was really funny. But Ivan was like, “No, that guy’s not Spaz. He’s like a matinee idol. He’s a great-looking guy. He’s not going to be Spaz.” But then he looked at me and said, “You want to audition?” So I got up and basically did exactly what the other actor had done. Same goofy voice, same line readings. And Ivan said, “Great! You’re our Spaz!”