This is Mike Kellin's final film. He was sick during filming, but did his best to conceal it. He died of lung cancer in August 1983, three months before the film's release.
Willy Kuskin, who plays one of the bullied campers, was genuinely bullied by the other kids during filming. Frank Trent Saladino, who played a camp counselor, had to step in when the other cast members took things too far.
Felissa Rose (Angela), Karen Fields (Judy), and Katherine Kamhi (Meg) were actually all quite close during filming. Katherine Kamhi said the scene where they throw Angela into the water was hard for her to shoot for that reason.
Felissa Rose was only thirteen at the time, which is unusual for a feature film. Studios usually cast actors 18 and over who look younger because of restrictions on using actors under 18 for extended-hour shoots. Also, at 13, she was too young to see her own movie in theaters.
Felissa Rose said in an interview that she wore a bra designed to keep her breasts "flat as a board," though she joked that she was only 13, so there wasn't much to flatten.