Although the show claimed to be reality TV with people portraying themselves, it became scripted right after Lauren Conrad left the show.
The episode that showed Heidi Montag and Spencer Pratt's wedding was difficult to shoot. Lauren Conrad and Kristin Cavallari decided the night before to go to the wedding and the producers wanted everyone to be shocked. They stuck Lauren in one room and Kristin in the other, but the generator in the church went out. The girls waited in the church basement for hours and once the generator came back up, Kristin and Lauren came in first and second respectively. The actual reactions of the cast were in fact real.
Justin Bobby was very reluctant to be on the show, but he wanted to be with Audrina Patridge. He ended up signing on.
Audrina is the only one to appear in all episodes besides the specials. Heidi Montag left the show with Spencer Pratt after season 6 episode 4. After that, she was only credited in the rest of the episodes. Lauren Conrad quit the show after season 5 episode 10.