On-screen McAdams exudes just the right blend of sugar-sweet charm and menacing intimidation to be totally believable as Regina; however in real life she anything but resembles her character. Director Mark Waters definitely noticed the dissimilarities between the character and the young actress.
"I think it’s true that you have to cast a nice girl to play a mean girl, just like you have to cast a smart person to play a dumb person,” says Waters. “Rachel is this incredibly hardworking, really terrific girl who can be totally evil on camera, but is actually incredibly nice in person. Which is lucky for all us,” he adds with a grin. “If she was anything like Regina in real life it would be a nightmare.”
The filmmakers searched long and hard to find the right actors to play the roles of Janis, Damian, Gretchen, Karen and Aaron, all of whom help Cady as she navigates the ups and downs of her first year of high school. Casting a wide net, they auditioned young actors and actresses between the ages of 15 and 25 in New York, Los Angeles, Toronto, Vancouver and Chicago.
Portraying Gretchen and Karen, Regina’s sidekicks, best friends and devoted followers are Lacey Chabert and Amanda Seyfried. Together the three make up The Plastics, the most feared, revered and ultra-fashionable clique at North Shore.
Chabert. who plays Gretchen Weiners, maintains that her character is "only mean by association” and, because she has a tendency to spill everyone’s secrets, it gets her into a lot of trouble. “She’s incredibly wealthy because her father is the inventor of Toaster Strudel, and she loves people to know that,” laughs Chabert. “She’s also incredibly insecure, constantly having anxiety attacks that Regina is going to kick her out of The Plastics, and fearful that she’ll lose her status. Therefore, she’s terrified of Regina, but at the same time idolizes her. She just knows that one day she’s going to cross the line and wear the wrong color or something and cap — she’ll be kicked out and washed up.”
Having spent her high school years playing the role of Claudia on the hit television series “Party of Five,” Chabert was tutored in a trailer on a studio lot, so she understands Cady’s dilemma of missing out on a normal high school experience. “That’s not to say that I couldn’t grasp my own character’s experience,” Chabert points out. “In fact, the script is so vividly written that all the characters just jumped off the page.
Newcomer Amanda Seyfried says she was thrilled when she was cast as one of The Plastics and that she didn’t mind being cast as the “dumb” one of the group. “Karen may be clueless,” observes Seyfried, “but she’s also fun-loving and energetic.”
While The Plastics are the creme de la creme of the North Shore girls, Aaron Samuels, all-round-nice-guy, hunk du jour and the object of Cady’s first high school crush, not to mention Regina’s ex-boyfriend, is definitely the big man on campus. Jonathan Bennett. who portrays Aaron, admits that the character is not unlike the guy he was in high school.