The major theme recurring in the movie is that appearances tend to cover up someone’s true personality and that there is more than meets the eye to anyone, no matter how stereotypical they look or act on the outside. A good example (among many) of this would be of the character of Claire, who does seem like the stereotypical conceited socialite who has a charmed life with a rich family, something that is routinely mocked by Bender, however she reveals that her parents have been on the edge of divorce and use her as a tool to get back at each other. The group’s nerd, Brian is also talked down to by Bender for seemingly not having a life as rough as his, due to him not being physically abused, as he sardonically acts out a skit about how much easier Brian’s home life is than his. This was before he admitted that he considered suicide due to his overbearing mother pressuring to keep straight A’s in school, which is intensified after failing his “easy A” shop class, by bringing a flare gun to school, which then accidentally goes off in his locker, causing him to spend the day in detention. And for recluse Allison, who initially comes off as both aloof and slightly deranged, remaining mostly silent during most of the first half of the movie, is actually revealed to be an act as she assumes this role due to being neglected at home and being socially inept.
Another theme that is also present in the movie is the rebelling against unjust authority, as the major adult characters in the movie are antagonistic in one way or another. The school principal, Richard Vernon was the man who sent all of the five in detention. While during their stay he regularly talks down to his students and is constantly at odds with the criminal, Bender, even to the point of almost getting into a physical confrontation with him. Another example of a so-called “villain” in the movie would be the parents. Though they get only four minutes of screentime combined, the teen’s parents have a big part of the movie, and are the reason for the angst which causes them to lash out, such as the fact that Bender lives with a father who physically abuses him, even giving him a cigarette burn on his arm at a younger age, causing him to act out band with Andy’s father being a loudmouthed narcissist who lives on vicariously through his son, espousing an extreme “winners-only-get-first-place” attitude. Andy’s dad also in one way, motivated him to act out on a prank on a weaker underclassman in the locker room, causing him detention.