When they first started filming, Amanda Bynes couldn't play soccer at all. Nevertheless, Bynes does most of her own playing in the movie.
As Duke comes into the shower room and walks by Malcolm, he snaps the towel at Malcolm's head to get him to shut up about the dorm pamphlet life while ranting at Sebastian. Channing Tatum really hit James Snyder in the eye with the towel and James' reaction is real.
When holding auditions for the role of Duke, Amanda Bynes fought for the producers to choose Channing Tatum, who at the time had never had a leading film role and was largely unknown in Hollywood. Producers also were concerned that he was significantly older than most of his costars. Tatum credits Bynes with helping him launch his career as an actor.
Based loosely on William Shakespeare's "Twelfth Night, or What You Will". The school is called Illyria, which is the name of the country where the play takes place. Duke Orsino's character is based on Orsino, a duke. Duke's friends are named Toby and Andrew; in the play, Toby is Olivia's uncle and Andrew is one of her suitors. However, in the play, Viola is not impersonating her brother in particular, just a man, and she calls herself Cesario, which is the name of the restaurant seen where Sebastian/Viola breaks up with Monique and where Duke, Olivia, Eunice, and Sebastian/Viola briefly double date. On Viola's first day at Illyria, she walks by a school theatre playbill entitled "What You Will."
In the double date scene, as Eunice is sitting down, Amanda Bynes ad-libs the phrase "Lady pterodactyl." In fact, most outbursts were improvised, like David Cross inviting Sebastian to "have a nice apple and sandwich."