The plot of Jason and Marceline is basically episodic; that is, it consists of what is really a series of short stories without too much unity between them except that all are episodes in the ninth grade life of Jason Herkimer. In the course of the novel, Jason, the narrator, matures, even though in many of the individual episodes he seems very immature.

Although Jason and Marceline is not as accomplished a novel as Spinelli's Newbery Award-wining book, Maniac Magee, it is still enjoyable to read, especially because of its humor. It is written in language fairly simple to understand, the kind of language a boy like Jason would use, and it uses the kind of language that a ninthgrader would employ, including slang.

Because of this, several reviewers of Jason and Marceline call the book "crude," and at least one writes of its "locker-room talk...