The Chocolate War is very concerned with psychological terror. Archie and Brother Leon love messing with people's minds and are masters of psychological manipulation. They know what makes people afraid, and they know how to use this knowledge to make others do what they want. The novel traces the impact of this psychological terrorism on the students it's being practiced on.
This is perfect for a story in the Gothic genre, which usually features characters who become more and more physically and/or psychologically isolated as the story progresses. The physical and psychological violence practiced in The Chocolate War increases with every phase of the plot in The Chocolate War and drives forward the action. (Psst. If you need more info on Gothic literature, check out this University of California, Davis website, and see how many similarities you can pick out between a typical Gothic novel and The Chocolate War.)
Although some of the events in the novel might seem a bit fantastical (like the raffle at the end), Cormier makes a serious attempt to accurately portray the inner workings of the minds of the characters. Do you think the book is realistic? Are some high schools really this bad? Are the characters believable? We'll leave those questions up to you.
The Chocolate War is also a tragedy. For more on this, check out "Characters: Jerry Renault," were we discuss Jerry as a tragic hero.