The defense classroom was located on the third floor in a circular tower. There were arched windows with thick, bubbled glass and stone walls that were lined with bookshelves and odd instruments. An iron chandelier hung down from the ceiling, while a large mahogany desk and a worn carpet marked the center of the room. A large stone fireplace added to the cozy atmosphere.

The aim of the course is to teach students how to protect themselves against the dark and potentially harmful forces that exist in the wizarding world. This includes teaching students defensive spells, identifying and understanding various magical creatures, learning about cursed and prohibited objects, and understanding the principles of counter charms and curses. The course also covers the history and theories behind the dark arts, as well as the ethical considerations involved in using magic for defensive purposes.