Restricted Section

• Type: Library Section
• Location: Hogwarts Library, Hogwarts Castle, Scotland
• Owner/Residents: Hogwarts School of Witchcraft and Wizardry; overseen by the current librarian, Madam Pince
• Key Features: Contains books on the Dark Arts and other forms of powerful or dangerous magic; requires a signed permission slip from a professor for access; protected by enchantments and contains books that may be dangerous in themselves.

The Restricted Section is a specific, roped-off area within the main Hogwarts Library that houses books on subjects generally forbidden to students. Access is strictly controlled by the school's librarian, Madam Pince, who requires a signed note from a teacher specifying a valid reason for a student to consult a text from this section. The books stored here have a “faintly sinister look” and cover topics considered dangerous, dark, or simply too advanced for the standard Hogwarts curriculum. These subjects include the Dark Arts, potent and complex Potions, and advanced Transfiguration. The books themselves are often enchanted for security; one book, when opened by Harry Potter, let out a “piercing, bloodcurdling shriek”. The primary purpose of the Restricted Section is to act as a secure repository for dangerous knowledge, preventing students from casually experimenting with magic that could cause great harm to themselves or others. It ensures that such information is only accessible under the direct supervision and approval of a qualified member of the Hogwarts staff.

The Restricted Section plays a pivotal role at several key points in the series, serving as the source of crucial, otherwise unobtainable information for Harry Potter and his friends.

• In Harry Potter and the Philosopher's Stone, Hermione Granger is the first of the trio to gain legitimate access. She obtains a permission slip from Professor Flitwick to borrow Moste Potente Potions, under the pretext of being interested in its relation to the Lifting Charm. This search, however, is part of their effort to identify Nicolas Flamel. Later, Harry uses his Invisibility Cloak to sneak into the section at night. During this illicit visit, he is startled by a screaming book and forced to flee from Argus Filch, leading to his first discovery of the Mirror of Erised.
• In Harry Potter and the Chamber of Secrets, Hermione once again devises a way to access the section. She flatters Professor Lockhart into signing a permission slip, allowing her to take out Moste Potente Potions. From this book, she obtains the recipe for Polyjuice Potion, which is essential to their plan to impersonate Slytherin students and investigate Draco Malfoy's connection to the Chamber of Secrets.
• In Harry Potter and the Half-Blood Prince, the section becomes critical to understanding Lord Voldemort's immortality. After Professor Slughorn avoids her questions, Hermione researches Horcruxes on her own. She uses a Summoning Charm to retrieve a book titled Magick Moste Evile from a high shelf in the Restricted Section. The book describes Horcruxes in horrifying detail, confirming Harry's suspicions and providing the trio with their first concrete knowledge of what they must hunt and destroy. A memory viewed in the Pensieve also reveals that a young Tom Riddle used the Restricted Section to first learn about Horcruxes decades earlier.

In the film adaptations, the Restricted Section is often depicted as a more visually distinct and imposing area than described in the novels. Rather than simply being roped off, it is frequently shown behind a locked gate in a darker, more cavernous part of the library, emphasizing its forbidden and dangerous nature (film). The scene of the screaming book from the first film is a particularly memorable cinematic moment.