Blackboard

• Type: Classroom Furnishing, Magical Device
• Owners: Hogwarts School of Witchcraft and Wizardry
• Maker: Unknown

A blackboard in the Wizarding World is a large, reusable writing surface, typically black or dark green, mounted on the wall of a classroom. Physically, it appears identical to a standard Muggle blackboard and is used with chalk. They are a ubiquitous feature in most Hogwarts classrooms, including Potions, Transfiguration, and Defence Against the Dark Arts.

Unlike their mundane counterparts, blackboards within Hogwarts are frequently enchanted to operate magically. The most common magical property is their ability to be self-writing. A professor can, with a simple flick or tap of their wand, cause words, sentences, diagrams, and even moving images to appear on the board's surface without physically writing. This magical function allows for the efficient delivery of lesson material, from simple course aims to complex instructions and historical narratives. The magic animates the chalk to write clearly and quickly, serving as a fundamental tool for teaching at Hogwarts.

Throughout Harry Potter's time at Hogwarts, magical blackboards are used in numerous lessons:

1. In Harry's first Potions lesson, Professor Snape uses his wand to make the instructions for a Boil-Curing Potion appear on the blackboard.
2. In his second year, Professor McGonagall uses the Transfiguration classroom's blackboard to write out the legend of the Chamber of Secrets for her students.
3. Barty Crouch Jr., disguised as Professor Moody, writes the names of the three Unforgivable Curses on the blackboard before demonstrating them to his fourth-year Defence Against the Dark Arts class.
4. Dolores Umbridge, upon taking over Defence Against the Dark Arts, magically writes her restrictive “Course Aims” on the blackboard by simply tapping it with her wand.
5. As the Defence Against the Dark Arts teacher in Harry's sixth year, Professor Snape uses the blackboard to discuss Non-verbal spells and to display a frightening, moving picture of an Inferius.

The magical blackboard primarily serves as a narrative device for exposition, efficiently conveying crucial information to both the characters and the reader. It is often through the text that appears on a blackboard that key plot points, magical concepts, and historical lore are introduced. Beyond exposition, the use of the blackboard often reflects the personality and teaching style of the professor. Professor Snape's abrupt use of it demonstrates his efficiency and impatience, while Dolores Umbridge's magically appearing list of rules establishes her authoritarian control from her very first lesson. The information revealed on the blackboard, such as the Unforgivable Curses or the story of the Chamber of Secrets, is often pivotal to the plot of a particular book.

In the Harry Potter film series, the self-writing blackboard is a frequently used visual effect. The sight of chalk moving on its own to form words is a memorable piece of magic that visually establishes the magical nature of a Hogwarts education. (film)