Defence Against the Dark Arts (D.A.D.A.)

Defence Against the Dark Arts, commonly abbreviated as D.A.D.A., is a core subject taught at Hogwarts School of Witchcraft and Wizardry. The class is dedicated to instructing young witches and wizards on how to protect themselves from the Dark Arts. This includes learning to defend against Dark creatures, Dark Magic, and offensive spells used by other magic-users. For much of the series, the teaching post for this subject was infamously considered jinxed, as no professor managed to hold the position for more than a single school year.

The Defence Against the Dark Arts teaching post was cursed by Lord Voldemort after he, as a young Tom Riddle, was denied the position twice by Headmaster Albus Dumbledore. The first time was shortly after his own graduation, and the second was several years later when he returned to Hogwarts to hide the Diadem of Ravenclaw Horcrux. As a result of this jinx, no teacher after the curse was implemented held the post for longer than one year. Each of Harry Potter's professors met with a different misfortune that led to their departure, ranging from death and memory loss to exposure and dismissal. Dumbledore confirmed his suspicions about the jinx to Harry in 1996. The jinx was permanently broken with the death of Lord Voldemort.

A chronological list of the known teachers for Defence Against the Dark Arts.

• Galatea Merrythought (c. 1895 - 1945): Taught at Hogwarts for fifty years, including instructing a young Tom Riddle. She retired in 1945, and Riddle first applied to take her place.
• Quirinus Quirrell (1991-1992): A formerly brilliant but timid wizard who, after an encounter with Lord Voldemort, began to serve him. He secretly shared his body with Voldemort's disembodied spirit throughout the school year. He died in the Underground Chambers when the sacrificial protection left on Harry Potter by Lily Potter caused his body to burn upon contact.
• Gilderoy Lockhart (1992-1993): A famous author and five-time winner of Witch Weekly's Most-Charming-Smile Award. Lockhart was a fraud who used the Memory Charm (Obliviate) to steal the stories of other accomplished witches and wizards. His tenure ended when a Memory Charm cast from Ron Weasley's broken wand backfired, erasing his own memory. He was subsequently institutionalized at St. Mungo's Hospital for Magical Maladies and Injuries.
• Remus Lupin (1993-1994): A kind, intelligent, and highly competent teacher who was a close friend of James Potter. He taught the students practical defence against a variety of Dark creatures, including Boggarts and Grindylows. Lupin was forced to resign after Severus Snape exposed him as a Werewolf to the school community.
• Barty Crouch Jr. (disguised as Alastor "Mad-Eye" Moody) (1994-1995): A loyal Death Eater who escaped from Azkaban. Using Polyjuice Potion, he impersonated the famous Auror Alastor Moody for the entire school year as part of Voldemort's plan to capture Harry Potter. He was exposed after the third task of the Triwizard Tournament and was subjected to the Dementor's Kiss before he could testify, rendering him without a soul.
• Dolores Umbridge (1995-1996): The Senior Undersecretary to the Minister for Magic. She was appointed by a paranoid Ministry of Magic to control Hogwarts. Her curriculum was purely theoretical and forbade the practice of defensive spells, which led Harry, Ron Weasley, and Hermione Granger to form Dumbledore's Army. She was removed from her post after being carried away by a herd of Centaurs in the Forbidden Forest.
• Severus Snape (1996-1997): After years of petitioning for the job, the Potions Master was finally appointed Defence Against the Dark Arts professor. His lessons focused heavily on the Dark Arts themselves, Non-verbal spells, and his personal animosity towards Harry Potter. He abandoned the position at the end of the year after killing Albus Dumbledore and fleeing Hogwarts.
• Amycus Carrow (1997-1998): A brutal Death Eater appointed to the staff during Voldemort's control of Hogwarts. Under his tenure, the class was renamed simply “Dark Arts,” and students were taught to perform curses like the Cruciatus Curse rather than defend against them. He was incapacitated by Harry Potter and Minerva McGonagall in Ravenclaw Tower just before the Battle of Hogwarts.

The D.A.D.A. curriculum covered a wide range of topics essential for a wizard's self-protection. Students learned specific defensive spells such as the Disarming Charm (Expelliarmus), the Shield Charm (Protego), and how to produce a Patronus. They also studied Dark creatures and how to repel them, including Boggarts, Red Caps, Kappas, Grindylows, Hinkypunks, and Werewolves. The subject was a required class for the first five years and was tested at both O.W.L. and N.E.W.T. levels. The Defence Against the Dark Arts classroom is located on the first floor of Hogwarts Castle. The room's decor changed dramatically with each new professor, often reflecting their personality or teaching focus. For example, under Gilderoy Lockhart, the room was filled with portraits of himself. Remus Lupin brought in tanks containing various Dark creatures for practical lessons. When Barty Crouch Jr. (as Moody) taught, the room contained instruments like a Foe-Glass and Secrecy Sensors. Under Dolores Umbridge, the room became sickeningly pink and was decorated with plates featuring moving kittens.

• J.K. Rowling has stated that the constant rotation of Defence Against the Dark Arts teachers was a useful plot device, allowing her to introduce a new, important character each year with their own agenda and impact on Harry's story (J.K. Rowling interview).
• After the Second Wizarding War, the jinx on the D.A.D.A. position was broken. A permanent, unnamed professor was eventually appointed to the post (J.K. Rowling interview).
• In the films, the D.A.D.A. classroom is depicted as a large, ornate room with a moving dragon skeleton hanging from the ceiling, which does not change significantly between teachers (film).