Defense Against The Dark Arts

Defence Against the Dark Arts (sometimes written as DADA) is a mandatory subject taught at Hogwarts School of Witchcraft and Wizardry in which students learn how to magically defend themselves against Dark Creatures and the Dark Arts.
The curriculum of the class varies greatly depending on what the professor at the time deems appropriate; due to the jinx on the teaching post, a great many teachers have been appointed.
The class is mandatory from the first year until the fifth year, with the option of NEWT classes for those who qualify. 

Due to the constant changing of teachers, the curriculum of Defence Against the Dark Arts varies from year to year. Each teacher has their own priorities, their respective efficiencies proportional to their beliefs and methods. Such as Quirinus Quirrell and Dolores Umbridge believing that theories are enough (which is, in fact, more hindering), while the more effective Remus Lupin, "Alastor Moody" and Severus Snape have a more balanced belief in theory and practical defence. Gilderoy Lockhart, fraudulent and incompetent, is one known teacher who has taught nothing to the classes of his respective tenure, aside from nonsensical and unrelated materials. In the 1997-1998 school year, the class was changed to Dark Arts.