In the Wizarding World, a password is a secret word or phrase used to gain entry to a magically protected or concealed area. This form of security is most prominently used at Hogwarts School of Witchcraft and Wizardry to guard the entrances to the four House common rooms and other restricted locations like the Headmaster's office. The system typically requires an individual to speak the correct password to a magical guardian, such as a sentient portrait (like the Fat Lady or the portrait of Salazar Slytherin) or an enchanted gargoyle. If the correct password is given, the guardian will permit entry by swinging aside or revealing a hidden entrance. If an incorrect password is given, or if the individual does not know the password, access is denied. Passwords are changed frequently to maintain security. New passwords are often posted on the House notice boards or communicated to the students by a Head of House or a Prefect. The nature of the passwords can vary greatly, from Latin phrases and obscure magical terms to seemingly nonsensical or mundane words.
The following is a list of passwords used throughout the original novels, organized by location.
Guarded by the Fat Lady, the Gryffindor passwords were changed numerous times.
The entrance to the Slytherin Common Room is a bare stretch of stone wall in the dungeons.
The entrance is guarded by a large stone gargoyle that springs to life and moves aside when given the correct password.
Located on the fifth floor, the door to this bathroom has no handle and will only open when given the correct password.
Passwords serve several key functions in the narrative. Primarily, they are a world-building element that establishes the magical customs and daily security measures within Hogwarts. They create a sense of belonging and exclusivity for each House. On a plot level, passwords act as minor but recurring obstacles. Neville Longbottom's chronic forgetfulness of passwords provides comic relief and characterizes his absent-minded nature. This trait becomes a major plot point when his list of passwords allows Sirius Black to enter Gryffindor Tower, leading to Ron Weasley being attacked and escalating the hunt for Black within the castle. The need to discover a password can also drive the plot forward. Harry and Ron's infiltration of the Slytherin common room is entirely dependent on tricking Draco Malfoy into revealing the password. Later, Harry's need to access the Headmaster's office forces him to guess passwords, revealing something about Albus Dumbledore's personality or the current situation at the school.