When Dolores Umbridge decided that no defensive spells would be taught to Hogwarts students, she accidentally did something wonderful. She united some of the bravest students in secret protest.

Harry and Dumbledore's Army in the Room of Requirement
Harry Potter and the Order of the Phoenix

Harry, Hermione and Ron started Dumbledore’s Army. They met in the Room of Requirement, where Harry taught them everything he’d learned from his experiences facing dragons, Dementors, Death Eaters and the Dark Lord himself.

Here are some of those spells, to help jog your imagination the next time you daydream about joining Dumbledore’s Army...

Expelliarmus

Almost beautiful in its simplicity, the Disarming Charm is frequently used in wizarding duels, forcing one’s opponent to drop their wand.

As soon as a wizard casts this charm by bellowing ‘Expelliarmus’, a jet of red light shoots from their wand. Harry has the members of Dumbledore’s Army practise the spell in pairs.

Stupefy

Stunning is one of the most useful spells in the wizard’s arsenal. It renders the victim unconscious.

The effects of the Stunning Spell may be counteracted by ‘Rennervate’, but will also wear off with time on their own. Another method of avoiding the spell is to deflect it with a Shield Charm, which Harry does teach his D.A. comrades.

Levicorpus

In the film Order of the Phoenix members of Dumbledore’s Army practise the spell on each other in the Room of Requirement under Harry’s supervision, and Luna Lovegood goes on to use this one on a Death Eater in the Ministry of Magic.

The incantation ‘Levicorpus’ can be cast silently or spoken aloud, resulting in the victim being suspended in mid-air by their ankle. There is a counter jinx, called ‘Liberacorpus’.

Dumbledore's Army battling the Death Eaters in the Room of Prophecy
Harry Potter and the Order of the Phoenix

Reducto

This spell splits a solid object into pieces or even into a fine dust. Members of Dumbledore’s Army then proceed to use the curse during the Battle of the Department of Mysteries, smashing the shelves in the Hall of Prophecy.

Expecto Patronum

The Patronus Charm is the most difficult spell Harry attempts to teach Dumbledore’s Army. Many witches and wizards are unable to produce a Patronus at all.

Remus Lupin originally taught Harry how to master this tricky charm when Harry needed it to protect himself from the Dementors who were paying him unwelcome attention. The charm requires the incantation ‘Expecto Patronum’ combined with intense concentration on a single, extremely happy memory. The Patronus then acts as a shield, with Dementors feeding on it rather than the wizard himself.

Harry’s Patronus takes the form of a stag (his father’s Animagus), Hermione’s is an otter, Ron’s is a Jack Russell terrier, Luna Lovegood’s is a hare, Ginny Weasley’s is a horse and Cho Chang’s is a swan.

Harry teaches the charm to Dumbledore’s Army for the purpose of protection from Dark creatures like Dementors, but the spell also has another use, devised by Dumbledore. He invented a way of using the Patronus to deliver messages, a tool both he and members of the Order of the Phoenix utilise for secure communication.