Decree for the Reasonable Restriction of Underage Sorcery

"Dear Mr Potter,
We have received intelligence that you performed the Patronus Charm at twenty-three minutes past nine this evening in a Muggle-inhabited area and in the presence of a Muggle."

— Mafalda Hopkirk's letter adressed to Harry Potter on 2 August 1995

Mafalda Hopkirk's letter warning Harry Potter about his breach of the Decree

The Decree for the Reasonable Restriction of Underage Sorcery was a bylaw of the British Ministry of Magic, written in 1875, which banned the use of underage magic outside of school.

The Decree was enforced by the Improper Use of Magic Office in the Ministry of Magic. The restriction was for wizards and witches who were under the age of seventeen, upon which the Trace still operated. Even so, the Ministry did recognise that they might have to use magic in certain situations such as self-defence in a life-threatening situation.

In addition, young children below school age, or children who were not in possession of a wand, were mostly exempt from the rule since they usually had little or no control over the magic they performed. Overall, it appeared that the Ministry of Magic generally limited enforcement of the decree to situations where underage wizards performed magic in front of Muggles.

Known contents

"In the matter of Harry Potter, the law clearly states that magic can be used before Muggles in life-threatening situations."

— Albus Dumbledore at Harry Potter's hearing

Paragraph C of the clause stated that it was a crime to knowingly perform magic in a Muggle-inhabited area and in the presence of a Muggle. However, Clause 7 also stated that magic could be used in front of Muggles in exceptional circumstances, including situations when the life of the witch or wizard using the spell, or the lives of other witches, wizards and Muggles were threatened.

It seemed that a high-authority person might give permission for an underage student to perform magic under circumstances; as Hogwarts Headmaster, Albus Dumbledore gave Harry Potter such an instruction if an attack was to eventuate, when he was 16 years old. Also, if an underage student unintentionally performed magic out of emotional stress, the Ministry might consider this to be accidental magic, and not punish said student, as Dumbledore noted that even the best of adult wizards couldn't always control their emotions, and Fudge did somewhat take this into account when he spoke to Harry about it.

The use of objects already enchanted by someone else did not count as a violation, as stated by Ronald Weasley, at that time aged 12, when he and his brothers Fred and George, aged 14, used their father's flying Ford Anglia during the summer holidays.

Known breaches

Ron Weasley: "We can fly the car to Hogwarts!"

Harry Potter: "But I thought –"

Ron Weasley: "We're stuck, right? And we've got to get to school, haven't we? And even underage wizards are allowed to use magic if it's a real emergency, section nineteen or something of the Restriction of Thingy ..."

— Harry Potter and Ron Weasley while stuck at the barrier to Platform 9¾

Offender	Crime	Date	Action taken	Notes
Lily Evans	Magic	Between 1971 and early January 1977	Received a few warning letters	None of her warning letters were "too serious".
Harry Potter	Illegal use of a Hover Charm	31 July 1992	Official warning	The Hover Charm was actually produced by the house-elf Dobby.
	Illegal use of the Inflating Charm on Marjorie Dursley	6 August 1993	No action taken	Action not taken due to the recent escape of Sirius Black from Azkaban, and the need to keep Harry safe. Additionally, this was considered "accidental magic".
	Illegal use of the Patronus Charm in front of a Muggle	2 August, 1995	Once notified expulsion from Hogwarts, later rescinded and given a hearing	Acquitted of all charges due to the fact that he technically did not break any laws. Dolores Umbridge was the one who secretly orchestrated this incident as part of the smear campaign against Harry.

Undetected/ignored breaches

• Hermione Granger told Harry Potter and Ron Weasley just prior to their first year at Hogwarts that she had successfully cast a few spells, but apparently, she received no notice or warning about this being banned.
• Harry Potter performed the Wand-Lighting Charm shortly after his illegal usage of the Patronus Charm and letter, it did not add to his offence.
• Tom Riddle, at age 16 during his summer vacation, used the Stunning Spell to incapacitate his maternal uncle, and then took his wand for multitude of uses: the Unlocking Charm to break into the Riddle House, the Killing Curse to murder his paternal family, and then to implant a false memory into his uncle to frame him. The Ministry never even took Tom into account for the multiple breaches, let alone the crimes, as his uncle was in the vicinity, who instead became the suspect for every piece of magic performed.
• Bellatrix Lestrange trained her nephew Draco Malfoy in various fields of magic, which would most likely require Draco himself to use magic, during his summer vacation at age 16. Due to Draco being raised in a magical household, with both his mother and aunt being adult witches (albeit the latter being a wanted criminal), Draco's breaches could not be detected.
• When Harry Potter was caught in the Battle of the Seven Potters, he used several spells to retaliate against the Death Eaters, such as the Disarming and Mending Charms. The Ministry ignored this breach due to wanting to keep the Azkaban breakout a secret. However, this may be because the Ministry was currently assisting Harry Potter, and recognised that they were in a life-threatening situation, as well as the fact that the Ministry was not completely under Voldemort's regime at the time.
• Before Sirius Black defected from his family at age 16, he used the Permanent Sticking Charm to stick some muggle pictures of girls in his room. His breach was not detected due to his household being a magical family.

Behind the scenes

• In the film adaptation of Harry Potter and the Chamber of Secrets, it is Hermione Granger who magically repairs Harry's glasses at Diagon Alley, not Arthur Weasley, which should be a violation of this decree. However, because the only Muggles around were those aware of the Magical community and she was accompanied by parents, Hermione was not punished.
• In the film adaptation of Harry Potter and the Chamber of Secrets, Harry did not receive a warning for the illegal use of a Hover Charm which caused a continuity error in the following films due to the fact that the book version caused the Dursley family to learn that Harry cannot use magic outside of school.
• The film version of Harry Potter and the Prisoner of Azkaban has Harry using the spell Lumos Maxima and yet receiving no warning. It is also possible Lumos Maxima was considered too mundane to be monitored; moreover, it was not performed in front of Muggles.
• In the film adaptation of Harry Potter and the Order of the Phoenix, Umbridge's involvement in the Dementor attack on Harry Potter and Dudley Dursley was omitted. As a result, the one behind the attack was never identified in the film.
• In the film adaptation of Harry Potter and the Order of the Phoenix, when Dumbledore brought up Clause 7 as a justifiable defence for Harry's breach of the decree, Cornelius Fudge immediately and directly countered that "laws can be changed if necessary", suggesting that he intended to make it illegal for underage wizards and witches to use magic at all, even if was to save lives.
• It's unknown how magic is restricted for those wizards who are home-schooled. It is possible that they are only allowed to use magic at their home, or only when their private teacher is present. Albus Dumbledore also allowed Harry Potter to perform magic in summer 1996 when he accompanied him to find Horace Slughorn.
• It is unclear why Paragraph C specifically prohibits using magic in the presence of Muggles and Clause 7 specifically permits using magic before Muggles in certain circumstances; using magic before Muggles seems to be far more in the purview of the International Statute of Wizarding Secrecy than this decree.

Appearances

• Harry Potter and the Chamber of Secrets (First appearance)
• Harry Potter and the Chamber of Secrets (film) (Mentioned only)
• Harry Potter and the Prisoner of Azkaban (Mentioned only)
• Harry Potter and the Prisoner of Azkaban (film) (Mentioned only)
• Harry Potter and the Order of the Phoenix
• Harry Potter and the Order of the Phoenix (film)
• The Tales of Beedle the Bard (explained by Albus Dumbledore in a footnote)