In the Potterverse, it seems that there is a spell for everything; ranging from jinxes that prevent intruders from entering a property to healing spells that clear the throat of a choking victim. So great is the range of spells in the magical world that the only tools young witches and wizards need to survive is a wand, along with their knowledge of magic.
While most spells are used for the benefit of others and the greater good, there are those spells that are used to harm one's enemies. With so many Death Eaters and other dark characters appearing throughout the Harry Potter series, such spells are not uncommon. Let's take a look at the deadliest of these dark jinxes.
While this is a commonly-used spell throughout the Harry Potter film and book series, it remains a crucial duelling spell for any witch or wizard to learn. This spell, when cast correctly, renders an opponent unconscious without causing lasting damage.
It is commonly used amongst Aurors (otherwise known as dark wizard hunters), due to the prohibition against the use of any of the three Unforgivable Curses. Examples of its use can be seen throughout Harry Potter and the Order of the Phoenix, particularly when members of the Order battled against the Death Eaters in the Department of Mysteries during their rescue of Harry and his friends.
9 Petrificus Totalus
Yet another familiar curse, particularly to those who adore the earlier stages of the Harry Potter story. This is a body binding curse which, upon incantation, will freeze the entire body of its target. Immediately after execution, the victim's arms and legs will slap together while their body thumps to the ground.
In Harry Potter and the Sorcerer's Stone, Hermione used this spell on Neville Longbottom when he attempted to prevent Harry, Ron, and Hermione from leaving the Gryffindor Common Room. This was yet another display of Hermione's magical prowess, considering that she was only in her first year when successfully performing it.
The Legilimency spell allows the user to delve into the mind of their target, thus allowing them to read their thoughts, decipher their emotions and experience their memories. Among more powerful wizards, this spell can be used to create visions in the minds of their victims and even control their actions.
Voldemort used this extensively on Harry, even coaxing him to the Department of Mysteries with visions of Sirius, while Queenie Goldstein from the Fantastic Beasts series was born a Legilimens, meaning that she was able to understand the thoughts of others without first learning the skill. Fortunately, she used this skill for good, rather than with malicious intent.
Commonly known as "The Blasting Curse", this spell causes the intended target to explode when cast properly. To add even more danger to this spell, it produces flames that ignite upon coming into contact with the selected target.
This spell is occasionally used in duelling, but must be handled properly in order to avoid fatalities. Fans of the movies will remember how Hermione used this spell to subdue Nagini when she attacked Harry in Godric's Hollow.
This severing charm is used to cut objects with incredible accuracy. Its previous uses include Hermione using it to remove bindings from Ron after the café duel with Dolohov and Rowle, Ron severing the laces from the sleeves of his Yule Ball dress robes and Harry attempting to destroy the locket Horcrux with it, unfortunately to no avail.
While typically used to cut inanimate objects, this spell can also cut through humans, potentially severing limbs or worse, hence why it poses so much danger. Even Hermione cut Ron slightly when releasing him from his bindings after the café brawl.
The Imperius Curse is one of the three infamous Unforgivable Curses. When cast, it puts the victim under complete control of the caster. Interestingly enough, this is the only Unforgivable Curse that can be resisted, though only a witch or wizard of exceptional power may be able to do so.
Death Eaters have been known to use this curse in both Wizarding Wars. One of the key instances of this was Corban Yaxley's use of the spell on Pius Thicknesse when he became Minister of Magic, thus essentially putting the Death Eaters in charge of the wizarding world.
A little-known spell, Harry came across Sectumsempra while reading through the Potions textbook belonging to the Half-Blood Prince during his sixth year at Hogwarts. Without knowing its effects, Harry considered attempting it numerous times throughout the year, before eventually using it in a duel with Malfoy, with disastrous consequences.
When the spell hit Malfoy, it lacerated his entire body, leaving him with multiple serious wounds that were oozing blood. With Harry left standing in disbelief as to what had happened, Severus Snape hurriedly attended to Malfoy's wounds. The professor too was astonished, particularly since someone had learned the magic that he himself created.
Another of the three Unforgivable Curses, this spell causes excruciating pain for its victim; so intense that it affects their entire body. While not inflicting lasting physical harm on the victim, this spell stimulates the body's pain receptors to an extreme extent.
In the most notorious move of her criminal career, Bellatrix Lestrange used this spell to torture Frank and Alice Longbottom (parents of Neville Longbottom) into insanity. Both Harry and Hermione would later fall victim to this horrific curse themselves, at the hands of Voldemort and Bellatrix respectively.
This terrifying use of magic is so advanced that, when Crabbe conjured this spell during the events of Harry Potter and the Deathly Hallows, even Harry had never seen it before. Hermione had knowledge of it, though, because she's Hermione.
Once unleashed, the flames are almost impossible to control, which is potentially why Vincent Crabbe lost his life after conjuring this spell (a fate that instead befell Gregory Goyle in the movie). Interestingly enough, this spell is capable of destroying a Horcrux, though Hermione chose never to cast it due to the high risk associated with doing so.
1 Avada Kedavra
The last of the Unforgivable Curses (and the most feared), this formidable spell emits a flash of green light and immediately kills the intended target without leaving a trace of evidence. This curse was regularly used by Voldemort and his followers on numerous well-known victims, including Lily and James Potter, Cedric Diggory, Alastor Moody, Griphook, Rufus Scrimgeour, Gellert Grindleward and even his own parents.
Interestingly enough, during the First Wizarding War, Minister of Magical Law Enforcement Barty Crouch Sr. legalized the curse temporarily, as a desperate measure in order to win the war against the ruthless Death Eaters.