Stunning Spell

• Incantation: Stupefy
• Pronunciation: STOO-puh-fye
• Wand Movement: Not specified in the novels.
• Light: A jet of brilliant red light.
• Effect: Renders a living target unconscious. The Stunning Spell, also known as a Stunner or Stunning Charm, is a common and highly practical spell in duelling and combat. It can also be used to stop moving objects in their tracks. While a single spell is usually sufficient to incapacitate a human, more powerful creatures like dragons or giants require multiple simultaneous spells to be taken down. A person hit by several Stunners at once can suffer serious harm.
• Type: Charm

The Stunning Spell is one of the most frequently used spells throughout the series, especially in combat situations.

• In 1994, during the aftermath of the Death Eater riot at the Quidditch World Cup, multiple Ministry of Magic wizards, including Arthur Weasley and Amos Diggory, simultaneously cast Stunners on Harry Potter, Ron Weasley, and Hermione Granger in a moment of panic. Later that year, dragon handlers used Stunning Spells to control the nesting mother dragons for the First Task of the Triwizard Tournament. During the Third Task, Harry successfully used the spell on a Blast-Ended Skrewt and attempted to use it on Viktor Krum, who was under the Imperius Curse. Albus Dumbledore later used it to incapacitate Barty Crouch Jr..
• In the 1995-1996 school year, the Stunning Spell was a core part of the defensive magic curriculum taught by Harry in Dumbledore's Army.
• During the Battle of the Department of Mysteries, the spell was used extensively by members of Dumbledore's Army and Death Eaters alike.
• When Death Eaters invaded Hogwarts in 1997 during the Battle of the Astronomy Tower, Stunners were widely used. Later that year, Harry, Ron, and Hermione used the spell to escape from Death Eaters in a café on Tottenham Court Road. Harry notably stunned both Antonin Dolohov and Thorfinn Rowle.
• The spell saw its most extensive use during the Battle of Hogwarts, where it was employed by nearly every combatant on both sides as a primary offensive and defensive measure. Minerva McGonagall notably used it against the Carrows in Ravenclaw Tower.

The Stunning Spell is considered fundamental defensive magic, likely taught to students around their fourth or fifth year in preparation for their O.W.L. examinations. Harry taught it to members of Dumbledore's Army, many of whom successfully mastered it.

• Counter-Spell: The primary counter-spell is Rennervate. When cast on a stunned individual, it revives them.
• Defence: A Shield Charm (Protego) can successfully block a Stunning Spell.

The incantation, Stupefy, is derived directly from the English word “stupefy,” which means to make someone unable to think or feel properly, or to daze and bewilder them. The word itself originates from the Latin stupeō, meaning “to be stunned, numbed, or amazed.”

• In the film adaptations, the Stunning Spell is consistently shown as a jet of red light that often throws its target backward with considerable force. This physical propulsion is less emphasized in the novels, where the primary effect is immediate unconsciousness. (film)
• On the Pottermore website, the Stunning Spell is described as a “dueller's classic” and a fundamental tool in any wizard's defensive arsenal. (Pottermore)