Knockback Jinx

"The incantation for the knockback jinx is 'Flipendo' .This jinx is the most utilitarian of Grade 2 spell, in that it will allow the caster to 'knock back' an opponent or object and can also be used to push and activate certain magically charmed switches. Like many Grade 2 spells, Flipendo can be targeted."

- The Standard Book of Spells, Grade 2

The Knockback Jinx (Flipendo  ) is a jinx that can be used to physically repel an opponent, knock away an object, blast apart fragile objects and active magically charmed switches.

It is covered in both Quentin Trimble's The Dark Forces: A Guide to Self-Protection and Miranda Goshawk's ''The Standard Book of Spells, Grade 2.

History
This jinx was taught by Professor Quirinus Quirrell to his first year class in 1991; they later used it to defeat the various imps, fire crabs, and pixies residing in Hogwarts Castle, as well as helping to protect themselves against the monsters in the Forbidden Forest.

In the second year, students learn how to charge up the spell to more powerful levels (without casting the variations). To do so, one must hold their power in their wand and release their magic when the blue spell turns a strange purplish-red colour. Past this point, the spell will backfire in mid-cast, or fly back to the caster, damaging them somewhat.

Effect
The Knockback Jinx feels like a blow to the chest, knocking its victim back, along with "a loud bang."

Defence
The Knockback Jinx can be rebounded to its caster by means of the Shield Charm, as many other spells can, or simply dodged.

Known uses
"There was a loud bang and he felt himself flying backwards as if punched; as he slammed into the kitchen wall and slid to the floor, he glimpsed the tail of Lupin's cloak disappearing round the door."

- Lupin uses this on Harry.

Behind the scenes

 * This jinx can be bought at Wiseacre's Wizarding Equipment in Diagon Alley.
 * In the films, Everte Statum and Rictusempra are used instead.
 * Every time Harry had this jinx used on him, it was because he had called the caster a coward.
 * A spellbook detailing how to cast this spell could be found in Ollivanders Wand Shop.
 * In the Harry Potter and the Philosopher's Stone (video game) Harry can cast this spell on Flipendo Buttons to activate certain mechanisms such as lifting a portcullis or moving flying platforms.
 * In the film adaptations, Stupefy seems to have the same effects of Flipendo.

Appearances

 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Prisoner of Azkaban (video game)
 * Harry Potter and the Goblet of Fire (video game)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows
 * LEGO Harry Potter: Years 1-4
 * LEGO Harry Potter: Years 5-7
 * Pottermore 
 * Harry Potter Trading Card Game

Notes and references
Maleficio rechazo Sortilège du Repoustout Flipendo