Knockback Jinx

"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.

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 in which it is described as 'most utilitarian'.

The Knockback Jinx can be rebounded to its caster by means of either the Disarming Charm or the Shield Charm, the former being a much more common means of defence, as taught by Defence Against the Dark Arts teacher Professor Gilderoy Lockhart.

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.

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.

Professor Gilderoy Lockhart revised this with his second year class in the 1992-1993 school year for use in duelling. He then had Harry Potter and Draco Malfoy duel each other with it, the winner earning fifty points for their house

In June of 1997, Professor Severus Snape used this jinx on Harry Potter when escaping Hogwarts Castle alongside the Death Eaters.

On 1 September, 1997, Harry had this spell used on him once more, this time by Remus Lupin at 12 Grimmauld Place.

Practitioners

 * Dobby the House Elf
 * Draco Malfoy
 * Garrick Ollivander
 * Harry Potter
 * Hermione Granger
 * Quirinus Quirrell
 * Remus Lupin
 * Ronald Weasley
 * Severus Snape

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 had called the caster a coward.
 * A spellbook detailing how to cast this spell could be found in Ollivanders Wand Shop.

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