- "'R-r-riddikulus!' squeaked Neville. There was a noise like a whip-crack."
- —Neville Longbottom casts this spell[src]
The Boggart-Banishing Spell (Riddikulus) is a charm that is used in defence against a Boggart. It causes the creature to assume a form that is humorous to the caster, along with a whip-crack noise, thereby counteracting the Boggart's ability to terrorise.
Boggarts are defeated by laughter, so forcing them to assume an amusing form is the first step to defeating them. However, because Boggarts are amortal, this spell does not truly destroy them, similar to the Patronus Charm, but merely "banish" them — meaning the defeated Boggart will appear to vanish, and presumably rematerialize elsewhere.
A simple charm that requires force of mind, to cast, the spell caster must first acknowledge what they fear the most (as it will most likely be what the Boggart will take the form of) and then visualise it into something amusing. The problem is, because the Boggart would have assumed said form at the moment of direct encounter, the one attempting to use this charm would have lost concentration after seeing the Boggart manifest their worst fears, making this spell useless. As such, it is always advisable to first take one step at a time when practising this enchantment.
|Third years||June 1994||The third year Defence Against the Dark Arts exam was an obstacle course of dark creatures which included; climbing into an old trunk and battling a boggart.|
|Harry Potter||24 June, 1995||Harry used this against a boggart in the maze during the Triwizard Tournament.|
|June 1996||Harry did a perfect one during the practical part of his Defence Against the Dark Arts O.W.L.|
|Molly Weasley||August 1995||Molly tried and failed to use this spell against the boggart at number twelve, Grimmauld Place.|
"Riddikulus" is an adaptation of "ridiculous" as well as of ridiculum (Latin, "joke") and ridere (Latin, "to laugh").
Behind the scenes
- The effect of the Boggart-Banishing Spell varies throughout the series. In Harry Potter and the Prisoner of Azkaban, it has its stated effect of forcing a Boggart into an amusing form and otherwise does not harm it. In Harry Potter and the Goblet of Fire, however, Harry uses the spell to make a Boggart-Dementor explode into a wisp of smoke (though it is possible he found a Dementor collapsing into wisps of smoke "funny", and the Boggart was forced to take the form of an exploded Dementor, more than it actually exploded in earnest). Various anecdotes on Pottermore describe Riddikulus transforming Boggarts in a variety of ways, not all of which being directly related to making the Boggart funny.
- The wand movement given for the Boggart-Banishing Spell resembles a large grin, likely on purpose.
- In LEGO Harry Potter: Years 1-4, only Ron and Hermione learn this spell due to Harry being locked out of the class while Lupin is teaching it to his class. Harry instead learns Expecto Patronum from Lupin to defeat his Dementor boggart, and in return Ron and Hermione do not learn Expecto Patronum.
- In LEGO Dimensions, Riddikulus is one of Hermione's abilities, though it does nothing more than break nearby objects and damage nearby enemies.
- Harry Potter and the Prisoner of Azkaban (First appearance)
- Harry Potter and the Prisoner of Azkaban (film)
- Harry Potter and the Prisoner of Azkaban (video game)
- Harry Potter and the Goblet of Fire
- Harry Potter and the Order of the Phoenix
- LEGO Harry Potter: Building the Magical World (Mentioned only)
- LEGO Harry Potter: Years 1-4
- LEGO Dimensions
- Harry Potter: The Character Vault
- Harry Potter: The Creature Vault
- Harry Potter: Hogwarts Mystery
- Fantastic Beasts: The Crimes of Grindelwald