Counter-spell

A Counter-spell is a type of spell where the primary effect is to inhibit, remove, or negate the effects of another spell.

Classification
Despite there not being a specified definition for a counter-spell, one would naturally assume from the name that counter-spells counter the spell type that replaces the "-spell" suffix in their name (if it does so). For example, a counter-charm should theoretically reverse a charm, a counter-curse should reverse a curse, a counter-jinx a jinx, a counter-transfiguration a transfiguration and so on. However, this theory appears to be canonically contradicted on several occasions.

For example, in their confrontation in the Chamber of Secrets, Tom Riddle asked Harry Potter how he survived the former's Killing Curse and then concluded that it was the result of Lily's Sacrificial Protection, which he mentioned was a powerful counter-charm. Similarly, in 1991, while Quirrell jinxed Harry Potter's broom, Snape was later revealed to have been muttering a counter-curse. Whilst this would suggest that counter-curse refers to a counter-spell that counter a spell of any type, this cannot be true due to the known existence of counter-jinxes.

Likewise, there is the term Untransfiguration (which reverses transfiguration) as opposed to counter-transfiguration, which would be expected. Therefore, the true counter-spell nomenclature is unknown, though (according to all canonical sources), it seems to go as such:


 * Counter-spells that act like charms (regardless of the spell type they counter and regardless of whether they prevent or remove the spell in effect) are termed counter-charms.
 * Counter-spells that act like Transfigurations are Untransfigurations.
 * A counter-spell designed to foil another offensive spell is termed either a counter-jinx, -hex or -curse depending on how strong it is (similar to the offensive spell hierarchy).
 * Counter-spell that prevent jinxes (but do not remove them) are termed anti-jinxes.

For the purposes of this wiki, broad-spectrum counter-spells (such as the widely-used Finite Incantatem, which simply terminates spell effects in general) or ones that appear to be counter-spells but are of unknown type are termed undifferentiated counter-spells.

It should be noted that the categories are not mutually exclusive either. For example, Vipera Evanesca is both a Counter-curse and untransfiguration at the same time.

Undifferentiated counter-spells

 * Finite Incantatem - Non-specific counter-spell that acts over an area to terminate spell effects in general.
 * Finite - Same as Finite Incantatem, but acts on a specified target.
 * Meteolojinx Recanto - terminates magical weather effects.

Known counter-curses

 * Counter-curse for Leg-Locker Curse
 * Counter-curse for Broom jinx
 * Liberacorpus for Levicorpus
 * Vipera Evanesca for Serpensortia

Known counter-charms

 * Banishing Charm for the Summoning Charm
 * Alohomora for Colloportus
 * An unknown charm counters Annihilare, Dunamis, Emancipare, and Liberare
 * Nox for Lumos
 * Quietus for Sonorus
 * Counter-Charm for hiccoughs
 * Sacrificial Protection for the Killing Curse

Known Untransfigurations

 * Vipera Evanesca for Serpensortia.
 * Animagus reversal spell for Animagi.
 * Pig Into Desk for Desk Into Pig.
 * Ferret to human for Human to ferret.

Behind the scenes

 * Gilderoy Lockhart claimed that he knew the Counter-Curse to prevent the Petrification, in the second film, as oposed to the Transmogrifian Torture, in the novel. Of course, due to his dishonesty, it is debatable as to whether such Counter-Curses exist in the first place, let alone whether or not he would actually know them.
 * Wilbert Slinkhard once said that the term "Counter-Jinx" was improperly named, and that "Counter-Jinx is a name wizards give their spells to make them sound more friendly". Hermione Granger disagreed with this assessment.
 * According to W.O.M.B.A.T., it may not be possible to Untransfigure a person or object without knowing what they were originally. However, in Harry Potter and the Goblet of Fire, when Draco Malfoy is turned into a ferret, Professor McGonagall Untransfigures him while only knowing that it was a student, not who it was specifically. This implies that either one does not need to know very specific details about what the object was before Transfiguration or that she guessed it was Malfoy due to his absence from his usual gang.
 * Given the nature of these spells, as well the fact that counter-jinxes have only been heard of in a Defence Against the Dark Arts textbook, it appears likely that these types of spells comprise a large part of the syllabus of that particular subject.
 * It is not known why there are specific spells to counter other spells, when one could theoretically counter any spell with a broad-spectrum one such as Finite Incantatem. It may be that certain spells have in built protections or are simply too robust for a general counter-spell to work against them and therefore might require something specifically tailored to work around their specific protections to remedy this. This should be especially true for the conjuration serpensortia, the snake produced by which was dispelled not with a simple Vanishing spell but a specific Untransfiguration and Counter-curse.
 * Since it does not appear that the categories of counter-spells are mutually exclusive (in the same way that the categories of spell types are not) it may be that all counter-spells the counter-curse, -hex, -jinx nomenclature classifies the counter-spell based on its strength and counter-charm/Untransfiguration are used to refer to its M.O.
 * Similarly, there may be an identical series of counter-spell labels for counter-spells that prevent certain magics, e.g. anti-jinxes, anti-hexes, anti-charms etc.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Prisoner of Azkaban
 * 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 Goblet of Fire (film)
 * Harry Potter and the Goblet of Fire (video game)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part 2
 * Harry Potter and the Deathly Hallows: Part 2 (video game)
 * Pottermore