A counterspell is a spell that is used in response to an opponent casting their spell, which prevents that spell from doing its thing. Typically, a counterspell has to be specified in the same way that the spell is, so the one casting it has to know the caster and spell that they're trying to counter. In video games with a "casting speed" mechanic, counterspells are typically cast very fast so that they can finish casting while the other guy is still casting theirs. In card games with a last-in, first-out "stack" for responding to opponents, that isn't needed.
Subtrope of Anti-Magic. The key distinction between this and Dispel Magic is that this is stopping a spell while it's being cast, rather than removing its effects after it already has been. And keep in mind that simply having the opposite effect of a given spell (e.g. positive vs. negative Status Buff; inflict/heal poison) is not enough to qualify as a counterspell. Compare Curse Escape Clause.
- Loads and loads of examples in Magic: The Gathering, including the Trope Namer. Each card in a player's deck (besides land cards) is considered a spell, cards such as Counterspell may be cast in response to "counter" the spell, sending it to the graveyard without having any effect.
- The iconic Counterspell, the card upon which so many others are based. The thing proved to be too overpowered; thus, it is no longer printed. We have a selection of weaker, fairer replacements like Cancel and Counterbore. However, development teams have occasionally misjudged a card, giving us more powerful variants like Mana Drainnote and Pact of Negation.
- Because of the tendency for counterspells to be countered (and those spells to be countered, and those...) a favorite is Last Word. That can, amusingly, be countered by Time Stop. Which can itself be countered....
- "Permission" decks are built entirely around this concept, and are so called because any time an opponent casts a spell, the Permission deck player almost always has the option of countering it, so if they decide it's not worth it, they are granting their opponent "permission" to cast it.
- Trap Cards are played in face-down position, after which they can be activated on either player's turn by flipping them face-up (sometimes requiring a specific condition to do so). The most iconic are those which can be activated when an opponent plays a certain type of card, and have the effect of negating that card and/or destroying it - examples include "Trap Hole" (for Monster summoning), "Magic Jammer" (for Spells) and "Seven Tools of the Bandit" (for other Traps).
- Counter Trap Cards are a subtype of Trap Cards which may only be used to counterspell, but have the highest Spell Speed in the game, meaning that a Counter Trap may only be counterspelled by another Counter Trap.
- Quick-Play Spell Cards are a subtype of Spell Cards which have the same Spell Speed as normal Trap Cards. They can be activated at any point in the user's turn, or played face-down and activated like Trap Cards. Some of their effects are similar to Trap Cards, while others allow the user to skip parts of their turn or take them out of order (which can prevent enemy Traps from triggering).
- Some Monster Cards, like "Horus the Black Flame Dragon LV8", can do this as long as they remain on the field.
- The "Nope" card in Exploding Kittens, which can cancel the effects of any other card except the titular Exploding Kitten or a Defuse card.
- Hearthstone has two mage secrets which function as this; "Counterspell" cancels the effect of the next spell cast by your opponent, and "Spellbinder" summons a 1/3 minion when your opponent casts a targeted spell, causing the spell to target the minion instead.
- My Little Pony: Equestria Girls Rainbow Rocks: Twilight Sparkle's strategy to counter the Dazzlings is to write a counterspell song against their siren voices; this is what motivate the Rainbooms to participate in the Battle of the Bands. However, this proves a daunting task even for a magic prodigy like Twilight (for a variety of reasons, including the need to be a song, that she's not in her usual form, in a magic-deprived world and without access to her spellbooks). In the end, they use a song written by Fluttershy and resort to raw Magic of Friendship to counter the Sirens.
- The Fellowship of the Ring. While the Fellowship is in Moria being pursued by orcs (and worse), Gandalf stays behind to hold a door closed. The opposition breaks through anyway. A few moments later Gandalf tells the rest of the Fellowship what happened.
"I could think of nothing to do but to try and put a shutting-spell on the door... Then something came into the chamber.. and then it perceived me and my spell.
What it was I cannot guess, but I have never felt such a challenge. The counter-spell was terrible. It nearly broke me. For an instant the door left my control and began to open! I had to speak a word of Command. That proved too great a strain. The door burst in pieces."
- An explicit spell and counterspell appear in Kelson's coronation duel against Charissa in Deryni Rising. Charissa begins:
- The shape of a dragon begins to coalesce from mist, and Kelson interrupts with the counter.
- Harry Potter has these on at least a theoretical basis, most directly seen in Harry Potter and the Philosopher's Stone when a teacher tries to curse Harry off his broom while another tries to counter it. The countercurse was not entirely effective, even though the latter teacher was more skilled than the former, suggesting that counterspells are imperfect as a defense. More common practice is to use shield charms, which block or deflect weak spells, or just use similar spell of equal power so that the two cancel out.
- This is one of the defensive tricks a practitioner can do in The Dresden Files.
- In Death Masks, when one of the Knights of the Blackened Denarius casts a spell conjuring up a bunch of snakes to attack his love interest, Harry Dresden performs a quick counterspell to get rid of them.
- In one of the short stories, a Grendelkin displays and boasts of his knowledge of countering magic, making it so Harry's hardest hits just flow off it like water.
- More than a few badguys — particularly powerful Sidhe, grendelkin, and the Fallen — are adept at countering magic, to the point that Dresden himself is rendered unable to use his magic against them. Fortunately, he's adept at adaptation and dirty fighting. For example, when faced with a cavalry charge of Sidhe nobility, rather than bring his will into direct conflict with 20-odd counterspells, he just trips their horses.
- In Turn Coat, Listens-to-Wind does a rain dance as a counterspell — this time, instead of negating the blasts coming at him, he just causes them to miss their marks.
- The RPG goes into a little more detail on how it's done — first, the mage has to do a Lore check to assess the strength of the spell he wants to counter, then he casts the counterspell equal to that amount of power. It's noted this usually takes too long to do as a defensive move, but it can be houseruled in as one.
- In the Doctor Who Expanded Universe book Millennial Rites, the Doctor and his former companion Anne Travers find circumstancial evidence suggesting a rich industrialist is preparing to summon the Great Intelligence. Anne, frantic to stop another invasion, immediately researches the counterspell necessary to banish it. However, it all goes to hell when it turns out the industrialist isn't going to summon the Intelligence, but rather, a very different being, and Anne uses the counterspell anyway. The incompatible spells mesh in the worst manner imaginable and drag London into an unstable Merged Reality of three different universes.
- Dungeons & Dragons:
- 2nd Edition, The Complete Bard's Handbook. Dwarven Chanters and Halfling Whistlers cannot cast spells, but they nonetheless study magic and learn how to counter spells they know with their Magic Music (dwarves by chanting, halflings by whistling or humming).
- 3rd Edition has a Counterspell mechanic. A prepared spell may be cast to nullify another caster's attempt to use the same spell. For example, a fireball can counter another fireball (but not delayed blast fireball, which is a different spell). Some spells are specifically opposed to and counter other spells (haste and slow may counter each other as well as themselves). Finally, dispel magic can be used as a universal counterspell but requires a unique "dispel check" to make the attempt.
- Taken up to 11 in 3.5 where the mechanic is given a short feat chain and a Prestige Class focused entirely on standing around and just countering every spell as it's cast.
- In 5th edition, this is done with a specific spell named Counterspell. It is now cast as a reaction, freeing the caster to do something else as an action instead of using the action to ready the spell.
- Spheres of Power has the Counterspell feat; allowing you to both counter and Dispel Magic.
- Warhammer's dispel dice are an example of this, being used solely to counter enemy spells. There are also various abilities and pieces of wargear that allow instant dispels (the ubiquitous Dispel Scroll), or increase the power of your dispel attempts, either through modifying the result or granting extra dispel dice.
- In Ironclaw Holy and Unholy spells counter each other, "Create Element" spells can counter spells of the opposite Element while "Move Element" spells counter the same Element, and the Misfortune, Repudiation, and Silence spells counter magic in general.
- One of the low-grade magician types in Shadowrun is the nega-mage, who can counterspell other magicians' sorcery but otherwise lacks paranatural power.
- Exalted: The sorcerous Emerald/Sapphire/Adamant Countermagic series, listed in order of increasing strength. They even have necromantic counterparts, called (again, in order of increasing strength) Iron/Onyx/Obsidian Countermagic. Spells targeted by these counters have a tendency to... explode.
- Mage: The Awakening, with its rather complex system of magic, has a fairly simple mechanism for counterspells. To counter obvious spells, a mage merely needs basic knowledge of one of the Arcanum used in its casting (e.g., a spell using Forces 3, Space 2 can be countered with Forces 1 or Space 1). If the mage knows none of those Arcana, he can still disrupt it with sufficient knowledge of the Prime Arcanum, which focuses on the basic pattern of magic; this Arcana can also allow him to disrupt more subtle magic.
- Invisible Sun: In a world of magic users, only one group has access to counterspells; Apostates, outliers who have been exiled from or voluntary left any of the magic Orders of the Invisible Church, are granted counterspell as an ability so they can stand against the often more powerful and better organized Order members.
- In Guild Wars, the Mesmer profession has a number of "interrupt" spells that only work on spells and chants, which are given this kind of flavour (as opposed to the interrupt skills available to physical attacker professions, which can usually interrupt actions of all sorts and are given a flavour of hitting you so hard you stop what you're doing).
- The Final Boss of Ōkamiden has its own version of the Celestial Brush and often nullifies your brushstrokes by crossing them out with his own. (Fortunately, this rule works both ways.)
- Can be done in Heroes of Might and Magic V if a hero learns the counterspell ability. When used, the hero forgoes their current action, and if an enemy uses a spell between now and their next action, the counterspelling hero spends twice the spell's cost in mana to stop the spell taking effect.
- World of Warcraft: Every class has an ability that does this in one form or another (colloquially known as "interrupts"), usually also preventing other spells from the same school from being cast for a few seconds. They only work on spells with a cast or channel time however, and some spells (mostly those used by monsters) are immune to them.
- Dragon Quest: Stopspell/Fizzle, in the series from the beginning, keeps your opponent from casting spells. It can be a lifesaver when facing spellcasting monsters, particularly those who can put you to sleep, heal themselves, put serious hurt on you or try to block your spells.
- In Final Fantasy VI, Celes' "Runic" command puts her in a defensive stance. If an enemy casts a spell while she's in this stance, she is triggered to absorb the spell through her sword, rendering it harmless and granting her the spell's casting cost in MP. However, this also works against you since Runic can also absorb spells that your party casts.
- In Tales of Berseria, Magilou's unique Soul Absorber ability allows her to instantly interrupt the casting of a nearby enemy, then immediately unleash a powerful spell of her own as a counterattack.
- The Order of the Stick:
- Vaarsuvius is making good use of D&D's counterspell rules when battling Samantha the bandit sorceress. V notes that counter-spelling is a perfectly legitimate, if rarely used, means of disabling a spellcaster.
- When Tsukiko is restrained by her own wights, she tries using a "Shout" spell (one of the few options left to her, as it can be cast by voice alone) against Redcloak, who just counterspells it (with Dispel Magic, according to The Giant, since Shout isn't a cleric spell).
- The technique Roy learned from his late grandfather is designed to interrupt spellcasting, thus giving him an edge versus spellcasters in a world where Linear Warriors, Quadratic Wizards is in effect. It is later revealed that it's a Secret Art known as Spellsplinter Maneuver. A character remarks that no Fighter alive knows the technique anymore.
- Later on, Vaarsuvius is shown to have upped their skills by picking the "Improved Counterspell" feat, which allows V to counter even clerical spells that aren't on a wizard's spell list.
- In The Far Side Of Utopia there is mana interference, which seems to be pretty much exactly this — when it's used the Instant Runes get broken and the spell being cast fails.
- Unsounded: Spells provide detailed instructions for seizing and manipulating Aspects of reality — like, say, pulling Heat out of the air into a fireball — so a very skilled spellwright can snatch those Aspects out of an active spell and take control. Duane is very skilled.