History Main / TakesOneToKillOne

[[folder:Real Life]]
* British forces in the Battle of the Atlantic, fighting against the German U-boat menace, were commanded by a submariner.
* Until cannons improved, the best (but not only) way to sink an ironclad ship was to have another ironclad, or better yet multiple ironclads, duel it until either the funnel or steering system was damaged. After this, the wooden ships could join in and they’d all pound on the enemy’s armor with their guns until something gave way.
* Diamonds can only be scratched by other diamonds.... Or [[ScienceMarchesOn even harder substances]]. The first of which, cubic boron nitride, was synthesized in 1957.
* Averted with scorpion venom. Scorpions are immune to the venom of their own species.
** On that note, antivenom in general. Created from the very venom it's used to treat.
* Even today with modern rocketry, guidance, computers, and radar successfully intercepting an incoming ballistic missile with one of your own is an incredibly difficult and still not completely reliable task. For the early to mid-Cold War anti-ballistic missile designers tasked with protecting their cities from the enemy it was practically impossible to get their anti-missile missiles to hit incoming [=ICBMs=] with enough accuracy to stop them. So what did they do? Give up on the concept of a direct hit and arm their missiles with proximity fuses and [[NuclearOption nuclear warheads]] of their own so a near-miss would still hopefully vapourize, melt, disable the electronics of, or trigger the premature (and incomplete) detonation of the enemy warhead. For interceptions in atmosphere the yield was usually a few to a few dozen kilotons. [[ExplosionsInSpace For interceptions in space]] where you couldn't rely on atmospheric blast effects and where collateral damage was less of a concern the payloads were either neutron bombs or warheads optimized to radiate in x-rays with yields between a few hundred kilotons to a few megatons hoping to fry enemy warheads with radiation. In the Soviet Union such systems were only deployed around Moscow and in America it was only deployed briefly around missile silos in the middle of nowhere as, [[NotInMyBackyard oddly enough, some people were nervous about the presence of facilities that were supposed to result in nuclear detonations over the cities they lived in.]]
* In addition to the above during the brief period in the early Cold War before [=ICBMs=] became commonplace and everybody expected a nuclear war to be fought with bombers the US air force decided they needed a way to reliably kill large fleets of fast Soviet nuclear bombers while guided missile technology was in its infancy. Their solution? Take normal interceptors and arm them with unguided rockets which make up for the fact that they will inevitably miss by virtue of the fact the [[https://en.wikipedia.org/wiki/AIR-2_Genie rocket]] was tipped with a [[NuclearOption tactical nuclear bomb]] on a 12-second fuse with a lethal radius of 300 meters.
[[/folder]]

There are ways on how this is accomplished:

SubTrope of MutualDisadvantage. SuperTrope to MagicMustDefeatMagic. An opposite of TacticalRockPaperScissors where each type of combatant has some other capable of [[CurbStompBattle curb stomping]] it. However, this can be a subtrope of ElementalRockPaperScissors if an element happens to be weak against itself. Compare BeatThemAtTheirOwnGame, HoistByHisOwnPetard, and SummonBiggerFish. Contrast LikeCannotCutLike and CounterpartArtifacts. See also SerialKillerKiller, which usually doesn't involve the supernatural.

* In ''Anime/TheBigO'', one of the few things that can damage a [[GiantMecha Megadeus]] is another [[GiantMecha Megadeus]], though this is less an issue of compatibility than a matter of sheer firepower. There have been several organic threats which could have legitimately beaten a Megadeus.

** The director of ''Anime/MobileSuitGundamSEED'' outright said that "Only a Gundam can beat a Gundam" was part of the series' design philosophy. In this case it was aided by the fact that most Gundams use Phase Shift Armor, which is immune to physical damage, meaning that only beam weapons can hurt them. Gundams themselves are also the first suits to ''have'' beam weapons, which are otherwise mounted on ships, [[PointDefenseless making them too slow to be effective against agile mobile suits]]. It's not until late in the series that miniaturized beam weapons are suitable for mass production, and even then the Gundams have defenses against them (albeit less comprehensive than their defense against projectile weapons) that ordinary mobile suits lack.

** Gundams in ''Anime/MobileSuitGundamTheWitchFromMercury'' are suits with a "Permet" BrainComputerInterface that grants incredible reaction times and a overwhelming swarm of {{Attack Drone}}s. Their GUND format would have become the standard decades earlier if [[DeadlyUpgrade the damage they do to their pilots]] hadn't gotten them outlawed. After Elan piloting the Gundam Pharact soundly defeats Guel, an AcePilot in a non-Gundam AceCustom, he states that only a Gundam can defeat another Gundam. We're only shown to the contrary when a Gundam is heavily outnumbered and/or faces an anti-Permet PowerNullifier--and Gundams can [[ScissorsCutsRock outright ignore the latter]] by increasing the intensity of its system, although this puts a potentially fatal strain on the pilot. Even among Gundams, however, Gundam Aerial specifically [[OneHeroHoldTheWeaksauce has overcome the limitations and drawbacks of the GUND format]], putting it in a class of its own -- at its maximum potential, not even another Gundam can defeat it.

* In ''Franchise/{{Naruto}}'': the jinchuriki of the Ten-Tails are immune to all ninjutsu, since the Ten-Tails is the progenitor of all chakra, and its power is virtually the same as the Natural Energy of the world itself. However this also means that Sages, who amplify their techniques with Natural Energy to use senjutsu, are able to harm them.
* ''Anime/NeonGenesisEvangelion'': The Evas [[spoiler:who are pretty much Angels anyway]] are usually the only things on Earth which can fight an Angel and win, because only they can break the Angel's AT fields. To be more accurate, Angels project AT fields so strong that only the similarly-sized Evangelions possess the power necessary to breach them. There are cases where the Evas weren't directly responsible for the victory. One was beaten by [[FeedItABomb blowing up a destroyer in its mouth]], Ramiel was taken down by a positron cannon fed with the entire country's power supply (wielded by an Eva, but the cannon did the work). Certain other options exist to hit the 180 million megawatt figure stated to be necessary to overcome Ramiel's AT-Field, which was one of the strongest of all the Angels (behind Tabris and Zeruel, most likely). The largest nuclear devices, for instance, could likely knock out an Angel, though nuking them isn't exactly an ideal solution.

** [[spoiler:It is possible to stop Walpurgisnacht, but it takes an large group of magical girls and they are all but guaranteed to sustain catastrophic casualties. Considering that Homura unleashes an army's worth of ammunition on Walpurgis to no avail while regular magical girls tend to use much less impressive amounts of firepower, it is possible that Walpurgisnacht '''is''' weaker to magical weapons, but just enough to turn the battle from "[[HopelessBossFight impossible]]" to "[[PyrrhicVictory just barely doable]]".]]

* In ''Fanfic/TheBridge'', it takes one [[PhysicalGod Nexus of Magic]] to have any chance of killing or defeating another one on one. This is because they're simply so much stronger than anything else on ''either'' world that the runner up, Grand King Ghidorah, would be utterly annihilated in a fight with any of them even at only 30-40 percent of their full power. They ''can'' technically be defeated, but it would take an entire ''army'' of extremely powerful kaiju to have anything resembling a chance of doing so and likely suffer heavy losses in the process. The Guardian Beasts, who if they hadn't been awakened prematurely would be stronger than ''Godzilla'' in strength, were created for primarily for the purpose of beating ''one'' of them when he inevitably escaped his prison and it took the ''entire'' Mothra and Battra species to lock him in it in the first time at the cost of their population being reduced to one each. [[spoiler:The ''only'' being who has ever defeated Grogar, the Nexus of Dark Magic, was Harmony, the Nexus of Light Magic, and even then it was more by cunning and planning than any difference in their power.]]

** ''Film/{{Wonder Woman|2017}}'': Diana was led to believe that the God-Killer, a legendary weapon forged by Zeus himself to slay other gods (specifically Ares) is a sword, which she steals while fleeing Themyscira to join the war. When she finally confronts Ares in battle, he easily destroys the sword, and reveals to her the truth: the only thing in the world that can kill a god is another god. The actual God-Killer is Diana herself, as the daughter of Zeus. And she ends up doing just that.

* ''Film/TransformersRevengeOfTheFallen:'' The Fallen is, as his name implies, a [[FallenHero Fallen Prime]]. It is said that only another Prime can kill him, and naturally Optimus is the only one left. Showing a high level of GenreSavvy, he refuses to engage Optimus, and simply stays in his base until Optimus has been killed. Once Optimus gets better (as Optimuses do), the Fallen ''still'' avoids getting close to him. [[spoiler:He doesn't engage Optimus until his plan has been foiled, by which point he has nothing left]].

** Warhammer tropes really should indicate when they were the case since the game zig-zags many tropes with each edition. Before 8th edition, tanks and similar vehicles were invulnerable to most infantry weapons and generally had to be engaged with anti-vehicle weapons. The rules in most editions also forbade most units from splitting their fire; either the anti-tank squaddie wasted his big gun on the same infantry his unit shot at, or the riflemen wasted their shots on the tank so the anti-tank trooper could target it. As of eighth edition, every attack has some minimal chance to inflict ScratchDamage against any target and splitting fire has become easier.

* {{Downplayed|Trope}} in that a ''Videogame/CustomRobo'' commander can technically be defeated by relentless carpet bombing, but as robos become cheaper and more widely available robo commanders become the only economical means of combating other robo commanders, especially in densely populated areas. Then came, Rahu, which can ''only'' be beaten by robo commanders and is only beatable at all because, [[OnlyTheAuthorCanSaveThemNow for reasons no one can explain]], the world destroying menace decided to start using a robo. A [[NerfArm toy robo]] rather than, say, a military grade one.

** The "Faith" stat dictates not only a mage's attack power, but how much damage they incur from enemy spells as well. A character with very low Faith is thus virtually immune to magic, while a character with high Faith is very vulnerable.

* In ''VideoGame/FireEmblemAwakening'' the last act of the game is spent finding a way to stop Grima, the ''BigBad'' of the game. Your party goes to a shrine to [[BigGood Naga]] in order to perform an awakening ceremony to hopefully give the [[SwordOfPlotAdvancement Falchion]] the power to slay Grima. However, Naga reveals after the ceremony that slaying Grima with the Exalted Falchion will only put him into a 1000 year sleep, and only his own power is strong enough to truly slay him. [[spoiler:This causes the Avatar to realize that since they were supposed to be the Fell Dragon's vessel, they can also tap into his power, and thus permanently kill him, at the cost of their life.]]

** Types that usually resist themselves [[note]]Fire, Water, Grass, Electric, Ice, Poison, Psychic, Dark and Steel[[/note]] get a taste of this in the Inverse Battles introduced in Generation 6. Ice especially as it has no other resistances in normal gameplay, so a pure Ice type in an Inverse Battle would only take super effective damage from Ice attacks.

* ''[[VideoGame/Sonic3andKnuckles Sonic 3 & Knuckles]]'': The first form of the last boss must be damaged with its own missiles. Despite the fact that you are invincible, ramming the boss not only does no damage, but [[StalkedByTheBell wastes the precious little seconds you have]].

* PlayedWith in ''VisualNovel/DiesIrae''. While killing an Ewigkeit user is doable in theory for a normal human, in actual practice it is nigh impossible. This is due to the way Die Ewigkeit works as it gives it's users effectively extra lives on top of a whole host of other abilities. Thus the only really effective way to kill one is to use weapons that take "several lives on each use", and normal such weapons like bombs and nukes just aren't practical. Hence why Ahnenerbe exists, weapons wielded by Ewigkeit users, as they attack the soul directly and can take all those extra lives with more limited attacks. The only known instance of a normal human killing an Ewigkeit user was [[spoiler:Shirou killing Wilhelm at the end of Kasumi's route]], and that relied on a very specific loophole created by the users own powers.
* PlayedWith in ''VisualNovel/FateStayNight'' and related works. [[MadeOfMagic Servants]] are said to only be vulnerable to other Servants, but while they are immune to conventional methods of attack (including military hardware up to and including nuclear bombs), in reality any ability infused with magical energy should be able to harm them. In practice, however, Servants are so superhuman that there are extremely few modern magi capable of actually landing a hit on them, meaning that the only way to reliably harm a Servant is through another Servant. Rin claims that even a paper knife can harm one, but only as long as it's wielded by a Servant and infused with mana. That being said, it's entirely possible for a magus to harm a Servant under the right conditions; Rin was able to claim one of Berserker's twelve lives by catching him off-guard with her magical jewels, [[spoiler:and Shirou's copies of legendary weapons allow him to fight Servants for a limited time and even defeat them]].

* ''WesternAnimation/FinalSpace'': Implied in "The First Times They Met" with the evil [=KVN=]s. They are stated to be nearly indestructuble, which is demonstrated throughout the episode, but towards the end the main KVN easily kills the last one himself by [[AndShowItToYou punching right through him and tearing out a vital heart-like component]].

* Until cannons improved, the best (but not only) way to sink an ironclad ship was to have another ironclad, or better yet multiple ironclads, duel it until either the funnel or steering system was damaged. After this the wooden ships could join in and they’d all pound on the enemy’s armor with their guns until something gave way.

* Even today with modern rocketry, guidance, computers, and radar successfully intercepting an incoming ballistic missile with one of your own is an incredibly difficult and still not completely reliable task. For the early to mid-Cold War anti-ballistic missile designers tasked with protecting their cities from the enemy it was practically impossible to get their anti-missile missiles to hit incoming [=ICBMs=] with enough accuracy to stop them. So what did they do? Give up on the concept of a direct hit and arm their missiles with proximity fuses and [[NuclearOption nuclear warheads]] of their own so a near-miss would still hopefully vapourize, melt, disable the electronics of, or trigger the premature (and incomplete) detonation of the enemy warhead. For interceptions in atmosphere the yield was usually a few to a few dozen kilotons. [[ExplosionsInSpace For interceptions in space]] where you couldn't rely on atmospheric blast effects and where collateral damage was less of a concern the payloads were either neutron bombs or warheads optimized to radiate in x-rays with yields between a few hundred kilotons to a few megatons hoping to fry enemy warheads with radiation. In the Soviet Union such systems were only deployed around Moscow and in America it was only deployed briefly around missile silos in the middle of nowhere as [[NotInMyBackyard oddly enough some people were nervous about the presence of facilities which were supposed to result in nuclear detonations over the cities they lived in.]]
* In addition to the above during the brief period in the early Cold War before [=ICBMs=] became commonplace and everybody expected a nuclear war to be fough with bombers the US air force decided they needed a way to reliably kill large fleets of fast Soviet nuclear bombers while guided missile technology was in its infancy. Their solution? Take normal interceptors and arm them with unguided rockets which make up for the fact that they will inevitably miss by virtue of the fact the [[https://en.wikipedia.org/wiki/AIR-2_Genie rocket]] was tipped with a [[NuclearOption tactical nuclear bomb]] on a 12 second fuse with a lethal radius of 300 meters.

* Frequently [[InvertedTrope inverted]] by the actual real life military.
** Often, the best way to kill or disable a hostile unit is using something completely different against it; for example, battleships fell out of favor after [=WW2=] because too many of them had been destroyed by aircraft, and a tank's worst enemy isn't necessarily always another tank. This is often because the best use of tanks is in destroying supply lines, rather than because tanks are not effective against other tanks.
*** The general rules is tanks beat artillery, artillery beats infantry, and infantry beats tanks. It does depend on having the proper load out, but tanks can normally speed through artillery fire zones and survive the initial shapenel hits to engage artillery before they can readjust their aim. Artillery can pin down infantry that can't quickly exit the danger zone and who are completely vulnerable to sharpnel. Meanwhile, unsupported tanks aren't good against infantry that have AP rockets/missiles (or even sometimes just molotovs or AP 50 cal rounds or equivalent) because there's too many angles where tanks are just simply blind at any given time. That being said, there are specific tank destroyers whose job really is to just kill other tanks. Meanwhile, artillery is usually the best counter to artillery because rushing in tanks can get them killed by tank destroyers or infantry. As for infantry, entire units can be held in place by a single sniper. [[StrategyVersusTactics Every situation is different.]]
** Averted with submarines, HotSubOnSubAction notwithstanding. [=WW2=] and earlier subs, largely blind underwater and equipped mainly with unguided torpedoes, were basically incapable of attacking each other at all unless the target happened to be on the surface (in which case it would have been just as vulnerable to gunfire and aircraft), and while more modern ones are equipped with weapons that can seek out and destroy another submarine those weapons can often be just as easily be mounted on other platforms (such as helicopters, against which a submerged sub under attack cannot even return fire).

*** The general rules is tanks beat artillery, artillery beats infantry, and infantry beats tanks. It does depend on having the proper load out, but tanks can normally speed through artillery fire zones and survive the initial shapenel hits to engage artillery before they can readjust their aim. Artillery can pin down infantry that can't quickly exit the danger zone and who are completely vulnerable to sharpnel. Meanwhile, unsupported tanks aren't good against infantry that have AP rockets/missiles (or even sometimes just molotovs or AP 50 cal rounds or equivalent) because there's too many angles where tanks are just simply blind at any given time. That being said, there are specific tank destroyers whose job really is to just kill other tanks. Meanwhile, artillery is usually the best counter to artillery because rushing in tanks can get them killed by tank destroyers or infantry. As for infantry, entire units can be held in place by a single sniper. [[StrategyVsTactics Every situation is different.]]

* The Mechon of ''VideoGame/XenobladeChronicles1'' are all but immune to conventional weapons. However, weapons crafted from trashed Mechon parts can cut through their armor just fine.

*** Hoopa Confined and Lunala are both dual-type Psychic/Ghost, so they have the dubious honor of having the only type combination with a [[QuadDamage double weakness]] to one of ''their own types''! [[labelnote:*]]Had a Pokémon with this type combination existed in the first generation, it would've truly had no weaknesses--it was immune to Ghost, Bug-type moves did neutral damage, and Dark didn't exist. Not like those first two mattered, what with said moves being horribly underpowered.[[/labelnote]]

%% Image replaced per Image Pickin' thread: https://tvtropes.org/pmwiki/posts.php?discussion=1446802795008996100
%% Please do not change or remove without starting a new thread.

[[quoteright:350:[[ComicBook/ThirtyDaysOfNight https://static.tvtropes.org/pmwiki/pub/images/eben_vicente.png]]]]
[-[[caption-width-right:350:Ah, the classic vampire weaknesses: [[WeakenedByTheLight sunlight]], [[VampiresHateGarlic garlic]], {{silver|HasMysticPowers}}, and another vamp's fist through your skull.]]-]

%% Caption selected per Caption Repair thread: https://tvtropes.org/pmwiki/posts.php?discussion=1404492079030138900
%% Please do not replace or remove without discussion there.

* ''Anime/NeonGenesisEvangelion'': The Evas [[spoiler:who are pretty much Angels anyway]] are usually the only things on Earth which can fight an Angel and win, because only they can break the Angel's AT fields. To be more accurate, Angels project AT fields so strong that only the similarly-sized Evangelions possess the power necessary to breach them. There are cases where the Evas weren't directly responsible for the victory. One was beaten by [[FeedItABomb blowing up a destroyer in its mouth]], Ramiel was taken down by a positron cannon fed with the entire country's power supply (wielded by an Eva, but the cannon did the work). Certain other options exist to hit the 180 million megawatt figure stated to be necessary to overcome Ramiel's AT-Field, which was one of the strongest of all the Angels (behind Tabris and Zeruel, most likely). The largest nuclear devices, for instance, could likely knock out an Angel, though nuking them isn't exactly an ideal solution.

* In ''Anime/YuGiOhZEXAL'' (both, anime and manga), the [[GottaCatchEmAll Numbers]] monsters cannot be destroyed in battle except against another Number. {{Subverted}} in that they can still be destroyed by card effects, and it's entirely possible to [[PowerNullifier negate their invulnerability]] so that they can be destroyed by ''any'' monster.
* In ''Literature/{{Baccano}}!'', the only way an immortal can die is to be [[IdentityAbsorption absorbed]] by another immortal.
* ''Anime/PuellaMagiMadokaMagica'' seems to {{play|ingWithTropes}} with this trope. At first, the Magical Girl magic appears to be the only way to kill Witches (straight trope), but it is eventually revealed that [[spoiler: Akemi Homura actually uses firearms and bombs]] (subversion) [[spoiler: to kill Witches off, because of her comparatively weak offensive powers]]. And then, in episode 11, [[spoiler: she blasts Walpurgis Night with literally thousands of explosions and doesn't even manage to scratch her (keep in mind she usually manages to kill witches off with barely one hundredth this firepower). For all intents and purposes, it turns out Walpurgis Night can't be stopped by either firepower ''or'' magic, and the only reason she is defeated is the RealityWarper power of Madoka's wish which causes a CosmicRetcon to erase all witches from existence altogether]] (thus, double subversion).
** [[spoiler:It is possible to stop Walpurgisnacht, but it takes an large group of magical girls and they are all but guaranteed to sustain catastrophic casualties. Considering that Homura unleashes an army's worth of ammunition on Walpurgis to no avail while regular magical girls tend to use much less impressive amounts of firepower, it is possible that Walpurgisnacht '''is''' weaker to magical weapons, but just enough to turn the battle from "[[HopelessBossFight impossible]]" to "[[PyrrhicVictory just barely doable]]".]]
* ''Anime/HeroicAge'': All Nodos are so exceedingly powerful that the only thing that can fight a Nodos is another Nodos. Anything else is certain to get curb stomped. Even then, battles between Nodos can go on for quite a while. At one point, a Nodos battle lasts for ''300 hours straight''.
* Invoked in ''Manga/YuYuHakusho'' by Kurama when he and Hiei fight against a robot made of an "indestructible" metal. Kurama leads its stretchable claws to crash into each other, which breaks the metal apart and allows him to destroy its exposed internal components.
* In ''Manga/{{Claymore}}'', the eponymous warriors are humanity's only hope against the yoma — because they are infused with yoma blood to gain control over yoki, their demonic energy. On the flip side, all Claymores run the risk of turning into ''super'' yoma, a.k.a. Awakened Beings. [[spoiler:However, the beings the Claymores were really meant to fight are the Dragon-people whose flesh is the source of yoma.]]
* ''Manga/AttackOnTitan'' is a complicated example. First there is special gear used to fight titans. It is definitely possible to kill titans in this manner but there is a often a large death toll. Then it's revealed that the only thing that can reliably hurt a Titan is another Titan. [[spoiler:Which makes the Titan Shifters extremely valuable allies]]. The gear used by normal humans is much more limited in application and effectiveness in comparison. For example, [[spoiler: Eren doesn't kill a single titan while in his human form for the entirety of the first season, but in Titan form he's brutally effective and even out-fights the dreaded Armored Titan in hand-to-hand combat.]]

* In ''Manga/JoJosBizarreAdventure'', a Stand zig-zags this with the ways it can be harmed. A Stand is [[PowersDoTheFighting a telekinetic construct of its user's spirit]], usually InvisibleToNormals, and can only be harmed by another Stand (which also inflicts [[{{Synchronization}} similar damage]] on its Stand User). However, a Stand User is just as vulnerable as normal people to being killed by conventional means, such as guns or swords; killing the Stand User will also destroy the Stand. [[spoiler:Then there's how the [[OurGhostsAreDifferent spirits of Ghost Girl's Alley in Morioh]] are able to flat-out grab and destroy Stands by ripping them apart (as shown by how they destroy the Stand Killer Queen and Kira's spirit suffers a similar fate thanks to synchronization), though this might still technically count since Stands ''are'' spiritual-based and technically 'ghosts' themselves.]]

* A variant is used in ''Manga/TokyoGhoul''. [[HunterOfMonsters Ghoul Investigators]] hunt Ghouls using a weapon called a Quinque, which is made using a Ghoul's [[ShapeshifterWeapon kagune]]. The audience learns this when Kureo Mado brings out his Quinque to kill [[SacrificialLamb Mrs. Fueguchi]], who recognizes it as having been [[KickTheDog made from her husband]]. Later on, he brings out his newest Quinque to attempt to kill her daughter — he had it made from Mrs. Fueguchi after killing her. However, this is the ''most effective'' way of fighting ghouls available to humans. They could, theoretically, beat them to death with their bare hands, but ghouls have a physical edge in that area.
* ''Franchise/DragonBall'':
** King Piccolo was utterly invincible to any human who didn't know the Evil Containment Wave, which kills the person who uses it. Only Goku manages to outmatch Piccolo and later his son Piccolo Jr. They are both aliens sent to Earth to save their lives.
** When they were introduced, the Saiyans were so overwhelmingly powerful compared to any enemy that the Earth had ever faced that even after a year of training, the Earth's fighters can't even take down Nappa, who is far weaker than Vegeta. Only Goku and Gohan were able to turn the tides and repel the Saiyans, and Goku is a Saiyan and Gohan is a Saiyan hybrid.
* Played with in ''Manga/{{Hellsing}}'' where almost everyone constantly thinks that in order to kill a monster you either need a monster or to somehow become a monster. By contrast, Alucard, the biggest scariest monster around, thinks the only thing that can truly kill him is a human. This is because he got his ass kicked by Dr. Abraham Van Helsing in his backstory.

* ''Manga/{{Bleach}}'': Baraggan is [[MadeOfIron resilient enough]] to withstand a FantasticNuke with only minor injury and can unleash an unstoppable, infectious [[MakeThemRot wave of decay]] at will. He's killed by teleporting an infected hand into his body, where his own power rots him into nothingness.

* ''Anime/DigimonAdventure:'' [=MetalEtemon=] effectively has NighInvulnerability when he is met as not only is he a Mega-level Digimon, but his entire body is coated in Chrome Digizoid, the hardest substance in the entire world. Zudomon was able to leave a crack on his body when he threw his Vulcan's Hammer at him as the hammer is also made out of Chrome Digizoid, allowing him to be killed by [=SaberLeomon=].

* ''ComicBook/TheBoys'': The Homelander is basically Superman with none of Superman's positive traits. In order to make sure they could control him, Vought apparently raised him next to a nuke, and [[spoiler:cloned him, raising the clone for the sole purpose of taking out the Homelander so as to have a loyal equivalent in case of betrayal. Unfortunately, the clone (Black Noir), being unable to carry out the mission it was created for, took matters into its own hands by filming itself committing atrocities so the Homelander would think he'd committed them]]. When the Homelander finally snaps, rebelling and killing Vought's puppet president, [[spoiler:Black Noir]] finally gets to intervene.

* In the ''Fanfic/JWITCHSeries'', it turns out that in addition to his canonical weakness to onions, Tarakudo can only be injured by [[CastingAShadow shadow powers]] like his own. [[spoiler: This gives Jade an advantage over him when she becomes the [[SixthRanger Guardian]] of [[DarkIsNotEvil Shadows]].]]
* In ''[[https://www.fanfiction.net/s/2070203/1/A-New-World A New World]]'', the surviving heroes need to track down [[TheMole Andrew]]. When they learn that he's in San Diego, Xander quickly concludes that he's going to Comic-Con; and while that can attract a crowd of up to 50,000, he's pretty sure he knows which stands Andrew will head to. As Faith puts it:
-->"It took a nerd to catch a nerd."

* Franchise/DCExtendedUniverse:

* Franchise/MarvelCinematicUniverse

* Franchise/MonsterVerse: The Menace vs. Menace kind, mainly ''Heroic Menace vs. Evil Menace''. Although the government and military would much rather attempt killing [[Characters/MonsterVerseKaiju the Titans]] on their terms using manmade weaponry, the reality is that MilitariesAreUseless against these gigantic, ancient, borderline-EldritchAbomination animals; and whether humans admit it or not, humanity is ultimately reliant for survival on the continued existence of Protector Titans such as Godzilla and Kong, who keep the non-Alpha Titans in check via AsskickingLeadsToLeadership and who will duel and defeat the more threatening Titans such as Ghidorah and others, with the government's and Apex Cybernetics' attempts to find a way of reaching Godzilla and Kong's power levels always backfiring horribly.
* ''Film/Ninja3TheDomination''

** Nicodemus Archleone, leader of the Denarians, is protected by the noose that hung Judas, which regenerates damage from any cause... [[spoiler: except for itself.]]

* ''Literature/JourneyToChaos'': Eric's plan at the start of ''Literature/TranscendingLimitations'' is to become a god (partly) to be better able to defend himself from [[spoiler: Gruffle]], who is now a GrimReaper.
* Comes up with regard to the unmage in ''[[Literature/TheCircleOpens Magic Steps]]''. Because the nature of unmagic is to negate true magic, all the power of the entire mage body of Winding Circle (one of the two great schools of magic in that part of the world) is useless against the unmage. The only thing that can counter unmagic is unmagic, which requires either another unmage (which Winding Circle doesn't have) or Sandry's [[UniqueProtagonistAsset unique power to "spin magic"]].
* ''Literature/TheRavenTower'': Gods can only be killed by an attack from another god or by losing all of their power. Of the known [[KillTheGod deicides by humans]], one used a weapon that had been imbued by the victim god to strike its targets dead, and the other starves the god to death by cutting off the HumanSacrifice it needs to fulfill a MagicallyBindingContract it had entered.

* ''{{Series/Delete}}'': Lucifer made a second AI tasked to destroy the first based on this theory. The first easily destroys it.

* One episode of ''Series/XenaWarriorPrincess'' dealt with a villain making weapons out of Hephaestus's metal, which can only be damaged by other weapons made of Hephaestus's metal. [[spoiler: Including, it turns out, Xena's chakram.]]
* In ''Series/KamenRiderZiO'', the villainous [[EvilKnockoff Another Riders]] have ResurrectiveImmortality and can only be beaten permanently by the powers of the Rider they imitate. Unfortunately, their existence has the side effect of [[RetGone retconning the heroic Riders out of existence]]; fortunately, Zi-O's whole gimmick is PowerCopying. Fellow power-copier Series/KamenRiderDecade could presumably also do the job, but [[spoiler:he spends most of the series pretending to be evil as part of a StealthMentor act.]] In TheMovie, Series/KamenRiderDenO (who's immune to changes in the timeline) demonstrates that the originals can do it too if they can dodge the retcon; later on in the series, [[spoiler:mounting time paradoxes eliminate the retcon element, meaning that more Legend Riders actually get to help him battle their evil doppelgangers]]. Zi-O also eventually gets around the restriction by using a MidSeasonUpgrade, as it serves as an ImmortalBreaker.
* In ''Series/EmeraldCity'', Dorothy has been told that only a witch can kill a witch. So when she runs into the Witch of the East, who immobilizes her with magic and takes her gun, demanding to know how it works, Dorothy tricks her into pointing the gun at her own head and pulling the trigger, thus [[BoomHeadshot killing herself]].
* In ''Series/{{Demons}}'' only vampires can kill other vampires. Anyone else first has to shoot them with a high-tech bullet containing their DNA reanimated by electricity, which turns them back into humans.

* In ''TabletopGame/WerewolfTheApocalypse'', one of the setting ending scenarios has the Wyrm having become so powerful that only its own weapons can even hurt it.

* In ''TabletopGame/{{Deadlands}}'', TheDragon to the [[BigBad Reckoners]], Stone can only be killed either by [[spoiler: shooting him with bullets that should've killed him on Gettysburg, some of which are in his guts]] or by any weapon shot by his own hands.

* In ''TabletopGame/{{BattleTech}}'', mechwarriors often boast that to take down a [[WalkingTank BattleMech]] requires another. Other armed forces (combat vehicles, infantry) could conceivably do so, either with rare super-powerful vehicles with [=BFGs=] of their own, or [[WeHaveReserves lots of casualties]], but the [=BattleMech=] remains king of the battlefield because of the sheer tenacity (due to compartmentalized construction) and low manpower requirements to deploy (just the pilot).
** This claim is just as often shown to be bullhonkey, especially by those factions who still embrace 'traditional' combined-arms warfare (Clan Hell Horses in particular). Battlemechs are in many ways treated as heavy cavalry was in the medieval ages: Undoubtedly powerful, but just as much because the way societal factors (a FeudalFuture full of low-population-density planets where UrbanWarfare is rare, available manpower is restricted, and strategic mobility is king) than due to technological ones.
** Because of its simplicity and brutality, the ''Awesome'' Assault Battlemech quickly gained a reputation for being a very difficult opponent, which led to an in-universe saying: "The only defense against an ''Awesome'', is another ''Awesome''." While this isn't strictly speaking ''true,'' its legendary toughness and firepower make it hard to counter directly without employing another ''Awesome'' against it.
* ''TabletopGame/{{Shadowrun}}'' uses this heavily. All scenarios take part on three planes -- the physical plane ('our' reality), the astral/magical plane (accessible to mages), and on the Matrix (accessible to deckers and technomancers). The three planes commonly interact, and when they do having monopoly on power in one of those planes gives you considerable power to influence the outcome of the scenario (though usually it's 'won' in the physical one), and thus all shadowrunning teams -- as well as whoever you're hired to run against -- should be expected to project power in all three planes. The most common example is SummonMagic, which hires spirits from the astral plane to manifest into the physical world, where they're powerful entities that are nigh-ImmuneToBullets. If your team has no mage or phys adept to banish or magically beat them into submission, your sammie isn't going to cut it against them. Similarly, if an opposing decker gets ahold of traffic control for your self-driving car via the Matrix, that car isn't going to help you chase down that escaping enemy any time soon.

* ''[[VideoGame/Sonic3andKnuckles Sonic 3 & Knuckles]]'': The first form of the last boss must be damaged with its own missiles. Despite the fact that you are invincible, ramming the boss not only does no damage, but [[StalkedByTheBell wastes the precious little seconds you have]].

* "???"-type enemies in ''VideoGame/AlterAILA Genesis'' are the enemies who use Psych-elemental attacks the most often, but they are also the only enemy weak to it.
** Many other enemies do this too; robots use Shock attacks the most, and humanoids tend to use Force, both of which are the elements they're most weak to.
* ''VideoGame/FinalFantasyTactics'':
** The "Faith" stat dictates not only a mage's attack power, but how much damage they incur from enemy spells as well. A character with very low Faith is thus virtually immune to magic, while a character with high Faith is very vulnerable.
** Low Faith isn't quite as good as it sounds, because it makes the character virtually immune to ''all'' magic, including ''healing spells''. So a character can be impervious to magic, but only at the price of having to rely entirely on items for healing. Though it's actually not a bad trade-off in this game.
* In ''VideoGame/PaperMarioTheThousandYearDoor'', during the InevitableTournament, one of your enemies is a pair of metallic, spike-covered critters... you can't hurt them with jumping-attacks, hammers, fireballs, or anything else. In fact, it's a HopelessBossFight... until Yoshi Jr. joins you for the rematch. By eating one and spitting it at the other, he's capable of damaging them - because, as it turns out, their only vulnerability is themselves.
* In ''Franchise/TheElderScrolls'' series, [[OurDragonsAreDifferent dragons]] are [[TheAgeless ageless]] beings with [[DragonsAreDivine divine]] souls, akin to [[DragonsAreDemonic highly destructive]] [[OurAngelsAreDifferent angels]]. While anyone of sufficient ability can slay the physical form of a dragon, [[DeaderThanDead permanently killing one]] requires [[YourSoulIsMine absorbing its soul]], something only beings who also have dragon souls can do. In order to serve as a [[HunterOfHisOwnKind natural predator]] to the [[ResurrectiveImmortality functionally immortal]] dragons, Akatosh, the draconic God of Time and [[TopGod chief deity]] of the [[SaintlyChurch Nine Divines Pantheon]], created the [[TheChosenOne Dragonborn]], rare mortals gifted with the immortal souls of dragons. Naturally, dragons see these "Dovahkiin" as [[HumanoidAbomination Humanoid Abominations]] for what they are capable of. The PlayerCharacter of ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'' is the so-called "Last Dragonborn", sent to oppose the return of [[BigBad Alduin]] the [[BeastOfTheApocalypse World Eater]], the "first born" of the dragons.

* The Dragon Element in the ''VideoGame/MonsterHunter'' games is the best one against Elder Dragons and the vast majority of weapons carrying Dragon Element are made from Elder Dragons to begin with. Further, the Dragon Element is stated by the devs to deal damage by attacking the mind. Elder Dragons are by far the most intelligent of monsters, and thus the most vulnerable.

* In ''VideoGame/CastlevaniaOrderOfEcclesia'', the Dominus glyphs, which are required to kill Dracula in this particular game, are made from Dracula's own power.
* In ''[[VideoGame/GensouNingyouEnbu Touhou Puppet Dance Performance]]'' the titular puppets can only be harmed by other puppets.
* Implied in ''VideoGame/TronTwoPointOh''. In that universe, human "Users" digitized and sent to {{Cyberspace}} are almost {{Physical God}}s. With one corrupted User unleashing a ZombieApocalypse over multiple computer networks, and the people behind ''him'' about to upload an army of mercenaries to conquer the computer world so they control the human one, [[BenevolentAI Ma3a]] resorts to this logic and uploads the protagonist in desperation.
* {{Downplayed|Trope}} in that a ''Videogame/CustomRobo'' commander can technically be defeated by relentless carpet bombing, but as robos become cheaper and more widely available robo commanders become the only economical means of combating other robo commanders, especially in densely populated areas. Then came, Rahu, which can ''only'' be beaten by robo commanders and is only beatable at all because, [[OnlyTheAuthorCanSaveThemNow for reasons no one can explain]], the world destroying menace decided to start using a robo. A [[NerfArm toy robo]] rather than, say, a military grade one.
* In ''VideoGame/TokyoMirageSessionsFE'', Mirages can only be defeated by the power of another Mirage. Fortunately, some of the Mirages are willing to lend their power to humans, making them Mirage Masters.

* The [[EldritchAbomination Foreigner class]] of ''VideoGame/FateGrandOrder'' is super effective against Berserkers and resists them, and the only way to deal double damage to them is to either use an Alter Ego or another Foreigner.
* In ''VideoGame/FireEmblemAwakening'' the last act of the game is spent finding a way to stop Grima, the ''BigBad'' of the game. Your party goes to a shrine to [[BigGood Naga]] in order to perform an awakening ceremony to hopefully give the [[SwordOfPlotAdvancement Falchion]] the power to slay Grima. However, Naga reveals after the ceremony that slaying Grima with the Exalted Falchion will only put him into a 1000 year sleep, and only his own power is strong enough to truly slay him. [[spoiler:This causes the Avatar to realize that since they were supposed to be the Fell Dragon's vessel, they can also tap into his power, and thus permanently kill him, at the cost of their life.]]
* ''VideoGame/TheWitcher3WildHunt'': Unless a Higher Vampire is finished off by another Higher Vampire, it will regenerate any injury. However, that regeneration can take decades or centuries in case of serious damage, so humans can still ''defeat'' Higher Vampires.
* ''VideoGame/GodEater'': The Aragami are nigh unstoppable monsters made from Oracle Cells that can devour anything in their path. To fight them, humanity resorted to infusing people with Oracle Cells to make them part Aragami and armed them with weapons made of Oracle Cells that essentially ''eat'' the Aragami.
* In ''VideoGame/ValkyriaChronicles'', Selvaria Bles is a Valkyria whose powers make her a seemingly unstoppable warrior who singlehandedly turns the tide of battles. The only person who manages to defeat her with her Valkyria powers active is [[spoiler:Alicia]], who is also a Valkyria. Selvaria does, however, turn off her Valkyria powers later to fight fairly.
* In ''VideoGame/RuneScape'' there are two ways to definitely kill a god: using an Elder Artefact from TheOldGods, or a WaveMotionGun fueled by divine energy.
* The Mortal Blade in ''VideoGame/SekiroShadowsDieTwice'' can [[ImmortalBreaker kill immortal creatures]], but drawing it from its sheath kills you on the spot. As such, only an immortal can actually ''use'' the thing; fortunately, Sekiro qualifies.
* ''VideoGame/RType'': The series indicates that the only weapon that is truly effective against [[BigBad the Bydo]] is the Force Device, a semi-controllable pod that can be attached to either the front or back of the player's ship. The big secret of the Force Device's construction is that it contains an embryonic Bydo lifeform as its core, and the source of its power. Thus, only the Bydo can truly harm the Bydo.
* Used to justify being able to play the titular {{kaiju}} in the single-player campaign of ''VideoGame/GiantsCitizenKabuto'': [[spoiler:After inadvertently freeing Kabuto to rampage over the ShatteredWorld whilst defeating her mother at the end of her campaign, Delphi the Sea Reaper sorceress uses a shard of the magical Kabuto Stone to transform into a copy of Kabuto, in hopes of this making her strong enough to defeat it.]] [[spoiler:Played with, in that whilst Delphi does eventually throw down with Kabuto in her transformed body, she only [[FissionMailed knocks it out briefly and is then defeated when it wakes up]], forcing Baz the Mecc to kill Kabuto by [[GroinAttack shooting it in its groin-mounted weak spot]].]]

* Played with in ''VisualNovel/FateStayNight'' and related works. [[MadeOfMagic Servants]] are said to only be vulnerable to other Servants, but while they are immune to conventional methods of attack (including military hardware up to and including nuclear bombs), in reality any ability infused with magical energy should be able to harm them. In practice, however, Servants are so superhuman that there are extremely few modern magi capable of actually landing a hit on them, meaning that the only way to reliably harm a Servant is through another Servant. Rin claims that even a paper knife can harm one, but only as long as it's wielded by a Servant and infused with mana. That being said, it's entirely possible for a magus to harm a Servant under the right conditions; Rin was able to claim one of Berserker's twelve lives by catching him off-guard with her magical jewels, [[spoiler:and Shirou's copies of legendary weapons allow him to fight Servants for a limited time and even defeat them]].
* Also played with in ''VisualNovel/DiesIrae''. While killing an Ewigkeit user is doable in theory for a normal human, in actual practice it is nigh impossible. This is due to the way Die Ewigkeit works as it gives it's users effectively extra lives on top of a whole host of other abilities. Thus the only really effective way to kill one is to use weapons that take "several lives on each use", and normal such weapons like bombs and nukes just aren't practical. Hence why Ahnenerbe exists, weapons wielded by Ewigkeit users, as they attack the soul directly and can take all those extra lives with more limited attacks. The only known instance of a normal human killing an Ewigkeit user was [[spoiler:Shirou killing Wilhelm at the end of Kasumi's route]], and that relied on a very specific loophole created by the users own powers.

* The titular {{Mon}}s of Webcomic/BattleKreaturez are protected by invisible {{ReinforceField}}s that spike in response to duress, making them NighInvulnerable. Compounding this, they also have a HealingFactor that allows them to recover from most injuries. This means a rampaging Kreature can only reliably be stopped by another Kreature, necessitating the art of Kreature Taming.

* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'': In "[[Recap/MyLittlePonyFriendshipIsMagicS7E19ToChangeAChangeling To Change a Changeling]]", Pharynx uses the StopHittingYourself approach to defeat the [[NighInvulnerable Maulwurf]].
* ''WesternAnimation/ThePiratesOfDarkWater'': In one episode, Ioz is captured by {{Ghost Pirate}}s. Tula and Ren try to rescue him, but any attack they try just passes through the pirates and Ioz's chains, while the pirates can hurt them. Tula comes up with a way to temporarily turn Ren into a ghost so that he can fight back and save Ioz.
* ''WesternAnimation/FinalSpace'': Implied in "The First Times They Met" with the evil [=KVN=]s. They are stated to be nearly indestructuble, which is demonstrated throughout the episode, but towards the end the main KVN easily kills the last one himself by [[AndShowItToYou punching right through him and tearing out a vital heart-like component]].

SubTrope of MutualDisadvantage. SuperTrope to MagicMustDefeatMagic. An opposite of TacticalRockPaperScissors where each type of combatant has some other capable of [[CurbStompBattle curb stomping]] it. However, this can be a subtrope of ElementalRockPaperScissors if an element happens to be weak against itself. Compare BeatThemAtTheirOwnGame, HoistByHisOwnPetard, and SummonBiggerFish. Contrast LikeCannotCutLike and CounterpartArtifacts.

* In ''TabletopGame/DungeonsAndDragons'' 3rd edition and 3.5, creatures with damage resistance have their natural weapons (if existing) able to pierce that same resistance, so every creature is capable of killing its own species.

** The director of ''Anime/MobileSuitGundamSEED'' outright said that "Only a Gundam can beat a Gundam" was part of the series' design philosophy. In this case it was aided by the fact that most Gundams use Phase Shift Armor, which is immune to physical damage, meaning that only beam weapons (like those wielded by Gundams; otherwise beam weapons are ship-mounted weapons that are too large for a mobile suit to carry and can't be aimed fast enough to be effective against agile mobile suits) can hurt them. It's not until late in the series that miniaturized beam weapons are suitable for mass production, and even then the Gundams have defenses against them (albeit less comprehensive than their defense against projectile weapons) that ordinary mobile suits lack.

* The Imperial Weapons from ''Manga/AkameGaKill'' are guaranteed by fate to kill the user's target- unless said target also has an Imperial Weapon, in which case a battle will take place where one user is destined to die.

** Gundams in ''Anime/MobileSuitGundamTheWitchFromMercury'' are suits with a "Permet" BrainComputerInterface that grants incredible reaction times and a overwhelming swarm of {{Attack Drone}}s. Their GUND format would have become the standard decades earlier if [[DeadlyUpgrade the damage they do to their pilots]] hadn't gotten them outlawed. After Elan piloting the Gundam Pharact soundly defeats Guel, an AcePilot in a non-Gundam AceCustom, he states that only a Gundam can defeat another Gundam. We're only shown to the contrary when a Gundam is heavily outnumbered and/or faces an anti-Permet PowerNullifier--and the Aerial specifically can [[ScissorsCutsRock outright ignore the latter]] by increasing the intensity of its system. Eventually, it becomes clear Aerial specifically [[OneHeroHoldTheWeaksauce has overcome the limited and drawbacks of other Gundams]], putting it in a class as its own.

->''"{{Magic must defeat magic}}!"''

* In ''LightNovel/{{Baccano}}!'', the only way an immortal can die is to be [[IdentityAbsorption absorbed]] by another immortal.

* ''Fanfic/AbraxasHrodvitnon'': In this Franchise/MonsterVerse fanfiction, Colonel Foster thinks the ''Heroic Menace vs. Evil Menace'' form applies when [[Characters/AbraxasHrodvitnonTitansAndOtherCreatures the Many]] emerge as a threat, surviving Monarch and the Russian military's initial attempt to exterminate them, and the Many are fought by Godzilla and his allies.

* In ''WesternAnimation/TheIncredibles'', Syndrome's Omnidroids are [[NighInvulnerable so tough]] that only their own claws can pierce their shell. Mr. Incredible beats the first one by climbing inside so that it attacks itself to get at him. [[spoiler: In the climax, Bob realizes that he can use its recently detached claw as a spear to stop the Omnidroid terrorizing their city.]]

** Gundams in ''Anime/MobileSuitGundamTheWitchFromMercury'' are suits with a "Permet" BrainComputerInterface that grant incredible reaction times and a overwhelming swarm of {{Attack Drone}}s. They would have become the standard decades earlier if [[DeadlyUpgrade the damage they do to their pilots]] hadn't gotten them outlawed. After Elan piloting the Gundam Pharact soundly defeats Guel, an AcePilot in a non-Gundam AceCustom, he states that only a Gundam can defeat another Gundam. We're only shown to the contrary when a Gundam is heavily outnumbered and/or faces an anti-Permet PowerNullifier--and the Aerial specifically can [[ScissorsCutsRock outright ignore the latter]] by increasing the intensity of its system.

* Zig-zagged in the ''Franchise/{{Gundam}}'' franchise: Sometimes Gundams can only be defeated by Gundams, while other times any sufficiently advanced mobile suit can potentially defeat one.

** In ''Anime/MobileSuitGundam00'', Celestial Being's Gundams are several orders more advanced than the forces of Earth's militaries, particularly in their use of the GN Drive solar furnace which grants nigh-infinite power. At one point all three of the world's superpowers devote nearly their ''entire'' armies, including specialized anti-Gundam units with souped-up mobile suits and the most elite pilots, just to take down Celestial Being's four guns. The best they can do is constantly attack the Gundams until their pilots are exhausted by the nonstop fighting; the machines themselves are completely unharmed. Their strategy collapses when [[BigDamnHeroes three more Gundams, whose existence was completely unknown before, show up on the battlefield]]. Late in the first season, the Earth forces are handed a supply of GN Drives and a mobile suit designed to use them, which results in their finally being able to fight the Gundams on equal footing. By the time of the second season, the new Earth Sphere Federation has mass-production machines that outclass the original four Gundams in a straight fight...which, conveniently, is when the MidSeasonUpgrade[=s=] roll out.
** ''Anime/MobileSuitGundamTheWitchFromMercury'': After Elan piloting the Gundam Pharact soundly defeats Guel, an AcePilot in a non-Gundam AceCustom, he states that only a Gundam can defeat another Gundam. However, Episode 9 shows Elan to be not entirely correct, as Suletta and her Gundam Aerial are put on the ropes after being outnumbered six-to-one and facing a weapon designed to shut down Gundams. Even after getting a HeroicSecondWind and trashing five of her opponents in quick succession, the sixth would've beaten her if Suletta's own teammates hadn't gotten one last shot in to save her.

* ''WesternAnimation/{{Chaotic}}: Creatures from the spirit lands who are in their spirit form cannot be harmed by anything except for other creatures in spirit form. The downside is that creatures from the spirit lands can only exist outside of the spirit lands for a limited time unless they take on a physical form.

* Franchise/MonsterVerse: The Menace vs. Menace kind, mainly ''Heroic Menace vs. Evil Menace''. Although the government and military would much rather attempt killing [[Characters/MonsterVerseKaiju the Titans]] on their terms using manmade weaponry, the reality is that MilitariesAreUseless against these gigantic, ancient, borderline-EldritchAbomination animals; and whether humans admit it or not, humanity is ultimately reliant for survival on the continued existence of Protector Titans such as Godzilla and Kong, who keep the non-Alpha Titans in check via AsskickingEqualsAuthority and who will duel and defeat the more threatening Titans such as Ghidorah and others, with the government's and Apex Cybernetics' attempts to find a way of reaching Godzilla and Kong's power levels always backfiring horribly.

* ''VideoGame/{{Destiny}}'': Downplayed. [[RealityWarper Paracausal entities]] defy the laws of physics by definition, making them extremely difficult to kill by conventional means -- it can be done, but generally requires MoreDakka and ThereIsNoKillLikeOverkill. Therefore, the most reliable way to kill a paracausal being is with another paracausal being, who can throw punches in the same metaphysical weight class. This is how Guardians are able to kill {{Eldritch Abomination}}s and {{Physical God}}s despite being a bunch of self-trained MildlyMilitary irregulars, and likewise how Guardians, whose powers are supposed to make them [[OneManArmy one man armies]] against purely causal foes, tend to die in droves against the same. It's either that or somehow separate them from their paracausality, turning them into regular flesh and blood.

** ''Anime/MobileSuitGundamTheWitchFromMercury'': After Elan piloting the Gundam Pharact soundly defeats Guel, an AcePilot in a non-Gundam AceCustom, he states that only a Gundam can defeat another Gundam. However, Episode 10 shows Elan to be not entirely correct, as Suletta and her Gundam Aerial are put on the ropes after being outnumbered six-to-one and facing a weapon designed to shut down Gundams. Even after getting a HeroicSecondWind and trashing five of her opponents in quick succession, the sixth would've beaten her if Suletta's own teammates hadn't gotten one last shot in to save her.

* Similar to ''Pokémon'', the Dragon Element in the ''VideoGame/MonsterHunter'' games is the best one against Elder Dragons and the vast majority of weapons carrying Dragon Element are made from Elder Dragons to begin with. Further the Dragon Element is stated by the devs to deal damage by attacking the mind. Elder Dragons are by far the most intelligent of monsters, and thus the most vulnerable.

* In ''Fanfic/JWITCHSeason1'', it turns out that in addition to his canonical weakness to onions, Tarakudo can only be injured by [[CastingAShadow shadow powers]] like his own. [[spoiler: This gives Jade an advantage over him when she becomes the [[SixthRanger Guardian]] of [[DarkIsNotEvil Shadows]].]]

** [[NukeEm Nuclear warheads]] and [[ComicBook/IncredibleHulk the Hulk]] also work, but those tend to be more trouble than they're worth.