Lightsabers can cut through pretty much anything. Except another lightsaber.
"In the presence of many death scythes, the motto that a death scythe can cut through anything becomes a falsehood."
— Sebastian Michaelis, Black Butler
Nothing can block a weapon made of a magical material — except for another weapon of the same material.
Typically neither weapon will be affected at all; on rarer occasions, both will be destroyed utterly, or pass entirely through each other. The effect is the same in all cases- the phlebotinum weapons effectively cancel each other's usual superiority over opposing weapons, and only a direct hit on the opponent will end the duel... Which is also likely to kill them unless your Implausible Fencing Powers are good enough to disarm them without, y'know, "disarming" them.
Needless to say, a character who thinks they have a Disc-One Nuke in the form of their sword will be very unpleasantly surprised when facing an opponent who can even the odds. They may even get crushed if they've let their skills get rusty by relying on the weapon's power. Such duels tend to prove suitably epic.
A Sub-Trope of Mutual Disadvantage, of the "mutual invulnerability" variety. Also a subtrope of Elemental Rock-Paper-Scissors, where one of an element's defensive strong points happens to be itself. Contrast Takes One to Kill One, when only like can cut like.
Examples:
open/close all folders
Anime & Manga
- Accel World: Incarnate Abilities are this. Only another Incarnate Ability can block them as they'll cut through anything else like butter. This is because while normal attacks are designed by the system, Incarnate Abilities are created by the players' will, essentially futzing with the system parameters until you break 'em. By order of the Kings, they're illegal to use in Brain Burst unless you're attacked by one first. Of course it's also illegal to actually TEACH these techniques to other players, which means when Noumi breaks out his to devastate Cyan Pile, the heroes are stuck having to rely on cryptic advice and vague hints from their friends in order to counter it.
- Battle Angel Alita: Last Order: Monomolecular wire can be stopped by a stick made out of monomolecular material.
- In Black Butler, the death scythes carried by the Grim Reaper dispatch can cut through anything. Naturally, a death scythe can't cut through a death scythe.
- The Severing Crime Edge: No matter how powerful the Killing Good is, it cannot destroy another killing good.
- Beam sabers in Gundam are made up of a superheated Minovsky Particle plasma encased in I-Fields. I-fields cannot block regular matter, so what allows beam sabers to cut through almost anything is the fact that hitting something with your saber is literally letting the plasma of the saber eat through whatever you're trying to cut. When two beam sabers make contact, the I-Fields from both swords are repelling the plasma of the other. As beam projectiles are also made of Minovsky particles, the same principles makes them scatter on contact with a beam sabe or other beam, though for obvious reasons that's less common.
- A rare exception to this is the beam zanber from Mobile Suit Crossbone Gundam; following the description above, the zanber is basically a giant plasma flame without an I-field containing it, and can cut through standard beam sabers by introducing more plasma than their I-fields can handle.
- Beam shields, introduced in the second Universal Century, rely on the same general principle, they're basically a beam saber elongated into a wide plane that can be used to block attacks. Incidentally, if enough force is applied to a beam shield (or enough concentrated pinpoint power in the case of the Variable Speed Beam Rifle), it's possible to collapse it and hit the target behind it.
- Subverted in Mobile Suit Gundam SEED Destiny, the beam sabers in Cosmic Era are formed with Mirage Colloid without the use of I-Fields and they go through each other should they clash. During the fight of the Destiny Gundam versus the Infinite Justice, the Infinite Justice cuts the Destiny's Arondight Anti-Ship Sword in a half when they clash with each other. However, shields can block beam sabers.
- In Guyver, high frequency swords can't cut other high frequency swords, and when two high frequency weapons come into contact with each other, they make a deafening shriek.
- In Naruto, Sasuke can channel lightning through his sword to give it incredible cutting power as well as inflicting paralysis, but both effects are cancelled out when clashing with one of Killer Bee's sword also enhanced (albeit differently) by lightning.
- In Outlaw Star, Gene's caster shells could be blocked by firing another caster shell into them.
- Also subverted towards the finale, as there are some rare caster shells that will have abilities that only activate when blocked by another caster shell.
- In Samurai 7, the daito that the Samurai use can cut through anything from wood to Humongous Mecha... except other daito.
- Played Straight in Shaman King, in that only Oversoul weapons can beat other Oversoul weapons (and Oversoul armor), but subverted when you get a character savvy enough to straight-up break their opponent's weapon, dispelling the Oversoul immediately.
- Gourry's energy blade sword in Slayers is eventually tested against another weapon that was created by the same people. When the two energy blades meet, they shriek. They then actually began to fuse together, and the energy released began to open a door to another dimension, wherein dwelt the god-killing Dark Star.
Comic Books
- Cyclops and Havok from the X-Men are immune to each other's energy projection powers, and being brothers, they are "like" on the genetic level, thus fitting the trope (except Scott and Alex's DNAs seem to deviate at different points, considering how their powers work differently from one another).
- It isn't often brought up often outside of these two but it's established through them that mutants who are genetic siblings are immune to each other's powers.
- Not just siblings, as the cousins Black Tom Cassidy and Banshee are also immune to each other's powers.
- Adamantium can cut through practically anything on Earth except for things that are made of Adamantium. This is the main reason that Wolverine has a lot of foes who use Adamantium weapons or armor, like Cyber and Lady Deathstrike.
- Inverted with vibranium, at least in the Ultimate Avengers animated films. General Nick Fury outright states that aside from a nuclear explosion, the only (solid) matter that is capable of breaching vibranium is... more vibranium. This is something that Black Widow demonstrates by throwing a vibranium star into a slab of vibranium.
Fan Works
- A Certain Droll Hivemind: Yui gets grabbed by someone and immediately shocks them. This does nothing, because the one who grabbed her is Misaka Mikoto, who is literally orders of magnitude more powerful than her. Thankfully, Mikoto of course isn't there to hurt her.
I electrocuted my assailant.
It did nothing. I felt my Electromaster power be totally negated by one vastly superior to mine.
"Don't do that," the original said to me. "What are you doing here?" - One of the rules of magic in The Apprentice, the Student, and the Charlatan:
- The First Fundamental Law is that, no matter how powerful one source is compared to the other, magic cannot pierce or go through magic through natural means. Magic can push other magic back, but it can't go through other magic. Given the author's attempt at having magic operate under quantum physics, it's justified In-Universe by magic automatically snapping to particle state when interacting with other magic. However, enter the magi-gun, which somehow manages to force magic into wave state when around other magic, making all forms of magical shields useless, and it's treated as such a dangerous weapon that the protagonist resolves to have it destroyed when its usefulness has run out.
- It explores the ramifications of this trope a bit, as well. Enchanted clothing by default comes with spell-shielding (though there are specific enchantments that give its article more energy to repel magical attacks, given that magic particles annihilate each other on contact), enchantments have to constantly be repaired after every run-in with magic, and ponies can't teleport through shields, but can teleport around them if it isn't a full encasement.
- The J-WITCH Series: The Samurai Khan's shadow katanas can cut through everything, except Jade's weapons she creates through her shadow magic.
- In the Naruto fanfic Son of the Sannin, Sasuke battles against Karui during the Chunin Exams, both of them using their swords. At one point, the two get into a Blade Lock, with Sasuke using Burning Edge and Karui using Thunder Blade against each other. Karui overpowers Sasuke and breaks his katana, forcing him to bring out his spare one. They get into another blade lock, but this time Sasuke uses the same jutsu as her, and she's unable to break his weapon in the same way.
- Pokémon Wack: In addition to the canon types, Wood, Steam, Magma, Paper, Rubber, Light, Nuclear, Glass, Plastic, and Grease are all types that resist their own.
Films — Live-Action
- In Kill Bill, the only thing that can withstand the cut of a sword forged by Hattori Hanzo... is another one.
- Lightsabers in Star Wars have this property, along with the ability to reflect blaster bolts. Only a small set of non-saber weapons (i.e. electrostaves, Beskar steel) can effectively parry them.
- According to ancillary materials, Sith lightsabers have properties that can occasionally cause the blade they are clashing with to deactivate. This is the Watsonian explanation for why Obi-Wan's lightsaber flickers when he fights Vader in A New Hope.
- More ancillary materials give you the Barab ingot crystal. This crystal, when inserted into a saber, gives it the ability to occasionally flicker and pass through a blocking lightsaber without destroying it.
- The "reflect blaster bolts" property was touched upon in a novel, wherein an alien race was able to defeat Jedi because their blasters (permanently set to stun) had a different frequency. Lightsabers could be tuned to reflect these blaster bolts, but then they were rendered moot against regular blasters.
- Also done in Star Wars RPG games (starting with Knights of the Old Republic); when eventually acquiring a lightsaber, the player will soon find that, rather than the Infinity +1 Sword they may be expecting, it's essentially an upgraded, shiny sword that only chips away heath rather than a Game-Breaker.
- The energy discs in TRON and TRON: Legacy can cut through programs like butter, but will rebound off each other harmlessly. Except at the end of Tron and Sark's last duel, where Sark tries a standard disc-block to deflect Tron's attack, but Tron is so much more skilled that his own disc flies right through Sark's (and Sark's head) as if the latter were wet tissue.
- X-Men Film Series
- In X2: X-Men United, Wolverine and Lady Deathstrike both have adamantium claws/fingernails.
- X-Men Origins: Wolverine:
- Wolverine faces Weapon XI, who has an adamantium katana.
- William Stryker shoots Wolverine in the head with adamantium bullets (which is kinda justified, as a bullet, which is really fast, could have more impact than a blade). Doesn't kill him, but it does give him amnesia — presumably the shock of the impact gave him severe brain damage and his Healing Factor couldn't piece all his memories back together.
- Weirdly subverted in The Wolverine: Wolverine's claws can be blocked by ordinary Katanas, and a superheated adamantium sword is able to cut his claws off.
Literature
- 12 Miles Below: Occult blades produce a blue field that can cut through anything besides other occult material, most obviously other occult blades. In fact, occult blades are basically indestructible while activated... which is a good thing, because it turns out that they're made of pewter, an otherwise extremely soft metal.
- In Harry Potter, Harry's and Voldemort's wands behave quite strangely when they try dueling each other, due to the wands being "twins", having feathers of the same phoenix (specifically, Dumbledore's pet phoenix Fawkes) as their respective cores.
- In the Incarnations of Immortality series, the highly magical Red Sword wielded by War cannot cut through Chrono's hourglass.
- Averted in Sergey Lukyanenko's A Lord from Planet Earth with the planar swords. While a planar (or monoatomic) sword cuts anything, it's similar to a lightsaber in this regard in that it passes through like knife through butter. When two planar swords meet, one will always cut through the other. Which one is determined by the angle of impact and the sharpness of each blade. This completely changes how people fights with these weapons. So no Blade Locks here. Unlike lightsabers, anyone can use a planar sword given sufficient training, and you can get them anywhere, although they're only produced on one planet.
- Played with in Michael Moorcock's Melnibone series; early on, Elric, armed with the runeblade Stormbringer, faces his cousin Yyrkoon, armed with Stormbringer's "sister" Mournblade. True to the trope, Stormbringer—which can cut through just about anything else it comes across—can't do that to its twin blade, and the cousins have an old-fashioned swordfight. As the battle progresses, Elric slowly masters Stormbringer, which has a will of its own; conversely, Yyrkoon allows himself to fall under Mournblade's control, with the result that Stormbringer and Elric neatly overpower Yyrkoon and Mournblade... casting Mournblade into hell, or at least another plane. That part's never really explained clearly.note
- Shardblades in The Stormlight Archive can cut through any non-living substance except other Blades and Shardplate as easily as swinging them through the air (they pass straight through living flesh without leaving a mark, but kill the victim anyway). While Shardplate can only take a few hits from a Blade before shattering, the Blades can parry each other indefinitely without harm. This is because a Shardblade is the physical manifestation of a spren (it's complicated), taking the form of Honor and Cultivations combined Godmetals. Rhythm of War reveals the origins of Plate as well, being made of lesser spren associated with the Spren a radiant is bonded to, again in the form of the Godmetal above. Presumably it can break because it is formed of multiple Spren who can be seperated, compared to the Shardblade which is a single entity.
- The titular Sword of Truth has been known to cut through any weapon or armor — except for one case when a similarly enchanted blade is encountered.
- In the Wings of Fire series, the only antidote for a RainWing's corrosive venom is the venom of a sufficiently close blood relative.
- The Long Ships: Main characters Orm and Toke have andalusian swords, made from steel far superior to what's available to the other vikings. They tend to shatter the swords of their enemies quite a bit, but when the two accidentally cross blades, nothing happens.
- In The Wheel of Time, the Dark One can corrupt and destroy anything in existence — including reality itself — except his own power. The key to the Last Battle is an artifact that lets the hero siphon off some of that power and incorporate it into the seals that bind the Dark One outside the Universe, preventing him from unraveling their magic like he did previously.
Tabletop Games
- Shadowrun. To stop monofilament attacks (e.g. a monofilament sword), wear armor/clothing with monofilament threads woven into it.
- Warhammer 40,000: Played straight in the case of power weapons contacting other power weapons. The disruptive fields surrounding such weapons clash but typically prevent any damage to the physical component of the weapon itself.
- Dungeons & Dragons: In 3.5, Adamantine weapons have the ability to bypass hardness when trying to damage weapons or objects if the material it is made out of has a hardness of less than 20. In turn, Adamantine is the only material (in the core books; supplements added a few others) that has a hardness of 20. On the other hand, Warforged with the Adamantine Laced feat invert this trope: they become resistant to damage from weapons that are not made of Adamantine.
Video Games
- Minecraft: Golden Pickaxes cannot mine Gold Ore — all other non-wooden pickaxes can mine the ore they're made of, but gold, true to Real Life, is exceptionally weak.
- In Super Robot Wars: Original Generation, one of the very few things that can stop Sanger Zonvolt's Colossal Blade is another Colossal Blade, wielded by Wodan Ymir, a man who is Sanger's equal in every way.
- Despite the utterly insane powers of the Red/Blue/Gold Keys of Umineko: When They Cry (including, but not limited to preemptively disallowing any sort of defensive concept) they can clash with each other. Note that in the Tips section it is mentioned that the Keys are limited in power for that Game Board, presumably to stop Dlanor swinging her sword twice and ending the story instantly.
- Pokémon:
- The franchise plays this completely straight but then subverts, and inverts this in its Elemental Rock-Paper-Scissors. Of all the eighteen current types, nine types (Fire, Water, Electric, Grass, Ice, Poison, Psychic, Dark, and Steel) are resistant to their own attacks, two of them are weak to their own attacks (Ghost and Dragon), and the rest only take normal damage from their own attacks. Because of this, certain dual-typed Pokemon can be either weak or resistant to their own types (A Ground/Steel typed Pokemon resists Steel-Type moves, but takes double damage from Ground-Type attacksnote .)
- Several Pokemon have abilities that make them immune to their own type. For example, multiple Electric type Pokemon such as Jolteon, Electrivire, and Zeraora have the Volt Absorb ability, meaning they get stronger when hit by an electric type attack. If these Pokemon met in battle and only had electric type moves, the battle would be a stalemate until all participants ran out of PP and could use Struggle.
- Castlevania: Lament of Innocence has this with the various Elemental types of enemies in regards to the special whips. The Fire, Frost, and Thunder Elementals are immune to the Fire, Ice, and Lightning whips, respectively. Likewise, the Flame and Frost Zombies are immune to the Fire and Ice whips, respectively.
- In Sword of the Stars, Mesonic Torpedoes will go through all Deflector Shields except for Meson Shields.
- In XCOM: Enemy Unknown, alien alloys are extremely durable, making them ideal for armor and weapon designs. But this trope is massively subverted when you produce the Alloy Cannon: it turns out that while alien alloys are difficult to shape into a proper projectile, it's not impossible, and shards of alien alloy traveling at super-high velocity will shred anything (the Alloy Cannon has the highest damage in the game). Flavor text for the weapon also reveals that the alloy's extraordinary toughness, while ideal for use as ammo, resulted in the immediate destruction of the first Alloy Cannon prototypes because the standard materials used for the barrel couldn't withstand contact with the hyper-accelerated alloy shards — the pellets just cut right through the steel and blew the gun apart. Only a redesign that incorporated alien alloys into the barrel itself made the weapon actually viable for production.
- Borderlands: The Pre-Sequel!: Unlike basically every other elemental enemy, Phonic Kraggons don't resist their own element of Shock, instead being like a normal Kraggon, and resisting Fire.
- Red Alert 3:
- Subverted for the most part, as units with specialized damage types (Tesla Troopers/Stingrays, Cryo Legionnaires, etc.) have no problem damaging units of the same type despite being theoretically immune to it.
Tesla Trooper: Insulation won't help!
- The one exception are Desolator troopers, who are immune to toxic weapons. In fact, garrisoning a Desolator inside a building first will make every unit immune to being cleared out by another Desolator as the first negates the damage caused to following units (it's not a Game-Breaker as it doesn't make them immune to other building-clearing methods like molotovs.
- Exploited in Yuriko's mini campaign where she's trapped by cryo-turrets and later attacked by cryocopters. Using an Attack Reflector causes them to freeze up, freeing her.
- Subverted for the most part, as units with specialized damage types (Tesla Troopers/Stingrays, Cryo Legionnaires, etc.) have no problem damaging units of the same type despite being theoretically immune to it.
- Devil May Cry: The Nightmare-Beta was created from the essence of the demon known as Nightmare. Naturally, Nightmare is immune to its lasers when you fight the thing.
Web Animation
- In Monkey Wrench, lythop crystals are sharp enough to cut through practically anything, but when two crystals clash, they produce an energy field which stops them from cutting each other.
Western Animation
- Blackstar has the Star Sword, and the Overlord has the Power Sword — two equally indestructible halves a superweapon called the Power Star (a few years before the Masters of the Universe toys would use the same gimmick).
- Samurai Jack: When Jack first meets the Scotsman, he's surprised to find his nigh-invulnerable sword cannot so much as scratch the Scott's similarly-enchanted weapon. The two spend the entire day fighting, and only succeed in exhausting themselves to the point where neither can lift their swords anymore. When asked what made his sword special, the Scotsman replied "magic runes, laddie". This implies that his claymore, like Jack's katana, is endowed with magical properties, by gods or otherwise. But somehow, Aku was able to break the Scotsman's weapon, something he's unable to do with Jack's.
- In another episode, Aku tries to kill Jack with his own magic katana, but it bounces harmlessly off his skin. Jack informs the villain that since the sword is good, it won't harm good creatures like himself.
- X-Men: The Animated Series: Like in the comic section, cousins Black Tom and Banshee are immune to each other's powers, a fact that causes them to usually settle their differences with their fists. This also sets up an interesting Easter Egg in a later episode when the X-Men find themselves up against X-Factor. Team leaders Cyclops and Havok are quite surprised to find their powers don't work on each other. Of course long time X-fans know why.
Real Life
- Inverted, strangely, in the case of diamonds. Bruting
is a process wherein two diamonds are used to cut each other to desired shapes. In fact, of those materials naturally found in nature, only like can cut like in this case.
- Averted with the Higekiri, a tachi whose legend purports it to have cut another steel blade, to the point where one of its many names is Tomokiri ("Equal Cutter").
- Magnets: The sides with the same polarity will always repel each other.
- Unless brought together by a greater force. Then colliding into each other both chips chunks off (reducing the magnetic power), and reduces the magnetic power further through the interaction of their respective fields.
- This occurs in the sun. Stars basically start off as a collection of high energy protons, which collide with each other to create energy. The problem is, all protons are positive, and therefore, repel. The sun simply isn't hot enough to give the protons enough energy to overcome this propulsion, making it a seeming impossibility under classical physics. Quantum physics shows that protons could 'tunnel' through the repulsive effects of electromagnetism and collide with another proton often enough for fusion to work.
- Even more basic, the nucleus of an atom shouldn't be able to exist if the universe only had the Electromagnetic and Gravitational forces, considering it's basically a dense cluster of protons and neutrons (which add nothing). One of the four fundamental forces of nature, the strong force, keeps them that way.
- This is known as the irresistible force paradox, and dictates that if no one knows what will happen if an unstoppable force meets an immovable object, it's considered self-contradiction.note
- A few military vehicles have a hard time fighting other units of the same type. For example:
- Bombers have a tough time with other bombers since they are focused almost entirely on air to ground combat. In the unlikely event that two enemy bombers meet without escorts they could only try and kill each other with self defense armament. Bombers can carry air to air missiles but are extremely unlikely to mix these with traditional Air to Ground weapons.
- Anti air units have the same problem as bombers in reverse, their primary armament is focused on anti air and can't attack other ground units. If two mobile SAM launchers had to fight each other, the crews would have to use small arms to try to disable the enemy. Which is why by the end of the Cold War some designers have started to build in at least some ground-to-ground capacity into the SAMs — this wouldn't be their most efficient use and would waste the enormously expensive missiles, but it could help in a pinch. For example, during the 2008 Russia-Georgia conflict, a Georgian corvette was sunk by a Russian Osa SAM, which has an optional ground-to-ground mode.
- Submarines couldn't effectively attack each other until the invention of the guided torpedo during the cold war. Before then they would have both had to surface and agree to a gun duel, which never happened anyway.
- Well, except for that one time... And even beyond that, there were instances of one submarine getting a drop on another surfaced submarine. Subs didn't spend all of their time submerged, mainly because they couldn't, they had a limited supply of air and had to conserve it, so they would surface when traveling in relatively safe areas. The aforementioned HMS Venturer, which is famous as the only sub to have sunk another sub in combat while both were submerged, was also responsible for the sinking of two U-Boats, U-771 and U-864(The one where they were both submerged). Both were sunk with torpedoes. Actually, there hasn't been an instance of one sub intentionally sinking another sub since the Second World War, and no instances of them doing so with guided torpedos,note as the Venturer used unguided torpedoes and the crew manually calculated U-864's position.
- Well, except for that one time...
- A few of the last generation of armored cruisers were "armored above their guns", I.E. they were meant to withstand punishment from larger shells than they carried. If two such ships met each other in combat, they would be unable to inflict critical damage to each other (well they could, but it would take awfully long time).
- Likewise, the "heavy light cruiser" was a concept a generation later that resulted in a similar situation, cruisers that could not penetrate the other's armor. Downplayed in that the idea was that while such ships couldn't reliably sink each other, they could severely maim each other. Most of the important bits to keeping a ship fight worthy are outside the armor box. A victorious heavy light cruiser would have the enemy limp away, where the loser could then be chased down and destroyed (since the loser probably would have lost a lot seaworthiness, and therefore speed, in the beat down) by an actual heavy cruiser, a battleship, destroyer torpedoes, submarines, or aircraft.
- And then there was the Battle of Hampton Roads during the American Civil War, the highlight of which was the shootout between the ironclad warships CSS Virginia (formerly the USS Merrimack) and the USS Monitor. After three hours of shooting at each other, neither ship could seriously damage the other and both ships withdrew.note
