->'''Darth Vader:''' He is here.\\
'''Grand Moff Tarkin:''' Obi-Wan Kenobi? What makes you think so?\\
'''Darth Vader:''' A tremor in the Force. The last time I felt it was in the presence of my old master.
-->-- ''Franchise/StarWars: Film/ANewHope''

Suppose [[MagicAndPowers magic, ki,]] or PsychicPowers exist, and that there are people who possess these powers. Naturally, [[PowerLevel how strong]] a given person is with these abilities will be a big factor in the plot, both in the [[SuperWeight ass kicking scale]] and in terms of how characters act and react to each other. But how can writers convey that to viewers? Sure, generally the rule is "show, don't tell", but what if a given character's psychic powers are to pinch shut the carotid artery? Or their SupernaturalMartialArts can crack a planet in two? Having them remind viewers ''"LuckilyMyPowersWillProtectMe"'' gets old fast. And you can't very well have them [[GoodThingYouCanHeal show the power off every time they appear]] so new viewers can get clued in, just imagine what that'd do to the SpecialEffects budget!

So instead writers will give these characters the secondary (or primary) ability to sense each other's power, much like internal StatOVision that is represented with [[ColorCodedForYourConvenience conveniently color-coded]] AuraVision. Typically, TheEmpath or someone with a [[MySignificanceSenseIsTingling Significance Sense]] or SpiderSense will be able to tell the raw PowerLevel of an opponent, what brand of magic they use [[DetectEvil (especially if they're evil)]] and the like. Expect them to intone, ''"TheForce is strong with this one,"'' or a variation when a powerful enemy draws near; especially common is for the sensor to intone ''"[[ReadingsAreOffTheScale Such oppressive evil power!]]"'' before [[FaintingSeer fainting or falling]] to his knees in fear.

This can result in one being a WeirdnessMagnet.

It's practically a requirement for any {{Shonen}} {{Anime}} or {{Manga}} that at least one person can do this (often a {{Mentor}} and someone else in the hero's group to take over when the MentorOccupationalHazard kicks in), especially right before a climactic battle. Western media may use CowerPower, a GameFace or other methods to show this off.

Compare KillingIntent, which can have similar applications but is more about danger level than power level. When one's Strength with the Force is pretty much a guarantee of victory in a fight, it's MyKungFuIsStrongerThanYours.

The TropeNamer is ''Franchise/StarWars: Film/ANewHope''.
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!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* ''Manga/ElfenLied'' of all things has this; Diclonii can sense each other's presence out to a certain undisclosed range, accurately enough to positively ID the other diclonius through this sense alone if they've met in person before. [[spoiler: Well, mostly. Strangely, Nana cannot sense Nyuu, but when Nyuu pops back into Lucy, Nana IMMEDIATELY picks up on it, despite being a good distance away.]]
** It actually makes sense if you consider Nyu a [[{{Depower}} depowered]] state of Lucy.
** In the manga, the Unknown Man takes advantage of this in the most horrific way possible. [[spoiler: [[AndIMustScream He rigs up a limbless Diclonius girl]] into a backpack-sized contraption to use as a Diclonius detector. After having had his way with her, [[{{Squick}} of course.]]]]
* In ''Manga/{{Bleach}}'', Soul Reapers (and other spirit creatures such as Hollows) can detect the level of spiritual pressure (PowerLevel) another creature has. Sufficiently great differences between the sens''ee'' and the sens''or'' can involve side effects like weakness, paralysis, and fear. [[spoiler: There are cases where an individual is so powerful their reiatsu cannot be sensed at all, like Aizen in his final stage of evolution. [[BeyondTheImpossible This baffled everyone.]]]]
* ''Anime/DragonBallZ''. Lots of times. Notably, all the races affiliated with Freeza do not know of this ability or how to use it, and instead rely on mechanical devices which prove largely unreliable since the protagonists' {{Power Level}}s fluctuate naturally and can be consciously pushed up or down. Once the PowerLevel numbers start getting out of hand, the series goes back to using this full-time. This proves to be a drawback in the Android Saga, since the mechanical / cyborg villains are undetectable in this way.
* ''Franchise/{{Gundam}}'' has Newtypes who have this ability.
* ''Manga/{{Saki}}'' is a manga about {{Mahjong}}, and therefore, strong enough mahjong players can feel the auras of other strong mahjong players.
** In one chapter of the spin-off ''Manga/{{Saki Achiga-hen}}'', the main characters (a different group of girls) pass Saki in a hallway at the competition venue. Their coach (said to have been the strongest player in the history of their school) and one of their most skilled players freeze up in terror as she gets closer, despite not even knowing who she is. The rest of the main characters, including [[GenkiGirl Shizuno,]] have no idea what's going on...then Shizuno, despite being the worst player on the team, feels a chill run down her spine when Saki passes right by her.
* ''Manga/SoulEater''
** Anyone who has "soul perception" [[ExactlyWhatItSaysOnTheTin can thus see the souls of living people]]). In the anime, this is shown the viewer via a ColorCodedForYourConvenience (blue = natural, red =kishin, purple = witch or misc.) glowing ball of proportional size to their power (with "accessories" for different characters).
** There are degrees of soul perception. Some, like Stein, can pick up on individual characteristics and emotions, others can sense when people are lying and see through the soul protection skill of witches (BJ), or extend their 'sight' over large distances (Azusa's clairvoyance). Maka can detect souls over wide areas (though not to Azusa's level...yet), picks up on emotions, ''and'' is implied (the Baba Yaga arc ''might'' have confirmed it?) to be good enough to see through Soul Protect.
** Maka frequently comments on the soul of whoever she is fighting, and Gopher for one is not impressed with her "peeping". The one time she was shocked with the results was early on when she sensed a true witch's soul for the first time. Considering it was Medusa, she had every reason to be scared.
* In ''Manga/FullmetalAlchemist'', the Xingese characters can feel the flow of the planet's natural energy, which is useful for [[DetectEvil finding]] homunculi, who feel like [[PoweredByAForsakenChild several dozen people]] in one body.
* Various characters, usually with the help of Millennium Items, in ''Anime/YuGiOh''.
* Judai gains this power in Season 4 of ''Anime/YuGiOhGX''. His spirit partner Winged Kuriboh seems to possess it from the beginning.
* Most {{ninja}}s in ''Manga/{{Naruto}}'' can feel the [[LifeEnergy chakra]] of others while fighting them up close, but the ability to detect and gauge it from a distance is very rare. Karin, Fu, Ao, and C are some examples. Karin has also shown to use it to become a LivingLieDetector and can hide her chakra from other sensors (but can't sense herself when doing this), but it's unknown if anyone else can. Most of them also showed the ability to tell when someone else was sensing ''their'' chakra.
** [[SuperMode Sage Mode]] also grants its user the ability to sense chakra from a distance, likely because the power involves ''controlling'' the natural chakra around him. Somehow, after gaining this power Naruto is immediately able to identify individual people by their chakra from beyond visual range, despite (since this was the first time he ever used the ability) having no pre-existing frame of reference as to what each of his friends' chakra should "feel" like.
** Kisame's [[EmpathicWeapon Samehada]] can apparently sense/smell especially large bodies of chakra. This is possibly a reference to shark's ability to find prey with electrolocation.
*** Later when Naruto enters his new kyuubi form, he can [[DetectEvil sense negative emotions]], thanks to nine-tails.
** The Hyuuga clan with their Byakugan can do this see chakra.
** [[TeamPet Akamaru]] can [[TheNoseKnows smell chakra]].
** Some members of the Yamanaka clan can do this.
** Pain could detect a person's strength if it stepped into "his" rain.
* In ''LightNovel/FullMetalPanic'', a variation of this can be found with Sousuke. He's shown to have a sort of sixth sense, in that he actually has the ability to sense "killing intent" in the air, and can somehow know when there are enemies that want to kill him. He demonstrates this ability several times, though one of the more pronounced instances can be found in the later novels. Tired, wounded (having had [[spoiler: a huge portion of his liver blown out of him by a shotgun]]), and confined to a hospital bed, he was shown to be able to sense a bunch of soldiers sent to kill him, and therefore managed to lay a trap for them by the time they arrived.
** Apparently, it only works for when people are out to kill him specifically. [[FridgeLogic If this worked on people trying to kill someone else,]][[HilarityEnsues the show wouldn't have most of its comedy.]]
** The fact that he's extremely paranoid [[ChildSoldier ( for good reason, due to his history)]] probably helps.
* In ''Anime/CodeGeass'', it appears that those who possess a Geass Code or are in the Sword of Akasha can sense Geass users.
* ''Manga/{{Claymore}}'': Yoma, Claymores and Awakened beings can sense each others presence and the amount of yoki. However, some of them can mask their aura to appear far weaker than they are (Riful) or even completely suppress it so only direct contact with their body will reveal that they are anything other than human (Priscilla). The Claymores have a pill with a similar effect. This is the only reason anyone survived the Northern Campaign.
* In ''Manga/OnePiece'', Fukurou of CP-9 can do this, albeit in an unorthodox fashion. He [[{{Acrofatic}} hurls himself bodily]] at his teammates and receives a deflecting punch or kick. Then he stands up and rattles off their respective power levels.
** Silvers Rayleigh also apparently uses this to predict that there were over five hundred beasts on the island of Rusukaina that could beat Luffy, by means of [[SpiderSense observation haki]]
* In ''Manga/MagiLabyrinthOfMagic'', Yunan, Scheherezade, Matal Mogamett, and Ren Gyokuen immediately realized that a miracle occurred when TheChosenOne and resident BigGood Sinbad was born.
* Ryou from ''StrawberryShakeSweet''. If you're a lesbian, she can [[{{Gaydar}} see it]] in your aura. Heck, she can even tell ''who'' you're gay for:
-->'''Ryou:''' I've sensed the aura of a woman who is in love with her same-sex sempai two levels above her in the company.
-->'''Julia:''' Wow, that's... really specific.
[[/folder]]

[[folder:FanFic]]

* FanFic/DreamingOfSunshine features Shikako, who is a chakra sensor to the point that she can see through disguise jutsu of people she knows well, gauge and enemie's aproximate strength, and detect lies.

[[/folder]]

[[folder:Film]]
* ''StarWars''. Vader [[TropeNamer names the trope]] when he's chasing Luke down the Death Star's trench, and finding himself unable to get a solid lock. Vader also senses Obi-Wan's presence aboard the Death Star.
** [[ThePhantomMenace Decades earlier]], Qui-Gon had sensed Anakin's potential.
** In ''RevengeOfTheSith'', Palpatine [[CallForward quotes this line]] when he dubs Anakin "Lord Vader" for the first time.
* ''Film/XMenTheLastStand'' had Callisto who could detect other mutants and ascertain their relative "power-levels" on a 1-5 scale. Only one level 5 has ever existed, and when she tells Magneto that she just became aware of a "level 5", he immediately knows that she refers to Jean Grey's "Phoenix" personality.
[[/folder]]

[[folder:Literature]]
* Female channelers in ''TheWheelOfTime'' can always sense the strength of fellow female channelers, and perceive a glow around females actively using magic. All channelers can sense their own gender's magic in use, and spells are possible to sense the other gender's. Males channelers get goosebumps when females close by are using magic. There are also techniques to hide both ability and active use.
* Lampshaded by Tyria Sarkin in ''[[XWingSeries Wraith Squadron]]''. She once says of herself, "The Force is weak in this one." She's Force-Sensitive, the last of the Antarian {{Ranger}}s from Toprawa, but her Force powers are weak, and she feels overwhelmed by what she has to live up to.
** In ''Literature/GalaxyOfFear'', Tash Arranda can feel the Force in Darth Vader. When she meets [[VideoGame/DarkForcesSaga Jerec]] she recognizes [[DetectEvil the same sort of feeling]] in him but thinks he's not as strong.
* Wizards in ''Literature/SeptimusHeap'' can feel somebody's else's Magykal powers, which makes Marcia feel Septimus's Magyk long before he's revealed. [[{{Muggle}} Jenna]] feels his Magyk too in the first book.
[[/folder]]

[[folder:Live Action TV]]
* Telepaths in ''Series/BabylonFive'' can usually sense each others' proximity. Similarly, Lyta was able to tell that Sheridan had also been TouchedByVorlons, but she didn't clue into it until Sheridan said something that only Kosh would have said. The human Psi Corps actually uses a rating system of P1-12 to quantify how powerful a given telepath is. P13 or higher are hypothetical, [[spoiler: or Lyta Alexander]]. It is unclear if other species have equivalent rating systems.
[[/folder]]

[[folder:Tabletop RPGs]]
* ''[[VampireTheRequiem Vampire: The Requiem]]'' has Blood Potency and The Beast. The higher a vampire's blood potency, the more blood they can store and spend, and the harder they are to affect with negative powers. As BP rises, [[EnemyWithin The Beast]] gets stronger too, so every time a pair of vampires meet, their Beasts will "confront" each other, with the stronger of the two trying to incite an UnstoppableRage in its host, and the weaker one to make its own run away screaming.
* ''[[PrometheanTheCreated Promethean: the Created]]'' has a similar rule -- "Azoth [the "Divine Fire" that gives Prometheans life] calls to Azoth." On the plus side, whenever two Prometheans are within a certain distance, they can feel their Azoth tugging towards each other. On the minus side, so can the [[CameBackWrong Pandorans]]...
* The Detect advantage in {{GURPS}} is this in a nutshell
* [[DungeonsAndDragons AD&D]] has spell Wizard Sight, used to discern arcane and divine casters and appraise spellcasting potential, and see magical auras of objects instantly and certainly (unlike "detect magic" probe).
[[/folder]]

[[folder:Videogames]]
* Keyblade users in ''KingdomHearts'' can sense light and darkness of peoples hearts as well as sense the hearts of people familiar to them. Only Terra and Aqua make use of this regularly however as it requires quite a bit of training. Since Sora hasn't gotten official training he's only made use of it once so far. [[spoiler: He could sense that "Ansem" was actually his best friend Riku but not until Kairi hinted to close his eyes and feel with his heart.]]
* ''{{Lufia}}'' seires's Spiritual Force, which both heroes and big bads lampshade whenever they meet. By the DS remake, detection and unleash of Spiritual Force can be done even by oldmen.
* In the beginning of ''VideoGame/StarWarsTheForceUnleashed'', Darth Vader defeats Kento Marek. Vader tells Kento that he can sense someone far more powerful nearby and demands to know where Kento's master is hiding. Kento claims that Vader killed his master years ago. Vader is surprised when he discovers that the powerful Force-user he sensed was Kento's son Galen (the player character), a little boy.
[[/folder]]

[[folder:Webcomics]]
* Sensei Greg in ''Webcomic/ElGoonishShive'' [[http://www.egscomics.com/?date=2002-07-13 feels]] active magical forces (including shapeshifting) around. [[spoiler:Adrian Raven]] discerns the magical potential in people.
[[/folder]]

[[folder:Web Originals]]
* Boris "The Bloodhound" Lydecker from the ''GlobalGuardiansPBEMUniverse'' is a reporter for ''Capes and Cowls'' magazine (imagine [[http://www.usmagazine.com/ Us Magazine]] if it concentrated on metahumans rather than celebrities). He is, himself, a metahuman with the sole power to detect other metahumans, including he ''general'' nature of their powers and power level (along the lines of "something to do with fire... but wow does he have a lot of it"). His usual assignment is to "out" superheroes who haven't revealed their [[SecretIdentity real names]] to the public yet. Naturally, he's not well liked in the superhero community.
** Mentalists in the GGU can always sense other mentalists whenever they get into close proximity; ironically, it is the least powerful and least experienced telepaths who are sensed more strongly because they have a harder time keeping their "psychic leak" as it is called, under control. Powerful telepaths, or very experienced one yet only mildly powerful ones, only leak a little.
** Wizards and other mystics in the ''GlobalGuardiansPBEMUniverse'' can automatically detect the presence of other wizards and mystics, but they can only detect each other's power level if the other mystic is either currently spellcasting or if they voluntarily "project their aura of power", thus intentionally advertising just how powerful they are.
[[/folder]]
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