History Main / PsychicBlockDefense

* Learning to erect mental shields is an essential element of {{training|TheGiftOfMagic}} [[PsychicPowers Gifts]] in the ''Literature/HeraldsOfValdemar'' series, especially [[{{Telepathy}} Mindspeech]] and [[TheEmpath Empathy]], chiefly to prevent PowerIncontinence but also to defend your thoughts against other Gifted (who often don't have malicious intent, but may simply allow stray thoughts to leak through their own shields). Using the Gift is a matter of lowering enough shields to accomplish your purpose, and otherwise they're kept raised as a matter of habit. Rarely, characters are encountered who have natural shields impervious to all but the strongest mind probes; quite often these characters are not Gifted or otherwise special.

* In the ''Literature/{{Lensman}}'' series, both mechanical and mentally generated thought screens are very common. Mechanical thought screens will stop telepathic probes by minds of second stage and lower but will barely even slow down the probes of third-stage minds. Mechanical screens are also vulnerable to being physically switched off or sabotaged, either by the hostile telepath or by an unprotected creature that the hostile telepath mentally controls. Mentally generated thought screens are immune to being physically switched off but can be penetrated by more powerful or more advanced minds.
* In ''Franchise/{{Mistborn}}'', an Allomancer burning Copper becomes immune to EmotionControl by other Allomancers burning Zinc or Brass, and both they and everyone near them become undetectable by those [[PsychicRadar burning Bronze]]. WordOfGod states that both effects would be equally effective against similar effects from other magic systems of ''Literature/TheCosmere'', such as the life-sensing ability of [[Literature/{{Warbreaker}} Awakeners]].
* All [[DifferentlyPoweredIndividual Others]] have this ability in ''Literature/NightWatchSeries'', no matter their level. However, a block is unlikely to work against a stronger Other. A scene in ''Day Watch'' has Anton and Alisher (who meet for the first time) test each other's mental defenses. Anton wins not by brute force but by trickery (he feints by reducing his defenses, as if Alisher's attack has managed to batter them down, then slips "under" Alisher's own block, when the latter becomes overconfident).
* The ''Franchise/StarCraft'' novel ''Liberty's Crusade'' has Sarah Kerrigan remark that Arcturus Mengsk is really hard for her to read telepathically. As she puts it, title character Mike Liberty is "all surface," and Mengsk is "all depth." When she really works at reading him late in the book, she is horrified at what she finds.
* In the ''Franchise/StarTrekExpandedUniverse'' novel ''Dark Mirror'', when Deanna is in psychic combat with her MirrorUniverse self, the narration says that due to a misunderstanding when she was a child developing her powers, she visualizes her psychic defenses as literal blocks. Children's blocks, with letters and pictures of animals on them. The battle ends with [[spoiler:Deanna calmly stepping straight through her counterpart's defenses while Mirror Deanna is battering against the blocks, because she's prepared to admit they're the same person]].

* ''ComicBook/{{Grifter}}'' initially had pretty strong psychic blocks, as result of Zealot teaching Cole how to remove (as well as recover when necessary) his PsychicPowers, making his mind almost impossible (according to Tao) to break into. Emphasis on almost, though, seeing as Tao did eventually find a way in. Later on, Lynch gives Cole all-new, even more powerful psychic blocks, to the point where Cole is now immune to Peter Grimm's powers (which can even cut through Holden Carver's defenses and are basically more powerful than even Tao's).

* Red Psyche-Locks in the ''VisualNovel/PhoenixWrightAceAttorney'' series appear whenever the truth-finding artifact magatama detects that someone is trying to hide something (the more locks, the more they want to hide it). The player character must present evidence and break the locks they can get to the truth. Black Psyche-Locks indicate a truth buried so deep that even that person doesn't realize they're hiding it.

* The Psyche-Locks in the ''VisualNovel/PhoenixWrightAceAttorney'' series. They keep secrets even from the lie detector Magantama and can only be broken through evidence. Notable that black ones are actually so deep that they are hidden even from the person who has them themselves.

* In ''VideoGame/CityOfHeroes'' we have The Seer Network of, main baddies, Arachnos; Which is made up of all the CharlesAtlasSuperpower psychics, telepathically linking to each other to reinforce their own loyalty to the Big Bad, and working so well that they patched other non-psychic baddies into it as a form of psychic security where they actually neutralize the synapses responsible for things like treason, resulting in extended mind control, outside mind reading or possession, just plain not able to operate in their brains; Consequently it also either detects double agents right away, or worse, overrides their ulterior goals turning them into triple agents.

* Adepts in ''VideoGame/GoldenSun'' are able to detect when other Adepts are trying to read their mind. This is usually less of an outright block than it is an interruption (Alex turning around and sassing the guilty party aloud), a PokeInTheThirdEye (Karst giving death threats through her thoughts), or a screen of PsychicStatic ("Ivan, stop reading my mind!"), but during a cutscene close to the end of the first game, Isaac & friends block Sheba from trying to learn about [[OrphansPlotTrinket Ivan's staff]].
* In ''VideoGame/HollowKnight'' five [[NonPlayerCharacter NPCs]] in total can know when their minds are read via the Dream Nail: The Seer[[note]]your mentor with the Dream Nail[[/note]], The White Queen[[note]][[GodEmperor Queen of the realm and a Pale Being]][[/note]], Bardoon[[note]]Implied to be because he is already hibernating[[/note]], The Midwife[[note]][[NightmareFuel who just screams]] for you to GetOut[[/note]] and the Snail Shaman. All of them except the Queen will chastise you to varying degrees for prying. The Queen is merely surprised.

* Nanomachines can be used to put up psychic barriers in ''VideoGame/MetalGearSolid'' and is in fact standard issue for pretty much anyone who possesses top-secret knowledge such as the two hostages who each have one of the titular Metal Gear REX's activation codes. The terrorists having somehow gotten the DARPA chief's code by reading his mind, despite the Armstech president pointing out this shouldn't have been possible thanks to those nanomachines is Snake's first clue that something strange is going on.
* Razputin from ''VideoGame/{{Psychonauts}}'' is first introduced as a badass when the local coach (a psychic himself) fails to probe his mind in the opening cutscene. Keep in mind, Coach Oleander is a psychic with years of training. Raz received little to no psychic training whatsoever.

* [[TelepathicSpacemen Takhisians]] in the ''Literature/WildCards'' series can learn to do this. The most "safe" defense includes conditioning yourself to commit telepathic suicide the instant someone breaks the wall, meaning it is impossible to read your hidden thoughts as all.

** Both ComicBook/{{Magneto}} and the Comicbook/{{Juggernaut|MarvelComics}} possess helmets that act as psychic defenses, usually against Professor X.

* In the ''WesternAnimation/JackieChanAdventures'' and ''WesternAnimation/TeenTitans'' crossover fanfiction ''Fanfic/AShadowOfTheTitans'', as WordOfGod says, Jade has this to some degree. Because she's a higher-level Shadowkhan, she has a natural resistance to mental powers and combined with a strong will and a third factor he refuses to identify (though it's implied to be [[spoiler: Tarakudo's presence in her mind]]), serves to make Brother Blood's MindControl almost entirely a NoSell for her.

* Literature/DifferentlyMorphous: Elizabeth once assigned an assistant to Dr. Diablerie with the express purpose of using his magically infused telepathy to probe Dr. Diablerie's mind for secrets; the end result was the assistant being sent to an insane asylum.

* Koishi from ''VideoGame/{{Touhou}}'' has a variation, in that her blocks are primarily against ''herself''. She's a Satori, a yokai with a third eye that allows them to read minds. Koishi however, grew tired of hearing people's bad thoughts about her and sealed her third eye away, which also prevented her from reading ''her own'' mind. This rendered Koishi completely thoughtless, and thus un-mind readable by virtue of not having anything to read. As such, [[TheDitz she's "kinda dim".]]

* In ''Franchise/StarWarsLegends'', Mara Jade has this power. Apparently the Emperor taught this to her as he wanted agents that his [[TheDragon Dragon]] Darth Vader can't read, due to not trusting him fully. Of course that still didn't save him in the end.

-->-- ''WesternAnimation/TheVentureBrothers'', "The Doctor Is Sin"

** Presumably why Tosh can't read Jack's mind while wearing the pendant in the episode "Greeks Bearing Gifts". He says he could feel her "scrabbling about in there" but for some reason, she couldn't hear anything unless Jack deliberately communicated a thought. This is likely a result of his training as a Temporal Agent. Given how many psychic beings there are in the universe, an operative needs to be able to keep others out of his mind. Even Torchwood 1 provides some resistance training to weak psychic influence.

* In ''WesternAnimation/TheVentureBrothers'', Dr. Killinger is somehow immune to telepathy. When Dr. Orpheus attempted to read his mind, Killinger calmly stood in place until Orpheus overexerted himself and passed out from a PsychicNosebleed.

** In recent issues, it's revealed that ComicBook/{{Cyclops}}, despite not being a telepath, has a small box inside his mind that Emma can't move or open, which contains secrets to do with the safety of the X-Men. Jean taught him how to do it.
** The very nature of ComicBook/{{Gambit}}'s bio-electric powers render him very difficult to mind-probe -- ComicBook/ProfessorX compared reading his thoughts to trying to grasp a snake coated in oil. Not ''impossible'', but certainly mentally taxing and liable to hurt the Cajun just as much. He also has purposely-placed psi-blocks. He lived among four of the world's most powerful telepaths for years while hiding the fact that he used to work for Mr. Sinister and helped create the Marauders.
** Storm is another X-Man whose powers make her naturally difficult for telepaths to read, to the point where the Professor compared reading Storm to attempting to grab a charged lightning rod during a thunderstorm.

** During the ''Operation: Zero Tolerance'' story the government operative Bastion displayed this ability, being completely immune to all the telepathic probes of both Professor X and Cable. Eventually, TheReveal was made that Bastion was not actually human at all, but rather a RidiculouslyHumanRobot.

** Doug, whose mutant ability is to interpret and translate any language, boasts that he's encrypted his thoughts into a language of his own invention. Telepaths can read his mind as easily as anyone else's, but actually understanding it would take an unwieldy amount of time and resources.

* ''Literature/{{City of Bones|1995}}'' by Creator/MarthaWells:

* In ''Literature/TheDamnedTrilogy'' by Creator/AlanDeanFoster not only humans are immune to psychic powers of Amplitur, but applying telepathy to humans turns out to be very painful and near-fatal. [[spoiler:Later we find that Lepar are immune too, but they don't hurt Amplitur.]]

** In most of the Dresdenverse, since the White Council tightly regulates mind magics, Harry has very poor, basic defenses which [[spoiler:the Corpsetaker]] can easily breach. However, in the novel ''Literature/GhostStory,'' due to training from Harry's faerie godmother, [[spoiler:Molly]] mounts a more effective defense. Harry only gets inside because he knows the person well and knows where to look during that person's BattleInTheCenterOfTheMind with [[spoiler:the Corpsetaker]].
* Creator/JamesHSchmitz's ''Literature/FederationOfTheHub'' stories: Mind shield devices were commercially available, and creatures known as Old Galactics could provide them to their symbionts (such as humans).

* In Creator/EEDocSmith's ''Literature/{{Lensman}}'' series, both mechanical and mentally-generated thought screens are very common. Mechanical thought screens will stop telepathic probes by minds of second stage and lower, but will barely even slow down the probes of third-stage minds. Mechanical screens are also vulnerable to being physically switched off or sabotaged, either by the hostile telepath or by an unprotected creature that the hostile telepath mentally controls. Mentally-generated thought screens are immune to being physically switched off but can be penetrated by more powerful or more advanced minds.

* The ''VideoGame/StarCraft'' {{novelization}} ''Liberty's Crusade'' has Sarah Kerrigan remark that Arcturus Mengsk is really hard for her to read telepathically. As she puts it, title character Mike Liberty is "all surface," and Mengsk is "all depth." When she really works at reading him late in the book, she is horrified at what she finds.
* In the ''Series/StarTrekTheNextGeneration'' novel ''Dark Mirror'', when Deanna is in psychic combat with her MirrorUniverse self, the narration says that due to a misunderstanding when she was a child developing her powers, she visualises her psychic defences as literal blocks. Children's blocks, with letters and pictures of animals on them. The battle ends with [[spoiler: Deanna calmly stepping straight through her counterpart's defences while Mirror Deanna is battering against the blocks, because she's prepared to admit they're the same person.]]
* In ''Franchise/StarWarsLegends'', Mara Jade has this power. Apparently the Emperor taught this to her as he wanted agents that his {{Dragon}} Darth Vader can't read, due to not trusting him fully. Of course that still didn't save him in the end.
* In the ''Literature/{{Twilight}}'' stories, Bella Swan has a completely effective, passive mind shield that prevents anyone from reading her thoughts or invading her mind. In the last book, [[spoiler:when she becomes a vampire, she learns how to extend her shield to protect others against all forms of mental attack, and how to lower her shield to let Edward in.]]

* The Author of the Journals in ''WesternAnimation/GravityFalls'' is shown to have installed a metal plate into his skull to prevent mind manipulations. Later, he developed a machine that can encrypt brainwaves to do this without such surgery. [[spoiler:Specifically, from a certain [[EldritchAbomination Bill Cipher.]]]] This ends up backfiring when he ''needs'' to let himself be possessed, [[spoiler:necessitating his brother [[TwinSwitch impersonating him]] to do it in his place]].

** Thannagarians such as Hawkgirl have psychic block defences that keep telepaths such as J'onn from reading their minds. [[spoiler:J'onn manages to overpower one in the second season finale, but the effort physically wounds him and [[MindRape more or less reduces the Thannagarian to a vegetative state.]]]] In later episodes said Thannagarian does come back having recovered at least somewhat, but is now permanently affixed to a life-supporting combat mech and has severe brain damage to the point he's constantly confused and can barely comprehend what's going on around him.

* ''WesternAnimation/YoungJustice'':

** In-universe this trope isn't used, instead opting PsychicStatic. [[spoiler:Until the Anti-life equation is shown to hide its subjects from telepathic detection.]]

* In ''LightNovel/ACertainMagicalIndex'', an unexpected side effect of Misaka's electricity powers is immunity to psychics, as her natural electromagnetic fields interfere with their mental signals. Touma is also mostly immune to telepathy due to [[AntiMagic Imagine Breaker]], though one exceptionally powerful psychic was barely able to get a thought into his head (which would have instantly been erased if he had so much as touched his head with his hand).

* ''LightNovel/ThatTimeIGotReincarnatedAsASlime'': After Rimuru's [[BenevolentAI Great Sage]] evolves into Wisdom King Raphael, Raphael gains enough strength and awareness to not only recognize when someone is trying to mind-probe Rimuru but can also block them out at her discretion.

** Claudia can shield her thoughts from Louis when he telepathically inquires about the identity of Charlie, the young man she has a crush on.

** Louis is also unable to access Claudia's thoughts during her 7-year-long absence, so he doesn't know where she has gone or what she's doing.

** During ''ComicBook/Inferno2021'' Doug, whose mutant ability is to interpret and translate any language, boasts that he's encrypted his thoughts into a language of his own invention. Telepaths can read his mind as easily as anyone else's, but actually understanding it would take an unwieldy amount of time and resources.

** Louis is also unable to access Claudia's thoughts during her 7-year-long absence.

* ''Series/InterviewWithTheVampire2022'': Claudia can shield her thoughts from Louis when he telepathically inquires about the identity of Charlie, the young man she has a crush on.
-->'''Louis''': Who's Charlie?\\

* In ''VideoGame/HollowKnight'' five [[NonPlayerCharacter NPCs]] in total can know when their minds are read via the Dream Nail: The Seer [[note]] your mentor with the Dream Nail [[/note]], The White Queen [[note]] Queen of the realm [[/note]], Bardoon [[note]] Implied to be because he is already hibernating [[/note]] The Midwife [[note]] [[NightmareFuel who just screams]] for you to GetOut [[/note]] and the Snail Shaman. All of them except the Queen will chastise you to varying degrees for prying. The Queen is merely surprised.

* In '''Manga/TheDisastrousLifeOfSaikiK'', three characters are immune to Saiki's telepathy: Nendo, due to his low intelligence, Touma, due to having too many thoughts in his head to parse, and Kusuke, who wears a device specifically made to block out mind reading.