Gaz: You're in my light.
The hero decides that the only way to defeat the enemy is to understand how the enemy thinks in the most intimate and experiential way possible, to get inside the enemy's mind either literally or figuratively. The hero may accomplish this with the aid of drugs, Psychic Powers, or some other strategy. May result in a Not So Different realization, or even a personal epiphany (or Epiphany Therapy if done badly). There is also the danger of Becoming the Mask when attempting this with a practical approach!
Compare Consulting a Convicted Killer, where the law-abiding protagonists ask a dangerous criminal with a background much similar to the person on the loose to try to suss out how the criminal mind works. Contrast That's What I Would Do.
- In Monster Inspector Lunge uses this method all the time, narrating it as he goes: "I am X... What do I do now?" For most of the series, X is Tenma or Johan (whom he assumes is a split personality of Tenma).
Lunge: "I am Tenma. I am Japanese... domo."
- In Neon Genesis Evangelion, Shinji and Asuka get their asses kicked by Israfel who is "one mind in two bodies". To defeat him, the two do a synchronisation training where they do absolutely everything in complete unison. At the end, they are even shown sleeping in the exact same pose. Due to the power of Soundtrack Dissonance (they helped their synch by timing their attacks to music), it worked.
- Soul Eater: this happens during Maka and Crona's second battle. In order to understand Crona's soul, which is hidden by their insanity, Maka goes insane herself.
- Played for laughs at the climax of the Alabasta arc in One Piece. While most of the main characters are hunting down a massive bomb set up by Crocodile, Usopp's big idea is to start doing a comical impression of Crocodile in an attempt to figure out how he thinks. This earns him a Dope Slap.
- In V for Vendetta, Inspector Eric Finch, in order to understand V's motives, visits the concentration camp where V was driven insane (and from which he escaped), and takes a massive amount of LSD. The resulting "imprisonment and escape"-themed acid trip not only helps Finch comprehend V's mind and thereby discover his hideout; it also leads Finch to confront his moral ambivalence, guilt and "trapped" feeling regarding his job, and ultimately to the V-like realization that he's his own jailor and can free himself.
- A somewhat inadvertent example occurs in Batman: The Man Who Laughs. Bruce Wayne, targeted by the Joker and under police guard, takes a non-lethal dose of the Joker's venom so that Alfred can spirit him away in an ambulance and allow him to change into costume. However, before the antidote Alfred gives him takes effect, Wayne has a brief psychotic episode in which he blames all of Gotham for his parents' death and swears revenge. Upon regaining his wits, Batman suddenly understands the Joker's paranoid thought process and deduces that the villain means to kill the entire city.
- In JLA# 11, in order to navigate a holographic maze controlled by the mind of The Joker, the Martian Manhunter reconfigures his brain so he can think like him.
- In Bookhunter, when Agent Bay discovers that the thief he's hunting is a dark-haired woman, he announces that he's going to get himself fitted for a black wig. He explains, "To catch a thief, you must think like a thief. You must live, eat, and dress like a thief." This is never really followed up on.
- When The Kingpin hires Bullseye to kill Frank Castle in The Punisher MAX, Bullseye first fails to kill Frank when he shows up and tries to snipe the Kingpin. With his first attempt a failure, Bullseye embarks on a quest to get inside Frank Castle's head by sleeping in his old hideouts, wearing his clothes, eating his food, and finally, to try and recreate what created the Punisher in the first place - by kidnapping families, then having them murdered in the park while pretending he's the father. He repeats this three times, but still doesnt succeed, until he spends a week isolated in a room while staring at old family photos of Frank and his family, and finally realizes something that no one else has: Frank's last words to Lisa before she and the kids were killed - "I'm leaving".
- Literally in George's case in The Keys Stand Alone: The Soft World. When he becomes another creature, he thinks like that creature, sometimes to the point where he almost loses his own personality until something (usually the thought of his wife) snaps him back. So when he becomes a Leader Tayhil so he can boss other Tayhil around, he learns a lot about Tayhil in general. Later, he ponders shapeshifting as an aid to interspecies understanding.
- An early example in 1920 silent movie The Cabinet of Dr. Caligari, where the asylum director has a Villainous Breakdown and desperately attempts to become the mythical character Caligari in order to continue his work. "I must know everything. I must penetrate the heart of his secret! I must become Caligari!"
- Though not literally becoming a different person, Batman Begins had the brilliant line "To conquer Fear; You must become Fear."
- In Face/Off, FBI agent Sean Archer has plastic surgery to resemble criminal mastermind Castor Troy, who is conveniently in a coma and in custody, adopts his mannerisms, and gets himself jailed to find out the location of a bomb from Troy's brother. However, Archer soon finds himself Hoist by His Own Petard when Troy awakens, forces the doctors to give him Archer's face, kills everyone who knows about the switch, and takes his place at home and work.
- In Dark City, Mr. Hand volunteers to inject himself with the memories John should have received, so he can better understand their quarry.
- Training Day: "It takes a wolf to catch a wolf."
- Played for Laughs in Caddyshack. Carl Spackler tries to get into the mind of a gopher in order to kill it.
- This is Will Graham's whole modus operandi — and curse. In fact, he had to spend some time in a mental ward just because that's what having to think as foully as Hannibal Lecter did to him.
- The whole reason children, and specifically Ender, are trained the way they are in Ender's Game. Only someone who completely sympathises with and understands the buggers can predict their tactics and defeat them, but anyone who could understand them that well couldn't bring themselves to wipe them out. So you train children up and don't let them know they're already commanding real armies in real war; an adult would see through this. (Also, they have nimble video-game-playing fingers.)
- Older Than Feudalism: Sun Tzu said
If you know both yourself and your enemy, you can come out of numerous battles without danger.If you only know yourself, but not your opponent, you may win or may lose.If you know neither yourself nor your enemy, you will always endanger yourself.
- Interestingly, in something of a subversion, he was being very literal. That passage is about the importance of Military Intelligence.
- In Terry Pratchett's Discworld novel Making Money, the antagonist Cosmo Lavish is obsessed with becoming Lord Vetinari. Not with taking over Lord Vetinari's power and position, but with actually becoming the man. It's kind of sad, really.
- What's more tragic is the fact that there's a ward of people with the same delusion. Even in his insanity, Cosmo couldn't be original. Although he did win the eyebrow-raising competition later that week so at least he's good at what he does.
- On a related note, any Anthropomorphic Personification that spends much time observing humans invariably comes to take on human characteristics. Discworld's Death is the primary example. This is also said to be because all Anthropomorphic Personifications are a product of the collective minds of sentient races. It may have been described that way in Thief of Time
- G. K. Chesterton's priest-detective character Father Brown claims that this personal insight into the sinful, criminal mind is the main reason for his success, built on the confessions he hears from criminals while attending to his clerical duties.
- In Dan Abnett's Ghostmaker, Inquisitor Lilith had, in her Back Story, lost her mother to eldar. She threw herself into destroying them, and then into understanding them. She ends up sealing a Way for them and being carried back to their world.
- The Stainless Steel Rat uses drugs and hypnosis to take on Angelina's sociopathic personality, in order to work out what her next move might be after losing track of her on an alien planet. Sociopathic!Jim realises that Evil Feels Good and decides to keep taking the drug, but fortunately his normal self took the precaution of setting up a sleep-gas boobytrap inside his gun case, so he gets knocked out until the drug wears off. The plan works though, as Jim realises that Angelina's self-centred narcissism will make her Take Over the World (sure enough, she's working behind the scenes to launch a revolution).
- Doctor Who, Curse of Fenric: During WWII, British Commander Millington has a room in his HQ that looks just like Hitler's office, so he can think like he thinks. (Millington is pretty unstable — though not a Nazi.)
- The Pretender, a series where the protagonist's thing is being able to think like other people, did an inversion in the episode "Once in a Blue Moon": Jarod has to catch a serial killer, and tries to without Becoming Him, because he's afraid that once he starts thinking like a homicidal psychopath he won't be able to stop.
- The X-Files: There was an episode where there's a gruesome series of killings. Turns out Mulder's old mentor in criminal profiling is doing it — after thinking like a certain killer he was trying to catch for twelve years, he really did become him.
- The first-season explanation behind Frank Black's abilities in Millennium. The second and third seasons turned it into something more mystical, against creator Chris Carter's original plan.
- This is more or less the premise of Criminal Minds. "I'm the unsub..."
- Star Trek: Deep Space Nine: The episode "Field of Fire" centers around Ezri Dax tracking down a serial killer on the station in this way. Made more literal by the fact that one of her previous hosts was a murderer.
- Inverted in the episode "Facets," where to get to know Dax's previous hosts better, Jadzia must temporarily take them out of her mind and into friend's bodies.
- In the Law & Order: Criminal Intent episode "Vacancy", Goren and Eames come to suspect that a method actor who was working on a role as a serial killer may have got so method that he ended up killing someone himself. They're right, although his motive is a bit more complicated than that.
- Ultra Series
- Taken to dangerous extremes for Will Graham, the main character in Hannibal (adapted from Red Dragon; see above), who uses "pure empathy" to think/feel like the serial killers the team has to find in order to reconstruct their motives and bring about their downfalls.
- There was an episode of the radio version of The Mighty Boosh where there was a villain stealing animals from the zoo. Howard wants to do a psychological profile, get inside the fiend's head and work out when he'll next strike... and Bob Fossil and Vince suggest flying around in a helicopter firing flares everywhere.
- In Resident Evil: Survivor, the first light-gun entry into the series, the protagonist is investigating an Umbrella lab island by impersonating the evil director. This does have a risky side: on losing his memory during the investigation, all of the evidence available made him believe he was the director. Fortunately, he decided that even if he WAS the director, he didn't need to be a dick any longer.
- In The Suffering, the toxic ghost of Executioner Hermes Haight reveals that during the months leading up to his death, he became obsessed with knowing what his victims felt before they died in the gas chamber: merely watching them yielded nothing, and listening to their phone conversations just made him feel like they knew something he didn't; even having sex with their corpses didn't satisfy his curiosity, so he concluded his obsession by "tasting the gas".
- The entire point of both X-COM: UFO Defense / UFO: Enemy Unknown, the entire strategy is to "know" and then "become" the enemy through research and emulating the enemy's tactics. This is much more pronounced in the recent remake XCOM: Enemy Unknown(2012).
- Robin and his Red-X alter ego in Teen Titans.
- In the Darkwing Duck episode "Disguise the Limit", Darkwing tries this to find his Evil Twin Negaduck's hideout. Problem is, he's also suffering from that week's Applied Phlebotinum accident. He actually becomes Negaduck. You can find Negs under the Omnicidal Maniac pages; Gosalyn and Launchpad easily find him by following the trail of destruction. Then again, he did find Negaduck. And then accused him of being a fake.
- The Simpsons
Homer: To find Flanders, I just have to think like Flanders! (thinking) I'm a big four-eyed lame-o, and I wear the same stupid sweater every day and - (aloud) The Springfield River!
- In one episode, Ned has taken Bart, Lisa and Maggie to the river to baptize them. Homer and Marge are searching for them.
Marge: Why do you always hire the cheapest guy?!Homer: I go by how funny his sign is.
- In another episode, they hire an exterminator to kill a termite infestation. The Sarcastic Middle-Aged Man says that to find the bugs he'll have to "think like a bug, act like a bug, become a bug!" He then starts gnawing on the table.
- Played for Laughs in Steven Universe. In the episode "The Kindergarten Kid", Peridot and Steven spend the entire episode trying to catch a corrupted gem. When none of Peridot's traps work, Steven suggests she "tries seeing things from [the monster's] perspective". Peridot's idea of doing this is imitating the monster. By lightly jumping up and down and sticking her tongue in the air. It works, until Peridot decides to kick her, pissing her off.
- Parodied in Family Guy when the Griffins house is infested with termites. Peter suggests that they adapt the termites customs, wear their clothing, and breed with their women, and "eventually, our differences will be forgotten".
Lois: JUST CALL THE DAMN EXTERMINATOR!!!
- Another episode has Stewie afraid of the Tooth Fairy, and decides to capture him. He states that, "to find a fairy, he has to think like a fairy". Brian then gives an Aside Glance, and a narrator gives the viewer the options of choosing between two incredibly obvious gay jokes, and having Brian do a Mexican hat dance.
- Squidbillies: Early references this by name while explaining to Granny that the only way to understand his convoluted, drunken instructions is to be an angry ranting drunk.
Early: Dammit, it ain't always what I say! Sometimes it's what I mean! Hell, you gotta think my thoughts! "To understand him, you must become him."Granny: Well, I'm not a mind reader.Early: And you about to not be a mind haver in yo' skull neither! Now knock 'em kitty cats down to fifteen a load and see if we get a nibble.
- This is played for laughs in American Dad!, when Roger tasks himself with finding Haley and Jeff to steal the money they conned from Haley's parents to elope with. When Klaus questions how Roger will find them, Roger replies, "to find a stoned loser, I must become a stoned loser". After taking a large hit off a water bong, he begins skateboarding off down the street. Suddenly the pot kicks in and he skates through a psychedelic acid sequence to MGM's "Electric Feels" before face-planting on a beach in Thailand, right in front of Haley and Jeff.
- Supposedly, General Montgomery kept a picture of Rommel on his desk and tried to think like him, and this brought about his victory. There's a funny line in The Ipcress File where after the First-Person Smartass narrator is told this story (in reference to thinking like the enemy), he thinks to himself that the extra tanks probably helped.
- Certainly, Montgomery didn't fight much like Rommel. Monty was a master of set piece battles where you lay out your troops, plan out everything, and launch a complicated, finely tuned attack. Rommel could do that, but he was at his best in a freewheeling mobile battle.
- It wasn't so much a case of trying to become like Rommel as it was a case of trying to predict his moves. Monty's decision not to pursue Rommel's forces came about because of how well he had studied the Desert Fox. He knew Rommel's strength was in running battles, and he was not about to play to that strength.
- Method Acting, a typing of acting skill in which an actor tries to become and think like the character in order to understand the character.
- In the 1920's World Chess Champion Jose Raul Capablanca was unbeatable. In one particular 8 year span, he never suffered a single loss. His style defined coolness and precision at that time. He was challenged by Alexander Alekhin, a man who never won against him. Alekhin's style was fiery and risk loving, or in other words, he was easy prey for Capablanca. In 1926, Capablanca's cool and precise style sat down to meet Alekhin's—cool and precise style! In the months preceding the match, Alekhin completely analyzed and dissected Capablanca's style (such preparation was unheard of during that time). He determined that the only way to win was to out-Capablanca Capablanca. He tightly controlled his aggressive and risky tendencies. He even agreed to easy draws because that was how Capablanca would play that position. It worked. Alekhin became the next World Chess Champion.
- The above Batman Begins example was deconstructed by stand-up comedian Reginald D. Hunter, pointing out that it was just a way to do what you want. Point in hand, he uses it as an excuse if someone takes offence to his Josef Fritzl routine.
- "To conquer Fritzl; You must BECOME FRITZL!"