You Won't Feel a Thing

Stock Phrase uttered by a character who is about to do something potentially nasty to someone. They tell their victim that what they are about to do won't hurt at all. This often turns out to be a blatant lie.

This is often done by doctors or friends of the victim who genuinely mean well, and are just trying to help them. However, it can also be used as a sarcastic Pre-Mortem/Pre-Ass-Kicking One-Liner by someone who is about to inflict a lot of deliberate pain on their victim.

Another common variant is "This may hurt a little." This variation tends to be popular with Mad Scientists. A particularly psychopathic or dickish character may instead say, "I won't feel a thing."

Definitely Truth in Television, as anyone knows who has been to the dentist.

Often used to set up False Reassurance.

Anime and Manga
"Ryoko: I won't hurt you... Too much!"
 * Tenchi Muyo! Ryo-Ohki:


 * D.Gray-man (anime) subverts this with Komui telling Allen, "When I get done with you, you'll be good as new. Though I must warn you, this will be traumatic."
 * Magical Girl Lyrical Nanoha StrikerS has Nanoha saying "This is going to hurt a bit" to her daughter during the finale before.

Film
"Mr. Copperbottom: [chuckles] We did want a boy, right? [He takes the piece and a hammer] This won't hurt a bit, son. [He hammers the piece in, Rodney cries]"
 * The Remake of The Day the Earth Stood Still: Klaatu says "the pain will only be momentary."
 * The 2010 A Nightmare on Elm Street reboot: "This won't hurt one... little... bit..."
 * Robots. After Rodney is assembled, an extra piece is found.

"Carrigan Crittenden: [stalking after Dibs, carrying a huge battle axe] Damn it, Dibs! This won't hurt a bit!"
 * Casper

"Doctor Allenby: This won't hurt a bit. [Sticks Chance with a needle] Chance the Gardener: It did hurt."
 * Being There

"Dr. Cockroach: Now, you might feel a slight pinch in the brain. Mwahaha... Sorry."
 * Chill Factor: An assassin tells one of the protagonists, as she is about to execute him: "Don't worry, I'm a professional, this won't hurt a bit."
 * Given an Ironic Echo a short while later after he ends up gaining the upper hand: "I'm an amateur, this is going to hurt like hell."
 * Variation in Monsters vs. Aliens:


 * One of the tag lines for Michael Moore's Sicko (a documentary about health care in the US and around the world) is "this may hurt a little". Promotional materials also use "get well soon!"
 * Bedazzled - the Devil offers Stanley seven wishes for his soul. Stanley has misgivings and asks "But if you took it out, wouldn't it hurt?" The Devil replies "It's a perfectly painless operation, and afterwards you won't feel a thing!"

Literature

 * In Ender's Game, Ender is told "it won't hurt a bit" to have his monitor taken out, but Ender knows that adults say that when it is going to hurt.
 * Similarly, in Coraline, the Other Parents tell Coraline this when they try to convince her to let them sew the buttons on her eyes. Coraline doesn't believe them for an instant.
 * Discworld has the troll retrophrenologist truthfully informing his client "This won't hurt a bit" as he readies the mallet. (Phrenology being the pseudo-science based on determining a person's mental state and personality by measuring the skull and variations thereof. Retrophrenology "works" by introducing new variations to the skull to modify said mental state and personality...)
 * There's a sequence in Unwind where a Walking Transplant on the operating table is notified that he may feel something in his feet, but not to worry. Then, a little later, he's told that he may feel something in his legs. This proceeds far longer than you might expect.
 * In The Mysterious Benedict Society, one of the Recruiters tells the children "If you children stay nice and still, I promise this won't hurt a bit." The other Recruiter that is with him suggests "Oh, come on, let's tell the truth for once. Just for kicks." The first Recruiter then admits "All right, the truth is that this will hurt. A lot. But if you hold still, I promise it won't hurt for long."

Live Action TV
"Dr. Gregory House: You won't feel a thing... Except this excruciating pain."
 * House episode "The Itch".

"Doctor: Don't worry, you won't feel a thing. Dan Scott: So tell me Doc, how many heart transplants have you done? Doctor: [Takes electric saw from nurse and turns it on]"
 * One Tree Hill episode "I Just Died in Your Arms Tonight"

"Captain Archer: Dr. Phlox is going to have to perform an operation. Sim Trip at 8: Will it hurt? Dr. Phlox: Not at all. You won't feel a thing. Sim Trip at 8: Doctors always say that."
 * Luckily for Dan, it turns out to be a nightmare.
 * Star Trek: Enterprise episode "Similitude"

"Beatrice Mailer: This won't hurt a bit. [Holding her father's bleeding hand, she squeezes lemon juice onto an open knife cut as he silently flinches] Remember the first time you told me that?"
 * Law and Order: Criminal Intent episode "Death Roe"

"Dr. Forrester: Now this leech [snip] when applied to the neck or head area, will suck any desire to smoke out of Frank. Frank: [loudly protests] Dr. Forrester: But this won't hurt a bit."
 * Mystery Science Theater 3000 episode "Attack of the Giant Leeches"

"Elaine: It's not going to hurt a lot, is it? Doctor: Yes, very much."
 * Seinfeld, "The Glasses", has a subversion:

"Chris: Don't fret, boss. I've got you covered. Quick and clean, I promise.""
 * A variant appears on The Wire's fourth-season premiere, where enforcer Chris Partlow prepares to execute a dealer in a vacant house.

"Chekov: "Give us some more blood, Chekov. The needle won't hurt, Chekov.""
 * The Star Trek: The Original Series episode "The Deadly Years" has three examples while the Enterprise medical staff is trying to figure out why Chekov was not affected by the Rapid Aging effect that struck the rest of the landing party.
 * Subverted when Dr. McCoy tells Nurse Chapel to prepare Ensign Chekov for another physical. She tells Chekov "This won't hurt...much."
 * Later on Chekov complains about the multiple medical exams by repeating what he's been told during them.

"McCoy: Now this isn't going to hurt a bit. Chekov: That's what you said the last time. McCoy: Did it hurt? Chekov: Yes!"
 * Dr. McCoy continues to test Chekov.

"John: Hey look I know you guys lie and all, but th-this is not gonna hurt too bad is it? Doctor: (cheerfully) Not a bit. (The doctor turns on his Mind Probe, causing John's head to light up as he shrieks in agony) D'Argo: (later) If you'd held your scream off one more microt I would have won the pool."
 * Averted in the 9th season of the Israeli sitcom LifeAin’tAll opening episode, in which Orli has become a dental hygienist. Although she gets extremely good results, to the point her patients’ teeth shine a blinding light when they open their mouths, she is seen explaining to one patient she has absolutely no aversion towards her patients’ pain.
 * Farscape "Coup by Clam". The crew of Moya are being examined by a doctor for Space Madness.

"Spike: Tell you what; as a personal favor, from me to you, I'll make it quick. It won't hurt a bit. Buffy: No, Spike. It's gonna hurt a lot."
 * Buffy the Vampire Slayer. Spike to Buffy in their very first fight in "School Hard". Spike boasts that the last Slayer he killed begged for her life, but...

"“Now, be a good girl and hold still. This will only hurt a lot.”"
 * A line cut from "Innocence" had Angelus saying, "It won't hurt a bit...after the first hour."
 * Angel. A villain is about to forcibly remove Cordelia's eyes.

Music

 * "Tell me, Jimmy, I won't feel a thing..."
 * The Black Parade: "It was a lie when they smiled and said you won't feel a thing" (Disenchanted)

Toys
"Brutaka: But if you want people to believe you caught this dangerous criminal, you will need to look like you've been in a fight. A light tap to your head would do the trick, perhaps. My colleague, Vezon, can handle it -- you won't feel a thing. Vezon: Ever Again."
 * From Bionicle:

Web Comics

 * Friendly Hostility: Charlotte, a Mad Scientist in training, uses her father's employee Derringer as a guinea pig for a machine labelled "Schroedinger's Derringer". "Now in a moment you may or may not feel a tingly death ..."

Western Animation
"Mr. Freeze: You may feel some momentary discomfort."
 * The Batman Beyond episode "Meltdown":

"Dr. Nick Riviera: Don't worry. You won't feel a thing [exhibits a swirling mechanical device]...till I jam this down your throat!"
 * The Simpsons "The Springfield Files"

"Roger: A mind-switching machine. Is this gonna hurt? Kowalski: Just a slight pinch, followed by the brief sensation of a thousand suns exploding in your skull."
 * The Penguins of Madagascar:, "Roger Dodger":

"Dr. McCoy: [about to give an injection] This won't hurt a bit, Spock. Mr. Spock: An unnecessary assurance, doctor, in addition to being untrue. Dr. McCoy: That's the last time I waste my bedside manner on a Vulcan."
 * Star Trek: The Animated Series episode "The Pirates of Orion"

"Dennis: Don't worry, this'll only hurt a lot!"
 * Subversion in The SpongeBob SquarePants Movie: