The villain has cornered a beautiful maiden! Trembling at the very thought of his touch, she tearfully lifts her skirt, things look bad — but what's this? She's pulled a knife from her garter! Before he can react, she stabs him, stopping the Attempted Rape and possibly putting an end to his evil ways once and for all.
The Chastity Dagger is the favored weapon of delicate young ladies in fantasy and historical works. It is almost always used as a means of self-defense when in danger of being raped, robbed or kidnapped, but a Femme Fatale may also use it in conjunction with her feminine charm to assassinate a male character while he is distracted. A more modern variation is the Little Useless Gun.
An inversion almost as common as the trope itself is when the knife is like a Cyanide Pill for suicide rather than self-defensive — averting Fate Worse than Death and invoking Better to Die than Be Killed.
For a fantastic, Body Horror variation, see Vagina Dentata. Though it should be noted that that trope is almost never used in applying this trope, unless it's part of a Karmic Death or Mugging the Monster situation meant to introduce the real Monster of the Week.
- While not a dagger, Casca from Berserk uses a chastity stick in order to plunge it into the eye of a would-be rapist during the battle with Adon's soldiers.
- Prince Vald of Crimson Spell has a magical variation, cast by his Violently Protective Boyfriend, Halvir. If anybody besides Havi attempts to penetrate Vald, it triggers a powerful energy blast and alerts Havi to the fact that Valds in trouble.
- In the penultimate episode of the OVA Iriya no Sora, UFO no Natsu, Iriy Kana uses a hidden dagger to fend of a homeless man trying to have his way with her.
- In Robin Hood no Daiboken, Marian's only weapon before she takes a level in badass is a small knife. She uses it to nearly take her own life when faced with being mauled by dogs, and later tries to stab Bishop Hartford when he coerces her into marrying him.
- Fuu of Samurai Champloo always carries around a tanto that she calls her "trusty maiden's dagger." It's clearly meant to serve this purpose, but she's laughably ineffective at using it.
- Prince Valiant: Princess Aleta has one of these, and she uses it to great effect on numerous occasions, whether to free herself from ropes or to stab an unsuspecting villain.
- In Blood Ties, Noa sleeps with a knife because she had previously been gang-raped, beaten, and left for dead.
- In Hope for the Heartless, the Horned King decides to teach Avalina self-defense and has a dagger crafted for her, telling her to keep it hidden if possible and use it seriously if out of options.
- In Maria Campbell of the Astral Clocktower, Maria begins carrying one for fear Katarina should "press her suit with a sword in hand".
- 10,000 BC: The lead warlord buys Evolet as his concubine and tries to have a private moment with her. As he prepares to have his way with her, she pulls out a knife to kill him. However, they are then interrupted by the Atlantean's servants who are none too pleased to see that the warlord tried to keep one of their master's slaves for himself.
- Circus of Horrors: Elsa is first introduced as a prostitute. She conceals a stiletto down her cleavage that she uses to stab her client and steal his wallet.
- Pan's Labyrinth: Mercedes carries such a knife. It's the same knife she uses to chop food in the kitchen, and she's shown multiple times folding the knife back into her dress after she's done chopping vegetables. Her knife is not only used against her attacker, as is traditional, but also to cut through ropes binding communist prisoners' wrists.
- Played Straight, on the other hand, by Maid Marion (note the different spelling) in Robin Hood (2010).
- A double subversion in Robin Hood: Prince of Thieves; The Sheriff of Nottingham gives Maid Marian a dagger for protection. However, she can look after herself and donates it to Robin's cause. Then, in the final battle when the Sheriff's in full on I Have You Now, My Pretty mode, Robin turns up and (after being disarmed) ultimately uses the dagger as a weapon of last resort to save her.
- Romancing the Stone's Fake-Out Opening ends this way. And the ex-Shrinking Violet heroine resorts to a Chastity Switchblade before it's all over.
- In Sherlock Holmes (2009), thugs attempt to rob Irene Adler at knifepoint. Irene takes out a concealed knife and robs the robbers.
- This was a favorite tactic of Milady DeWinter in The Three Musketeers (1993).
- In Troy, Briseis stabs Agamemmnon this way during the sack of Troy.
- Inverted in the original version of Aladdin: Having had the genie kidnap the princess to his palace, he puts a big scimitar on the bed between them so she can use it if he gets too familiar.
- In the Belgariad and sequels, Nadrak women have about four of them handy at all times. At least one of them is always on display to remind men of the consequences of taking liberties, with "lesser offenses" usually just earning a nasty scar.
- A Brother's Price: Jerin carries not only a dagger but also a small gun hidden under his clothes. It is this trope, as men are not usually armed in his culture. His family is a bit unusual in that respect. It later turns out that he also carries a couple of lockpicks. It shows that their grandmothers were soldier-spies in the war—everyone in the family is armed. (Yes, even the toddlers.) This causes great surprise when the family turns in their weapons before a visit at the royal palace, and Jerin is ordered by his eldest sister to be honest about his hidden weapons, as they don't want trouble. Later on, the kidnappers are a bit more genre-savvy than is good for Jerin, and take his chastity dagger and gun away before he can use them. That is, until he applies some other skills men in his culture generally don't have, retrieving gun and lockpicks in the process.
- Conan the Buccaneer has the inversion—all the virgins of Zingara carry small knives to kill themselves (they value chastity a bit too highly).
- Discussed a couple of times in the Gor series; in Beasts of Gor Tarl strips a free woman and makes her comb her hair, where she has a poisoned needle hidden. At least one other time Tarl talks to a free woman about it too, saying she'd better not have a hidden dagger or it won't go well for her with her captors.
- The Elenium and its sequels feature Mirtai, who always has knives on her person and more than once used them to protect her innocence after having been sold to a brothel. She even keeps knives strapped to her inner thighs to ensure that she can fight off any attacker. In fact, she once sharpened the end of a spoon when a little girl. Put it to good use and still has it.
- Esmeralda has one in The Hunchback of Notre Dame, though she doesn't kill anyone with it.
- Aliena from The Pillars of the Earth carries one strapped to her leg ever since she was raped early in the book.
- In The Pyrates, Anne Bonney prepares for the invasion of her island by tucking a stiletto into her garter; in case some token resistance is expected before her ravishment.
- Played with in the Sienkiewicz Trilogy. The Love Interest of each consecutive book gets kidnapped: Helena chooses to stab herself, Aleksandra is easily disarmed, only for a henchman she had saved earlier to brain the villain with a blunt object and Basia, having no dagger, uses a pistol as an improvised blunt weapon and deals a hit that costs the villain an eye.
- A Song of Ice and Fire:
Ygritte: A man can own a woman or a man can own a knife, but no man can own both.
- While Asha Greyjoy is far from a timid and ladylike virgin, she's still had to learn to defend herself in the No Woman's Land that is the Iron Islands (possibly more than most women, even, as her tomboyish attitude causes a lot of the men to want to "put her in her place"). She keeps a dagger in Victoria's Secret Compartment and an axe by her side at all times, and refers to the former as her "suckling babe" and the latter as her "husband" whenever men make allusions about her being unmarried and thus available.
- Ygritte says all wildling women know how to defend themselves from unwanted advances, and implies that even if you do manage to rape a wildling woman, she'll kill you in your sleep.
- In the Sword of Truth book Stone of Tears, Kahlan kills a would-be rapist with a ceremonial knife carved out of a human bone. She was half dead from poison at the time, and the book implies it wasn't her killing him, but the spirit of the man the bone used to belong to.
- In the first book of the Tales of the Otori, Kaede kills a feudal lord who tries to rape her with a needle hidden in her hair — a Chekhov's Gun given to her earlier for protection in those exact circumstances.
- In Thaïs of Athens, a rich merchant tries kidnapping Thais' beautiful slave girl Eris. What he doesn't know is that Eris is an ex-priestess of a dark goddess and keeps enough hidden blades on her (near naked) body to leave him and his cronies Gutted Like a Fish on the ground before they even touch her.
- In the Vorkosigan Saga, Barrayaran ladies traditionally carry "Vorfemme blades" (ornate concealable knives) for this purpose... And also, it is implied, to slit the throats of any mutant children they might bear. One character, musing on the tradition, points out that while the right to carry a dagger made you better armed than the peasants were allowed to be, your husband was allowed to carry two swords, so you were still outgunned; were the Vor lords really that scared of their ladies? Her companion reminds her of an ancestor of fearsome reputation, and she concedes that yes, perhaps the Lords should have been that afraid...
- Male version in Angel episode "Parting Gifts". Wesley shows he strapped a dagger to his thigh and boasts about being well prepared. During the big fight scene at the end, he is unable to unstrap it.
- Game of Thrones:
- Shae carries one in her garter on the night King's Landing is attacked by Stannis's fleet, insisting that she might not be chaste, but she won't be raped if the castle is taken.
- Catelyn Stark draws a knife when attacked by the Mountain Clans, though it's not clear if this is a last-ditch defense or to kill herself rather than face rape and a likely brutal death.
- The Star Trek Mirror Universe episodes heavily implied that this is one reason all of the women in the Mirror Universe carry daggers in those Bare Your Midriff outfits; not that any of them are chaste, but they clearly need to fend off rape in a Crapsack World where Might Makes Right. Uhura uses one to fend off Mirror Sulu's lecherous advances on her at one point.
- If you file the mass wedding as a kind of "political rape" (Aigyptos declared war on Danaos after all), the Danaides will qualify.
- The story of Telephus and Auge. Auge was a former lover of Heracles who was given to Telephus as a wife in reward for him saving a kingdom. Still faithful to Heracles, she brought a knife along in order to kill her husband. Fortunately, right before she stabs him (or, in some variants, simply before the consummation of marriage), a lightning bolt flashes between them. They start talking, and Telephus gets a legitimate reason to leave her alone - turns out he is the son Auge bore Hercules.
- The story of the founding of the Roman Republic involves the rape of a girl, Lucrecia, by the crown prince. After telling her family and local officials, she stabbed herself over the dishonor. This caused Lucius Junius Brutus to overthrow the monarchy and found the Republic.
- In 7th Sea, the bodice dagger is a popular weapon among Vodacce courtesans; many of whom are students of a swordsman school that specializes in the use of knives.
- In Ruddigore, when Robin as Sir Ruthven Murgatroyd has Hannah kidnapped, she pulls a small dagger with which she menaces him in swashbuckling style. She releases it only to pick up a much larger sword and continues to advance on him as he cries for mercy.
- King's Quest VI has a variant. Lady Celeste (daughter of the rulers of the Winged Ones) has one of these because she was being sacrificed to the Minotaur (it just didn't do her any good), and gives it to Alexander as a reward. Alexander has to smuggle it to Cassima, who is being threatened with a forced marriage to the Big Bad, who plans to marry her to secure the throne, then murder her after the wedding night. Cassima later uses it to cut her bonds and stab her Evil Vizier in the back, allowing Alexander to knock him out with a heavy ceremonial sword.
- In Medieval II: Total War, Princesses might start out with a "Delicate Blade" if their father has the Paranoid or Spymaster trait, a retinue item that increases their personal security when it comes to assassination attempts against them.
- Touhou: Sakuya keeps a mind-boggling number of daggers in two bandoliers around her thighs.
- Vampyr has Cristina Copa, a Whitechapel prostitute who carries a knife for self-defense (considering her line of work and the district she operates was haunted by Jack the Ripper, it makes sense).
- In old Spain, women used to carry a knife literally called "salvavirgo" (meaning "virginity-saver").
- A device invented in South Africa during a time when rape grew especially common was a combination of this and a chastity belt. Use your imagination.
- In the early days of train travel, ladies were advised to put pins in their mouth before entering a tunnel, lest a man attempt to steal a kiss in the darkness. Keeping a hatpin (think a six-inch needle) handy for The Chikan was also encouraged for both trains and buses.
- There's a reason teenage girls and young women (especially college students) are often encouraged to carry pocketknives or pepper spray when walking alone.
- An apocryphal story states that Genghis Khan died because he tried to rape a woman with scissors hidden in her, um, area.