Chain Letter

""Chain letters," said the Tyrant. "The Chain Letter to the Ephebians. Forget Your Gods. Be Subjugated. Learn to Fear. Do not break the chain -- the last people who did woke up one morning to find fifty thousand armed men on their lawn.""

- (Terry Pratchett, Small Gods)

Bob receives a letter, one which informs the recipient that he must mail it to a certain number of people or suffer bad luck. Though warned by his credulous friends, the skeptical Bob mocks the very concept of luck, and vows to ignore it. Disaster proceeds to befall him on a scale which would make Job look like a paragon of good fortune.

In real life Chain Letters have nowhere near the credibility that they do in media, and are annoyingly common in e-mail spam and on comment pages and message boards.

Anime

 * Occurred in an episode of Great Teacher Onizuka.
 * In Axis Powers Hetalia Russia got one saying that if he not mail it to three other people within three days his capital will become Warsaw. Poland, points out that, since he doesn't have friends, he'll freak out. It doesn't work since Russia just send it to his subordinates instead.

Comics

 * Charlie Brown (of course) once got a chain letter and agonized about sending it or not. He finally decides to tear it up. Then it starts raining.
 * Even The Wizard of Id had a chain letter arc.

Fan Fic

 * Calvin and Hobbes: The Series: "Chains" revolves around Calvin and Susie receiving these. Susie rips hers up, and proceeds to have bad luck for the rest of the episode.

Film

 * Premise of the 2010 Slasher Film Chain Letter was that if the characters didn't forward the chain letter, they would die agonizing death involving...chains.

Literature

 * In the Baby-Sitters Club book "Mary Anne's Bad-Luck Mystery" the club starts having bad luck after Mary Anne throws out a chain letter.

Live-Action Television

 * This is a staple of Sit Coms and has been for decades, as such, nearly every sitcom that ran long enough has had at least one episode about a chain letter.
 * A rare Common Sense moment had Red of The Red Green Show ignoring a recent chain letter craze over the Lodge until Dalton pointed out that Harold, who started it, got a $100 bill from it. By the final act, chain letters are going out like crazy until Harold reveals he didn't get a $100 bill - it was a bill for $100 from the library. It also provides a rare case of the sender getting the bad luck, not just from the bill, but from the others dipping into his cash box to pay for all the letters.
 * In an episode of Home Improvement, Unlucky Tim eventually realizes that his ill fortune isn't caused by the letter but rather that, owing to his incompetence, bad stuff always happens to him.
 * In a 3rd Rock from the Sun episode, both Dick and Mary receive chain letters. Mary throws hers out right away and tells Dick to do the same. Dick ambivalently holds on to his and leans more and more toward sending it out when Mary is repeatedly hit by bad luck. Eventually, Dick ends up taking superstitions seriously to such an outrageous degree that they totally run his life.
 * Wings (from a later, crappy season): Unlucky Antonio.
 * Sabrina the Teenage Witch, unlucky Hilda and Zelda.
 * A Kids in The Hall sketch had a company's CEO presenting a chain letter to his board and asking them what to do. Only one character (the recurring Danny Husk) refuses to take it seriously.
 * One episode of The Facts of Life saw the girls neglect the store's upcoming health inspection because they were so involved with a chain letter. Jo also accidentally sent the money for the chain letter to the health inspector, who thought it was a bribe.
 * An episode of an Australian news parody show (the name escapes currently) had one short about a man who refused to sign a chain email that said, 'if you don't pass this on, a little boy will die'. He ignored it. The boy died, and the man is being held accountable for manslaughter.
 * In an episode of iCarly, Freddie gets a chain letter regarding Consuelo, a Spanish woman who had died. He must pass it on, or suffer such misfortunes as red socks getting mixed with white shorts, his sandwich getting run over, making it absolutely gigantic (at least the size of his torso), and his computer shorting out and making weird popping sounds.
 * Subverted though, because Sam caused all that misfortune. Freddie catches her in the act though and gets back at her at the end of the episode.
 * An episode of Ghost Whisperer centered around the ghost of a teenage girl who was assaulting people who received a chain letter and didn't forward it.
 * An All in The Family episode has this happening to Archie.
 * The Andy Griffith Show has an episode where Barney gets one of these, Andy convinces him to throw it out, and...well, you can guess the rest.
 * The Mary Tyler Moore Show has an episode where Mary gets one of these from Lou Grant.

Web Original

 * In Suburban Knights,

Western Animation

 * ¡Mucha Lucha!, "Chain of Fools"
 * One episode of Pinky and The Brain began with Brain planning to send a chain letter as part of his latest plan. He was beaten to the punch by his sworn enemy, Snowball.
 * In a 6teen episode, Jen gets a chain email, ignores it, and has bad luck throughout the episode. She then tries to get a number of people's email addresses, but later it is revealed those people have Jen's email address, so she has more chain letters to send.
 * Dr. Katz, Professional Therapist has an episode where Ben gets one.

"12 facts I know about u 1. Your reading my trope 2. Now your saying/thinking thats a stupid fact. 4. You didnt notice that i skipped 3. 5. Your checking it now. 6. Your smiling. 7. Your still reading my trope. 8. You know all you have read is true. 10. You didnt﻿ notice that i skipped 9. 11. Your checking it now. 12. You didnt notice there are only 10 facts Copy and paste to 1 trope, Then stick your name on the list and tomorrow will be your best day ever! no matter what if you dont copy this to 300 trops in the next minute youll just drop out of your seat"

"Why would I just fall off of my seat?!"

"That's stu...*thunk*"