Characters inserting a tied coin into a coin-operated device and then pulling the coin out with the string to steal an item or service from the machine. However, this trope also extends toward other things.
Later in the 1980s, when video game arcade operators realized that people were doing this, manufacturers started putting a string cutter into the coin mechanism. If you tugged back to try to hit the switch again, the string would cross the cutter and be severed by it, thus capturing the coin and preventing its reuse by the crooked customer. In modern times, coin-operated machines simply have a one-way ratchet, preventing the return of any coin once it has passed the counting mechanism.
A similar trick existed with banknotes and vending machines: attaching sellotape to the note, feeding it into the machine, then pulling it back out. Again, as with the coin string trick, this will not work on any machine built since the early 90s.
- One Carl Barks story features Donald Duck going to a valley to test echoes. His nephews set up a box where one can deposit a dime and expect an echo in exchange. The nephews just repeated whatever Donald said every time he put a dime in the box. It turns out that Donald was using the trick to get free echoes. They retaliate and eventually get the seven dimes.
- Kid Paddle tries this trick along with a variation: small discs of ice of the same diameter as a coin.
- One Garfield strip made use of this trick with a cookie, instead of a coin.
- In the 1920 movie The Scarecrow, Buster Keaton tricks the gas meter with a dime on a string.
- Yellowbeard: Commander Clement wants to get some information out of Harvey "Blind" Pew but doesn't want to pay for it. Each time he drops a coin into Pew's cup, he yanks it back out again with a string.
- In Real Genius, Val Kilmer's character uses liquid nitrogen to freeze water into rods the diameter of a quarter, then slices off slugs with a cutting tool to feed the vending machine.
- In The Black Spider-Knight Leopold XVII, to take a chance at slaying a dragonnote the eponymous knight needs to go through an automatic toll booth first, and the fee is a pocket of gold coins. Jamming a sword in the money slot doesn't help because it has apparently been built to withstand this kind of abuse from this setting's knights, so Leopold XVII tries this trick. The string is immediately cut by built-in automatic scissors.
- Recruits to the Ankh-Morpork City Watch were once given a coin, the King's Shilling, and sworn in on it when they gave their oath of service. In modern times, however, the Watch has become so stingy and under-financed that (even though a shilling is no longer quite so much moneynote ) the officers have a shilling on a string to perform the tradition on the cheap. At one point, Vimes (masquerading as a transfer officer from another city) twits an officer by grabbing the coin before he can pull it back.
- Halt and Catch Fire: Cameron uses a trick quarter on a string to play a Centipede machine for over an hour. She gets kicked out of the bar when patrons complain about her hogging the machine and the manager discovers Cameron's trick quarter.
- Red Dwarf: Rimmer tries this once, only to discover that the (sentient) vending machine is keen to this trick and equipped with an alarm. And a taste for Laser-Guided Karma.
- In the Shining Time Station episode, "A Dog's Life", Schemer uses this trick to try to find out where his nickels end up when someone puts them in the jukebox since he can never get any out of it. When he tries to pull it back out, Tito Swing holds onto it. When Tito lets go of the nickel at the request of the other members of the Jukebox Band, he causes Schemer to fall over.
- The Great Ace Attorney: Of a sort. In order to get free gas, Shamsphere used a threepenny coin to create an indentation on several bars of soap, filled them with some kind of liquid (usually water, but Soseki's tea on the night of his poisoning due to the water pipes being frozen), and left them outside in the cold weather to create fake ice-coins, and then paid the gas machine with those, with the hole he made at the bottom of the coinbox ensuring that when the coins melted, they would leak out and cover up their use.
- In Zork: The Undiscovered Underground, the protagonist has to use this trick to get the information they need out of a coin-operated Creator Cameo. It Only Works Once, though.
- Muse of Hello Wandering Star is shown doing this in one strip. She isn't particularly "heroic".
- SCP Foundation: Some of the experiments done on SCP-261 (a seemingly ordinary snack vending machine that dispenses random snack-type items ranging from mundane to bizarre) used a coin on a string. The machine at first responded by dispensing seemingly normal food items that caused the eater to promptly vomit them up, and eventually ended by simply dispensing a live grenade. The Foundation stopped testing the coin-on-a-string trick after that one.
- Done in the 1937 short Magic on Broadway. This was part of Paramount/Fleischer Novelty-Cartoon shorts which featured animation in part of it and live-action in the other half. The cartoon half of this entry has a slot-machine player cheating the machines in a penny-arcade by tying a string to the coin and pulling it out again. The machines get rather animated about being cheated and the petty-gambler receives some rough treatment.
- Similarly in the 1939 Porky Pig cartoon "The Film Fan."
- Bender from Futurama is fond of the coin-on-a-string trick.
- Looney Tunes and Merrie Meolidies:
- Chow Hound: A greedy bulldog, who had been bullying a cat and mouse to help him in his insatiable quest for all the meat (and gravy) in the world, uses a form of this a "cat on a string," if you will as the payoff of his scheme. Having held them hostage for weeks, the owners post "lost animal" ads in the newspaper, and when the dog collects the rewards (returning him in a trick bed), he yanks the cat away by yanking it by a string tied around his tail and sneaking away before the owners notice their cat is missing.
- SpongeBob SquarePants: In the Krusty Krab Training Video episode, a young Mr. Krabs uses coin-on-a-string trick method on a vending machine.
- Donald Duck:
- His early films has him using this technique (a la Mr. Krabs) to economize at a fair.
- In Modern Inventions, he uses this technique to enter the Museum of Modern Marvels for free. In the climax of the short, he attempts this technique again to get a free haircut from a robotic barber chair but ends up getting a humiliating makeover.
- In "Donald's Happy Birthday", when Donald forces his nephews to put their allowance in a bank, one of the nephews tries to do this to keep his coin, but Donald was one step ahead of him and cuts the string with scissors.
- Top Cat does the coin on a string trick during the opening credits; snatching the coin back from a doorman after he has tipped him.
- In the Warner Bros. cartoon short The Mouse that Jack Built, the mouse played by Jack Benny goes down to the cheese vault (counterpart to the money vault in the radio shows). He opens the first door by putting a coin on a string into a box, then pulling it up again. Since Jack Benny often played a cheapskate in his radio shows, this might have been to keep in character.
- A flashback on The Simpsons implies this helped Mr. Burns make his fortune.
- The Proud Family: Oscar Proud is cheap enough to do this to a sidewalk charity collector during a Christmas special. Penny isn't impressed.
- Dastardly and Muttley in Their Flying Machines: In "Operation: Anvil," Dastardly relieves Muttley of his medal after he botches an operation to catch Yankee Doodle Pigeon. Muttley had a string tied to the medal, so as Dastardly walks off, Muttley yanks the medal back.
- The Goof Troop episode "Maximum Insecurity" had Leech use the coin-on-a-string trick to snag a free soda from a vending machine. PJ then runs into him and gets him mad by breaking the string and making him lose the coin it was tied to.
- Whatever Happened to... Robot Jones?:
- The episode "Vacation" shows Robot's friend Cubey use the coin-on-a-string trick while at Nob's Arkaid.
- In "Hookie 101", Mitch uses the coin-on-a-string trick as a solution for when the gang are at the arcade after being tricked out of most of their money and using the remainder to help out a monster living in an ice machine.
- The Fairly OddParents episode "The Big Problem" features this in an Imagine Spot Timmy has where he is an adult. One scene depicted in the sequence is his babysitter Vicky living on the streets now that he's too old to need her looking after her. Adult Timmy appears to put a coin into Vicky's begging cup, but then yanks the coin away by the string it's tied to and yells "Psyche!"