Good for Bad is The Tale of a Con Man that involves arranging a swap of something genuine for something bogus. You give me one dollar of real money for my counterfeit fifty. Better yet, if you have an art masterpiece, I can get you a good replica for your insurance fire.
No art work? OK. I know a guy who has identical twin racehorses. One can really run, the other, not so much. He needs someone to place his bets for him, after he uses the slow horse to boost the odds, then swaps in the fast horse on the sly.
Not a gambler? Smart man! Hey I've got some British pounds here that aren't supposed to be in the country. Since you are going to London on vacation, howabout we swap for American, at about half the British face value?
What? No, man, nobody can counterfeit British money; it's too tough. I just want to avoid any embarrassing conversations with the IRS ...
Good For Bad always uses a switch. That is, the bad thing is swapped in for the good thing, without the mark knowing, often using sleight of hand or switching identical bags. The counterfeit money that is being sold looks so good because it is real money, but it isn't what goes into the bag at the exchange. The "fast" horse twin is the same horse, on drugs. The last time you ever see the real art masterpiece is when you give it over to be replicated.
- The Ring Scam is one of the traditional good-for-bad cons. The con man offers to sell the mark a diamond ring for a few hundred dollars. The con man allows the mark to take it to a jeweller and get it examined — at which point the jeweller assesses the ring at much more than the asking price; it's a real ring worth thousands. The Mark's greed is turned against him, encouraging him to run outside and agree to the deal. The con man will use some pretext to get his hands on the ring, and switch it for a glass lookalike worth about five dollars, selling the worthless duplicate for his original asking price. An early version of this scam involving a gold-plated brass ring is known as "fawney rig".
- This scam is thought to be the root of the word "phony" for "fake". The root comes from the Irish word "fáinne"* , which means "ring".
- Peewit in The Smurfs and the Magic Flute tries and fails to swap out one of the magic flutes for a fake.
- Ocean's Eleven:
- Ocean's Twelve intended to do this to the Coronation Egg-swap out the real egg for a hologram-before a rival thief, Francois Toulour, beat them to it and won a bet. The twist was they already switched the real egg for a fake one while the real one was transported by a nondescript courier.
- Played with in Ocean's Thirteen, where Linus and his father swapped out Willy Bank's Five Diamond awards for fakes, only for Toulour to steal them from him. He actually stole the fakes. Linus actually was there to plant bombs around the case the diamonds were in to steal the entire case, diamonds and all.
- In Catch Me If You Can, Frank Abagnale thinks he found an attractive woman willing to take a romp with him only for her to reveal herself as a high-class prostitute. Frank turns the tables on her, by overpaying her with a phony cashier's check and receives his change in cash, effectively tricking a gorgeous hooker into paying him $400 for a night of testing the hotel's bedsprings. According to Frank Abagnale's book (which was the basis for the movie), this incident ultimately cost him big-time as the hooker gave the FBI a description of him, something they didn't have before then.
- This is used in the Discworld novel Going Postal, in which conman Moist von Lipwig views a real ring and a fake ring as part of his basic tools for emergencies. When the man wants to have it valued and they go to an actual jeweler he shows the man a real diamond ring. Reassured that it's real the mark then buys the ring, and when he takes it back to the jeweler to sell he's informed that it's brass and glass.
- His backup plan, if he can't source the real ring, is to walk through the motions of this con... and then make the trade almost immediately thereafter, without any time for a switch, with the aim of proving to the mark that this relatively well-known con isn't going on. The trick here is that Moist bribed the jeweler ahead of time to testify that his glass ring was real.
- Happens to Bertie Wooster in the short story "Pearls Mean Tears". Fortunately Jeeves isn't as easy to dupe.
- In Investment Biker, Jim Rogers remembers how in developing countries he would change money with black-market street vendors (who would give him fake notes maybe one time out of twenty) rather than official banks (who would take ten or twenty percent as commission on every transaction.)
- In The Rockford Files, Jim Rockford uses one of these to recover a stolen pearl necklace. He uses a fake jeweler to convince the thieves that the necklace they stole was a fake, then convinced them to break back in and switch it for one that actually was fake.
- Mission: Impossible does this often.
- On M*A*S*H Frank buys a string of real pearls for his wife and fakes for Margaret. She cons him into switching them.
- Fed up with Suzanne bragging about her pearls, Mary Jo on Designing Women swaps them out for cheap fakes...then loses the real ones.
- White Collar plays this trope a lot.
- An old woman goes into a poultry shop and asks for a duck (the last one in the shop). The shopkeep presents it to her, but she says it's a bit scrawny, so he takes it in the back, hooks it to a bicycle pump and puffs it up a little. He triumphantly returns, only for the old lady to change her mind and decide she'll take both of them.
- Truth in Television with any "traditional medicine" that used the parts of endangered species. For example, powdered rhino horn is considered an aphrodisiac. Not only is the claim bullshit, but they almost always use substitutes like cow bone for the actual powder. They always SHOW you the horn, but not the grinding process. And, unfortunately, this fact doesn't stop the poaching of actual rhinos for their horns.
- Used as part of the "bait and switch" scheme. Bait-and-switch involves a business luring customers in notice of a good or service; upon arrival, the advertised good or service is not available but instead the customers get offered one that is more expensive and/or is of poorer quality.
- The pigeon drop is a classic two-person con. Here's one variant. The mark is given a chance to split a sudden windfall. They're asked for good faith money to keep them honest, but the con-man swaps the windfall with something worthless. The classic version is finding a wallet or envelope full of money which the conmen offer to share after checking with the cops or asking at some place if anyone lost it. They ask for good faith money and switch the wallet/envelope with one full of paper. They then leave the mark convinced he is holding the cash and make off with the good faith money.