Ooh, a fun topic. A lot of information can be gotten by reading the rather famous novel the Grifters, by Jim Thompson.
I don’t know too much about big cons like in The Sting, since they weren’t too common – they required a lot of investment and too many things could go wrong. It took real balls, and that’s why the kid has to track down Gondorff. Guys like him are rare, and they don’t advertise.
Another problem with discussing long cons is that they’re hard to discern from other kinds of shady business. They’re big enough that they have to at least look respectable from the outside.
Most operators worked the short con, since it was easy, quick, and there wasn’t much investment. Classics include three-card monte, the twenties, the tat, and the slap (or smack).
I assume 3-card monte is familiar enough that I don’t need to explain it – the damn con turns up on just about every TV show with street scenes, and I’ve seen it done in person.
The Twenties: go to a store and buy a trivial amount of stuff – less than $1 worth. Pay for it with a $20 bill and get the change, while muttering to yourself about having the exact change. After you get your money, you “luckily” find the change and give it to the clerk and ask for your $20 back. If this works, you double your money. If it doesn’t, hopefully you’ve put on a good enough act that it seems like an honest mistake.
The Tat: Accidentally bump into somebody at a bar, causing him to spill his drink. Act friendly and apologetic, and buy him another round or two to make up for it; hopefully the victim will offer to buy you one now. Get “distracted” and suddenly “find” a lost die on the floor. Start playing a friendly game, rolling each other for the price of the drinks. Keep doubling the bets. Of course, you’re adept at throwing dice and never let it actually roll – but you keep it looking honest. As the bets double, eventually you can strip even somebody with lots of money down to nothing – all on a friendly wager.
The Smack: Flipping coins and comparing the results, betting on the outcome. But your coin is ever-so-slightly filed down on one side, and you’ve practiced being able to tell which face is up by how it feels on your wrist.
That’s the extent of my knowledge at this late hour. I’m sure somebody else has more and better info than I do.