Short-Change Swindles[]
On the simple level, you have the short-change swindle. This is something you do to merchants—or merchants do to you! Through fast-talk, distraction and sleight-of-hand, you trick them into giving you as change more money than you paid them.
The story at the end of this chapter illustrates the short-change swindle.
Gambling[]
Gambling is a finer racket. Gambling is irresistible to many people, and the swindler loves to take advantage of this weakness. Every sort of gambling—dice, coin-matching, the shell game, races and gladiatorial contests (the fantasy equivalent of modern organized sports)—presents an opportunity for the swindler to make a load of silver. A swindler needs gambling proficiency to work any of the following scams, and any other character who makes a gambling proficiency check will probably be wise to the swindler's tricks.
Dice Games: Dice-throwing developed in ancient times, and has remained popular since (even into RPGs). An astute gambler understands the odds of winning in any dice game, such as craps, and a skilled swindler knows how to rig the game in his favor. Loaded dice (with imperceptibly rounded faces, or weighted pips, and so forth) are one way, but the true master can even throw dice so that they will land as he wishes. To do this trick, a swindler must make a successful pick pockets roll, at -40%, for each die.
Coin Matching: Coin matching is a simple, age-old game, appearing in various forms since the days of the pharaohs, and is simple to run a scam around.
The favorite variation for two swindlers working a sucker is "odd man wins"; Three coins are tossed, or revealed simultaneously (like the rock-paper-scissors game). If two are heads or tails, and the other is the opposite, the holder of the odd coin wins. If all three are the same, no one wins.
To set this up as a scam, there should be two swindlers. One plays the steerer, gaining the confidence of the pigeon, while the other pretends to be a foolish stranger. The steerer conspires with the real target, ostensibly to swindle the money of the stranger, his true partner. In the course of the game, the steerer winds up with all the money.
Of course, he's not able simply to share it with the pigeon, since they've supposedly just pulled a fast one on the foolish stranger. They have instead agreed beforehand to meet somewhere and share the spoils. Of course, the steerer never shows up to share and the would-be con artist is left penniless. Furthermore, since he was duped on account of his own greed, trying to do what was done to him, he'll probably swallow his chagrin and never report the incident to the local authorities!
The Shell Game: The shell game is another age-old classic. The swindler sets up at some event, like a circus, fair, or even a busy street corner. He has a single pea and three shells, which he rearranges. It is a test of observation, he says: Anyone who can identify which shell covers the pea, after they've been shifted around, will win whatever he bet. If he guesses wrong, he loses his money.
Someone takes on the challenge, and wins! Of course, this is an accomplice of the shell man (known as a "capper"). The crowd thinks the swindler is playing honestly. Then a real target places his bet. He, too, will win. The swindler will nurse the target's self-confidence to raise the stakes, and then (mysteriously!) the victim's powers of observation will decline, and he'll fail to spot the right shell! This of course is done through sleight-of-hand. (To do it unnoticed, the thief needs to make a successful pick pockets roll.)
Quackery[]
Quackery is the realm of the mountebank, the seller of "snake oil" and all manner of exotic potions, unguents and charms, each supposed to be a medical wonder, but usually worthless (if not actually dangerous to its user). Even in a world where magic is real, quacks can make brisk profits from those who cannot tell a real potion from fake.
Forgery and Counterfeiting[]
Forgery may also be a swindler's calling, including counterfeiting. Interestingly, forgery was not a serious crime in the middle ages; barter took precedence above coinage or credit notes, and it's hard to counterfeit a bushel of wheat or forge livestock.
As the Renaissance came, however, and banking developed, so did the forger's art—and the punishments became serious. As late as the first half of the 19th century in England, men and women were hanged for the crime of forging one-pound notes.
The value of forgery, therefore, and the risks involved, will depend on the nature of commerce and trade in your campaign.
Jewelry Swindles[]
For the well-trained rogue, jewelry swindles can be both the most lucrative and the easiest, because it is so difficult for the untrained eye to identify or to judge the value of a precious stone. Besides dealing in paste and glass fakes, jewelry swindlers may pass off a lesser stone as something more valuable (e.g., quartz for diamond), or pay someone (especially naive but treasure-laden adventurers) for a diamond as if it were quartz. A nimble-fingered rogue may also replace fake jewels for real ones, and the owner may never know the difference!
Sly NPC jewel swindlers are a great way for DMs to relieve characters lacking gem cutting proficiency of their cash and jewels (provided they don't spew out at the start, "The dragon's treasure includes 12 opals at 1,000 gp each").