The elaboration of the shell game called cups-and–balls came into being in Europe in the 12th century A.D.   It was probably a side-issue of the poker strategy game of bilboquet played by children, in which a cup on the end of a stick is used to catch a ball attached to it by a string.  The cups (inverted on a table) can, of course, be used in exactly the same way as shells.  The elaboration came with the use of three cups and two colored balls.  The balls could be made to seem to move from one cup to another by false pockets in the cups (as in the egg-bag trick used by modern conjurers).

Later still, thimbles and a pea were used, and the cheat working the game came to be known as a “thimble-cove” or “Thimple-rigger.”  Villainy unmask’d, an anonymous book published  in London in 1752, warns its readers especially against the dangers of betting tips on which of the thimbles the pea will be under:  “It is under none of them.”  But, as the British sociological journalist Henry Mayhew noted in London Labour and the London Poor (1851). The warning apparently wasn’t taken; for by then “the thimble trick” had assumed the status of an open street game.

During the 19th century, American confidence  men on Mississippi river boats used walnut shells and a pea or ball of paper, varied with the three-card trick.  The American historian John O’Connor says that the down-river passengers “allowed themselves to be fooled by any simplicity, but that on the journey back a greater degree of sophistry was needed.”  The river-boat swindlers also enticed the innocent travelers (according to O’Connor) into games of chase-the-queen,  “setting up their trays in the best positions under the winnings and seeing to it that their partners set amongst the passengers were of good dress and mien.”

A more modern version of the game is play today with bottle caps from beer or Coca Cola bottles.  Wherever it’s played, the innocent who believes that his eyes are sharp enough to follow the movements of the shell, bottle cap, or queen, or that because he has spotted a bent corner on the key card he has an advantage over the operated well, he’ll learn.
The innocent stands a better chance in the widely played match game (mora in Italy; and atep, still, in Egypt, even though matches are now used rather than fingers), for cheating is not an invariable feature of its operations.  The match game is wholly a guessing game, but your chances of winning are proportionate to your mathematical and psychological abilities.  Broadly, the object of the game is for one player to guess the total number of matches held in the right hands of all the other players.  He bases his guess on the knowledge that each player has three matches and may conceal none, one, two, or all of them in his right hand.  Any number can play.
Organized match games at Baden, Macao, Las Vegas, and other gambling centers usually have six players and big stakes.  But wherever the game is played by people, it is also played informally for small stakes such as rounds of drinks or bus fares.  The rules are simple: Each player must have an opportunity to be last caller in a series of games (because the last player to call his guess has distinct mathematical and psychological advantages); and bluffing can be as important as it is in poker.

A late 19th century version of Charles Fey’s first slot machine.  Left a simplied diagram of a slot machine’s mechanism.  The coin starts a timing device (A) that turns a rod (B) like a clock’s hands.  One device governs each of three reels; pulling the handle spins the reels, and after a few seconds the rods stops them.

In all games of pure chance, for that matter,the rules of play are simple-which is why they attract such vast numbers of amateur (but determined ) players.  One of the simplest gambles, known all over the world, is the slot machine (called the “fruit machine” in Britain – and also, practically everywhere, called the “one-armed bandit”).

As nearly everyone knows, the slot machine is a mechanical device that absorbs coins.  Each coin inserted allows the player to pull a lever that sets three independent vertical reels spinning.  The peripheries of the reels bear colored symbols (some of them representations of fruit), and if they come to rest with specified combinations of symbols running parallel to a “payoff line,” the machine dispenses some of its coins to the player.  The player backs nothing but the chance that his pull on the lever will bring the reels to rest at a favorable combination.  The slot machines can be geared to pay back any percentage of the coins it absorbs – 82 to 94 per cent being as fair as you can find.  There are 20 symbols on each reel, which means that there are 8000 possible combinations of symbols.  But only 12 of these will pay back any coins.