A slot machine, known in Australia as a poker machine, or in the United Kingdom as a fruit machine is a certain type of gambling machine. Classically, a slot machine is a coin-operated machine with three or more reels that rotate when a lever on the side of the machine is pulled. (The slot machine is also known informally as a one-armed bandit because of its appearance.) The machine typically pays off based on patterns of symbols visible on the front of the machine when it stops. Modern computer technology has resulted in many variations on the slot machine concept. Today, slot machines have become one of the most popular attractions in casinos.

History

The slot machine was invented in 1895 by Charles Fey of San Francisco, California. The first machine, known as Liberty Bell, had pictures of diamonds, hearts, spades, and cracked Liberty Bells on three mechanical reels. Liberty Bell was a huge success and spawned a thriving mechanical gaming device industry. Another early machine gave out winning in the form of fruit flavoured chewing gums with pictures of the flavours as symbols on the reels. The popular cherry and melon symbols derive from this machine. The "BAR" symbol now common in slot machines was derived from an early logo of the Bell-Fruit Gum Company. In 1964, Bally developed the first fully electromechanical slot machine called Money Honey.

Description

A person playing a slot machine purchases the right to play by inserting coins, cash, a debit card, or in newer machines, a bar-coded paper ticket (known as "ticket in/ticket out" machines), into a designated slot on the machine. The machine is then activated by means of a lever or button, or on newer machines, by pressing a touchscreen on its face. The game itself may or may not involve skill on the player's part -- or it may create the illusion of involving skill without actually being anything else than a game of chance.

The object of the game is to win money from the machine. The game usually involves matching symbols, either on mechanical reels which spin and stop to reveal one or several symbols, or on a video screen. The symbols are usually brightly colored and easily recognizable, such as images of fruits, and simple shapes such as bells, diamonds, or hearts.

Most games have a variety of winning combinations of symbols, often posted on the face of the machine. If a player matches a combination according to the rules of the game, the slot machine pays the player cash or some other sort of value, such as extra games.

There are many different kinds of gambling slot machines in places such as Las Vegas. Some of the most popular are the video poker machines, in which players hope to obtain a set of symbols corresponding to a winning poker hand. There are standard 5-card draw machines, all the way up to 100-play machines, where you can play 100 hands at a time.

Becoming more popular now are the 9 line slots. Usually these are themed slots (Addams Family, I Dream of Jeannie, etc.) with a bonus round. Most accept variable amounts of credit to play with 1 to 5 credits per line being typical. The higher the amount bet, the higher the payout.

Of course, there are the standard 3 - 5 reel slot machines, of various types. These are the typical "one-armed bandits".

Larger casinos offer slot machines with denominations from $.01 (penny slots) all the way up to $100.00 a pull. Large denomination slot machines are usually cordoned off from the rest of the casino into a "High Limit" area, often with a separate team of hosts to cater to the needs of the high-rollers who play there.

Technology

It is a common belief that the odds on a machine have something to do with the number of each kind of symbol on each reel, but this is not the case. Modern slot machines are computerized, so that the odds are whatever they are programmed to be. For instance, if the jackpot combination is "7-7-7", slot machine owners can fool/tease people by making "7-7-(non-7)" come up frequently. Even if the machine uses real wheels, the symbols shown by the wheels are chosen by computer.

Slot machines are typically programmed to pay out around 82-94% of the money that goes into them as winnings. This can often be changed by the owner with the aid of DIP switches on the motherboard. The winning patterns on slot machines, the amounts they pay, and the frequency at which they appear are carefully selected to yield a certain percentage of the cost of play to the "house" (the operator of the slot machine), while returning the rest to the player during play. Suppose that a certain slot machine costs $1 per spin. It can be calculated that over a sufficiently long period, such as 1,000,000 spins, that the machine will return an average of $950,000 to its players, who have inserted $1,000,000 during that time. In this (simplified) example, the slot machine is said to pay out 95%. The operator keeps the remaining $50,000.

Slot machines common in casinos at this time are more complicated. Most allow players to accept their winnings as credits which may be "spent" on additional spins.

Often machines are linked together in a way that allows a group of machines to offer a particularly large prize, or "jackpot". Each slot machine in the group contributes a small amount to this progressive jackpot, which is awarded to a player who gets (for example) a royal flush on a video poker machine, or a specific combination of symbols on a regular or 9 line slot machine. The amount paid for the progressive jackpot is usually far higher than any single slot machine could pay on its own. As of this writing, Megabucks (a 5-reel dollar slot machine) pays a minimum jackpot of several million dollars when a player bets $3 and get the symbols for the top jackpot.

American slot machines

In the United States, the public and private availability of slot machines is highly regulated by state governments. Nevada is the only state that has no significant restrictions against slot machines both for public and private use. In New Jersey, slot machines are only allowed in casinos operated in Atlantic City. Several states (Illinois, Indiana, Iowa, Louisiana, Mississippi, and Missouri) allow slot machines (as well as any casino-style gambling) only on licensed riverboats. Native American casinos on reservations cannot have true slot machines unless allowed by the state that the tribal casino is located in (per Indian Gaming Act).

For a list of state by state regulations on private slot machine ownership, see Slot machine (U.S. state ownership regulations)

Slot clubs

Many American casinos offer free memberships in "slot clubs", which return a small percentage of the amount of money that is bet in the form of "comps" (complementary food, drinks, hotel rooms, or merchandise), or sometimes as cash back (sometimes with a restriction that the cash be redeemed at a later date). These clubs require that players use a card that is inserted into the slot machine, to allow the casino to track the player's "action" (how much the player bets and for how long), which is often used to establish a level of play that may make a player eligible for additional comps. Comps or cash back from these clubs can make a significant difference in the maximum theoretical return when playing slot machines over a long period of time.

Australian slot machines

Called poker machines or "pokies" in Australia, the country has one of the highest concentration of poker machines per head of population in the world, with changes in regulations leading to a profusion of poker machine venues across the country. Various objectors, including many branches of the clergy and also charities for the poor, have criticised the spread of the machines, as they claim that it has led to a huge rise in the levels of "problem gambling" - gambling to a level that causes financial and social stress to the gambler and their families, as well as the general levels of gambling.

Australian-style poker machines use video displays to simulate (usually) five physical reels. These machines also have additional bonusing and second-screen features such as free games and bonus levels. They also allow for multiple lines (up to 50) or multiple ways (up to 243 ways) to be played. This higher level of complexity has meant that greater revenues can be obtained by operators, but also that the potential for problem gambling to develop is increased.

Poker machines are found in casinos (approximately one in each major city) as well as pubs and clubs (usually sports, social, or RSL clubs). This greater accessibililty is also seen as a potential contributor to problem gambling.

Most problem gamblers attending counselling through Gamblers Help (http://www.ghsouthern.org.au) report poker machines as the problematic form of gambling. Due to this there is a significant focus on the regulation of poker machines, and many groups are advocating for legislative change.

European slot machines

Slot machines are often known as fruit machines in Britain. Slot machines are commonly found in pubs, arcades, and some take-away food shops. These machines commonly have 3 or 6 reels with around 16 or 24 fruit symbols printed around them. These reels are spun, and if certain combinations of fruit appear, winnings are paid from the machine, or subgames are played. These are very similar to slot machines seen in casinos and elsewhere around the world, but the term "fruit machine" is usually applied to a type of machine more commonly found in pubs and arcades. These games have lots of extra features, trails and subgames with opportunities to win money, usually more than can be won from just the reels. However, the jackpots from these fruit machines are strictly limited with many machines paying no more than a maximum of £25 in any one win.

These machines also operate in a different fashion to American slot machines; whereas slots are programmed to pay a percentage over the long-run, there is no reason why a jackpot cannot be paid straight after one has already been won - this is because over the long-run the percentage payout will be the same. However, in the UK, a fruit machine takes on an amount above its payout percentage before winning, so if a payout is 95%, a machine will make the player lose £10 before paying out £9.50. As such, it is sensible to watch for people playing these machines but not winning as the likelihood of a win increases.

This type of fruit machine is popular across Europe (in the countries where they are legal), and very popular in countries such as the Czech Republic, Russia, and Ukraine.