Pachislot

A slot machine (American English), fruit machine (British English) or poker machine (Australian English and New Zealand English) is a gambling machine that creates a game of chance for its customers. Slot machines are also known pejoratively as one-armed bandits because of the large mechanical levers affixed to the sides of early mechanical machines and the games' ability to empty players' pockets and wallets as thieves would.

A slot machine's standard layout features a screen displaying three or more reels that "spin" when the game is activated. Some modern slot machines still include a lever as a skeuomorphic design trait to trigger play. However, the mechanics of early machines have been superseded by random number generators, and most are now operated using buttons and touchscreens.

Slot machines include one or more currency detectors that validate the form of payment, whether coin, cash, voucher, or token. The machine pays out according to the pattern of symbols displayed when the reels stop "spinning". Slot machines are the most popular gambling method in casinos and constitute about 70% of the average U.S. casino's income.

Digital technology has resulted in variations in the original slot machine concept. As the player is essentially playing a video game, manufacturers can offer more interactive elements, such as advanced bonus rounds and more varied video graphics.

Etymology

The "slot machine" term derives from the slots on the machine for inserting and retrieving coins. "Fruit machine" comes from the traditional fruit images on the spinning reels such as lemons and cherries.

History

Sittman and Pitt of Brooklyn, New York developed a gambling machine in 1891 that was a precursor to the modern slot machine. It contained five drums holding a total of 50 card faces and was based on poker. The machine proved extremely popular, and soon many bars in the city had one or more of them. Players would insert a nickel and pull a lever, which would spin the drums and the cards that they held, the player hoping for a good poker hand. There was no direct payout mechanism, so a pair of kings might get the player a free beer, whereas a royal flush could pay out cigars or drinks; the prizes were wholly dependent upon what the establishment would offer. To improve the odds for the house, two cards were typically removed from the deck, the ten of spades and the jack of hearts, doubling the odds against winning a royal flush. The drums could also be rearranged to further reduce a player's chance of winning.

Because of the vast number of possible wins in the original poker-based game, it proved practically impossible to make a machine capable of awarding an automatic payout for all possible winning combinations. At some time between 1887 and 1895, Charles Fey of San Francisco, California devised a much simpler automatic mechanism with three spinning reels containing a total of five symbols: horseshoes, diamonds, spades, hearts and a Liberty Bell; the bell gave the machine its name. By replacing ten cards with five symbols and using three reels instead of five drums, the complexity of reading a win was considerably reduced, allowing Fey to design an effective automatic payout mechanism. Three bells in a row produced the biggest payoff, ten nickels (50¢). Liberty Bell was a huge success and spawned a thriving mechanical gaming device industry. After a few years, the devices were banned in California, but Fey still could not keep up with the demand for them from elsewhere. The Liberty Bell machine was so popular that it was copied by many slot machine manufacturers. The first of these, also called the "Liberty Bell", was produced by the manufacturer Herbert Mills in 1907. By 1908, many "bell" machines had been installed in most cigar stores, saloons, bowling alleys, brothels and barber shops. Early machines, including an 1899 Liberty Bell, are now part of the Nevada State Museum's Fey Collection.

The first Liberty Bell machines produced by Mills used the same symbols on the reels as did Charles Fey's original. Soon afterward, another version was produced with patriotic symbols, such as flags and wreaths, on the wheels. Later, a similar machine called the Operator's Bell was produced that included the option of adding a gum-vending attachment. As the gum offered was fruit-flavored, fruit symbols were placed on the reels: lemons, cherries, oranges and plums. A bell was retained, and a picture of a stick of Bell-Fruit Gum, the origin of the bar symbol, was also present. This set of symbols proved highly popular and was used by other companies that began to make their own slot machines: Caille, Watling, Jennings and Pace.

A commonly used technique to avoid gambling laws in several states was to award food prizes. For this reason, several gumball and other vending machines were regarded with mistrust by the courts. The two Iowa cases of ''State v. Ellis'' and ''State v. Striggles'' are both used in criminal law classes to illustrate the concept of reliance upon authority as it relates to the axiomatic ''ignorantia juris non excusat'' ("ignorance of the law is no excuse"). In these cases, a mint vending machine was declared to be a gambling device because the machine would, by internally manufactured chance, occasionally give the next user several tokens exchangeable for more candy. Despite the display of the result of the next use on the machine, the courts ruled that " e machine appealed to the player's propensity to gamble, and that is vice."

In 1963, Bally developed the first fully electromechanical slot machine called Money Honey (although earlier machines such as Bally's High Hand draw-poker machine had exhibited the basics of electromechanical construction as early as 1940). Its electromechanical workings made Money Honey the first slot machine with a bottomless hopper and automatic payout of up to 500 coins without the help of an attendant. The popularity of this machine led to the increasing predominance of electronic games, with the side lever soon becoming vestigial.

The first video slot machine was developed in 1976 in Kearny Mesa, California by the Las Vegas–based Fortune Coin Co. This machine used a modified Sony Trinitron color receiver for the display and logic boards for all slot-machine functions. The prototype was mounted in a full-size, show-ready slot-machine cabinet. The first production units went on trial at the Las Vegas Hilton Hotel. After some modifications to defeat cheating attempts, the video slot machine was approved by the Nevada State Gaming Commission and eventually found popularity on the Las Vegas Strip and in downtown casinos. Fortune Coin Co. and its video slot-machine technology were purchased by IGT (International Gaming Technology) in 1978.

The first American video slot machine to offer a "second screen" bonus round was Reel ’Em In, developed by WMS Industries in 1996. This type of machine had appeared in Australia from at least 1994 with the Three Bags Full game. With this type of machine, the display changes to provide a different game in which an additional payout may be awarded.

Operation

Depending on the machine, the player can insert cash or, in "ticket-in, ticket-out" machines, a paper ticket with a barcode, into a designated slot on the machine. The machine is then activated by means of a lever or button (either physical or on a touchscreen), which activates reels that spin and stop to rearrange the symbols. If a player matches a winning combination of symbols, the player earns credits based on the paytable. Symbols vary depending on the theme of the machine. Classic symbols include objects such as fruits, bells, and stylized lucky sevens. Most slot games have a theme, such as a specific aesthetic, location, or character. Symbols and other bonus features of the game are typically aligned with the theme. Some themes are licensed from popular media franchises, including films, television series (including game shows such as ''Wheel of Fortune''), entertainers, and musicians.

Multi-line slot machines have become more popular since the 1990s. These machines have more than one payline, meaning that visible symbols that are not aligned on the main horizontal may be considered as winning combinations. Traditional three-reel slot machines commonly have one, three, or five paylines while video slot machines may have 9, 15, 25, or as many as 1024 different paylines. Most accept variable numbers of credits to play, with 1 to 15 credits per line being typical. The higher the amount bet, the higher the payout will be if the player wins.

One of the main differences between video slot machines and reel machines is in the way payouts are calculated. With reel machines, the only way to win the maximum jackpot is to play the maximum number of coins (usually three, sometimes four or even five coins per spin). With video machines, the fixed payout values are multiplied by the number of coins per line that is being bet. In other words: on a reel machine, the odds are more favorable if the gambler plays with the maximum number of coins available. However, depending on the structure of the game and its bonus features, some video slots may still include features that improve chances at payouts by making increased wagers.

"Multi-way" games eschew fixed paylines in favor of allowing symbols to pay anywhere, as long as there is at least one in at least three consecutive reels from left to right. Multi-way games may be configured to allow players to bet by-reel: for example, on a game with a 3x5 pattern (often referred to as a 243-way game), playing one reel allows all three symbols in the first reel to potentially pay, but only the center row pays on the remaining reels (often designated by darkening the unused portions of the reels). Other multi-way games use a 4x5 or 5x5 pattern, where there are up to five symbols in each reel, allowing for up to 1,024 and 3,125 ways to win respectively. The Australian manufacturer Aristocrat Leisure brands games featuring this system as "Reel Power", "Xtra Reel Power" and "Super Reel Power" respectively. A variation involves patterns where symbols pay adjacent to one another. Most of these games have a hexagonal reel formation, and much like multi-way games, any patterns not played are darkened out of use.

Denominations can range from 1 cent ("penny slots") all the way up to $100.00 or more per credit. The latter are typically known as "high limit" machines, and machines configured to allow for such wagers are often located in dedicated areas (which may have a separate team of attendants to cater to the needs of those who play there). The machine automatically calculates the number of credits the player receives in exchange for the cash inserted. Newer machines often allow players to choose from a selection of denominations on a splash screen or menu.

Terminology

A bonus is a special feature of the particular game theme, which is activated when certain symbols appear in a winning combination. Bonuses and the number of bonus features vary depending upon the game. Some bonus rounds are a special session of free spins (the number of which is often based on the winning combination that triggers the bonus), often with a different or modified set of winning combinations as the main game and/or other multipliers or increased frequencies of symbols, or a "hold and re-spin" mechanic in which specific symbols (usually marked with values of credits or other prizes) are collected and locked in place over a finite number of spins. In other bonus rounds, the player is presented with several items on a screen from which to choose. As the player chooses items, a number of credits is revealed and awarded. Some bonuses use a mechanical device, such as a spinning wheel, that works in conjunction with the bonus to display the amount won.

A candle is a light on top of the slot machine. It flashes to alert the operator that change is needed, hand pay is requested or a potential problem with the machine. It can be lit by the player by pressing the "service" or "help" button.

Carousel refers to a grouping of slot machines, usually in a circle or oval formation.

A coin hopper is a container where the coins that are immediately available for payouts are held. The hopper is a mechanical device that rotates coins into the coin tray when a player collects credits/coins (by pressing a "Cash Out" button). When a certain preset coin capacity is reached, a coin diverter automatically redirects, or "drops", excess coins into a "drop bucket" or "drop box". (Unused coin hoppers can still be found even on games that exclusively employ Ticket-In, Ticket-Out technology, as a vestige.)

The credit meter is a display of the amount of money or number of credits on the machine. On mechanical slot machines, this is usually a seven-segment display, but video slot machines typically use stylized text that suits the game's theme and user interface.

The drop bucket or drop box is a container located in a slot machine's base where excess coins are diverted from the hopper. Typically, a drop bucket is used for low-denomination slot machines and a drop box is used for high-denomination slot machines. A drop box contains a hinged lid with one or more locks whereas a drop bucket does not contain a lid. The contents of drop buckets and drop boxes are collected and counted by the casino on a scheduled basis.

EGM is short for "Electronic Gaming Machine".

Free spins are a common form of bonus, where a series of spins are automatically played at no charge at the player's current wager. Free spins are usually triggered via a scatter of at least three designated symbols (with the number of spins dependent on the number of symbols that land). Some games allow the free spins bonus to "retrigger", which adds additional spins on top of those already awarded. There is no theoretical limit to the number of free spins obtainable. Some games may have other features that can also trigger over the course of free spins.

A hand pay refers to a payout made by an attendant or at an exchange point ("cage"), rather than by the slot machine itself. A hand pay occurs when the amount of the payout exceeds the maximum amount that was preset by the slot machine's operator. Usually, the maximum amount is set at the level where the operator must begin to deduct taxes. A hand pay could also be necessary as a result of a short pay.

Hopper fill slip is a document used to record the replenishment of the coin in the coin hopper after it becomes depleted as a result of making payouts to players. The slip indicates the amount of coin placed into the hoppers, as well as the signatures of the employees involved in the transaction, the slot machine number and the location and the date.

MEAL book (''M''achine ''e''ntry ''a''uthorization ''l''og) is a log of the employee's entries into the machine.

Low-level or slant-top slot machines include a stool so the player may sit down. Stand-up or upright slot machines are played while standing.

Optimal play is a payback percentage based on a gambler using the optimal strategy in a skill-based slot machine game.

Payline is a line that crosses through one symbol on each reel, along which a winning combination is evaluated. Classic spinning reel machines usually have up to nine paylines, while video slot machines may have as many as one hundred. Paylines could be of various shapes (horizontal, vertical, oblique, triangular, zigzag, etc.)

Persistent state refers to passive features on some slot machines, some of which able to trigger bonus payouts or other special features if certain conditions are met over time by players on that machine.

Roll-up is the process of dramatizing a win by playing sounds while the meters count up to the amount that has been won.

Short pay refers to a partial payout made by a slot machine, which is less than the amount due to the player. This occurs if the coin hopper has been depleted as a result of making earlier payouts to players. The remaining amount due to the player is either paid as a hand pay or an attendant will come and refill the machine.

A scatter is a pay combination based on occurrences of a designated symbol landing anywhere on the reels, rather than falling in sequence on the same payline. A scatter pay usually requires a minimum of three symbols to land, and the machine may offer increased prizes or jackpots depending on the number that land. Scatters are frequently used to trigger bonus games, such as free spins (with the number of spins multiplying based on the number of scatter symbols that land). The scatter symbol usually cannot be matched using wilds, and some games may require the scatter symbols to appear on consecutive reels in order to pay. On some multiway games, scatter symbols still pay in unused areas.

Taste is a reference to the small amount often paid out to keep a player seated and continuously betting. Only rarely will machines fail to pay even the minimum out over the course of several pulls.

Tilt is a term derived from electromechanical slot machines' " tilt switches", which would make or break a circuit when they were tilted or otherwise tampered with that triggered an alarm. While modern machines no longer have tilt switches, any kind of technical fault (door switch in the wrong state, reel motor failure, out of paper, etc.) is still called a "tilt".

A theoretical hold worksheet is a document provided by the manufacturer for every slot machine that indicates the theoretical percentage the machine should hold based on the amount paid in. The worksheet also indicates the reel strip settings, number of coins that may be played, the payout schedule, the number of reels and other information descriptive of the particular type of slot machine.

Volatility or variance refers to the measure of risk associated with playing a slot machine. A low-volatility slot machine has regular but smaller wins, while a high-variance slot machine has fewer but bigger wins.

Weight count is an American term referring to the total value of coins or tokens removed from a slot machine's drop bucket or drop box for counting by the casino's hard count team through the use of a weigh scale.

Wild symbols substitute for most other symbols in the game (similarly to a joker card), usually excluding scatter and jackpot symbols (or offering a lower prize on non-natural combinations that include wilds). How jokers behave are dependent on the specific game and whether the player is in a bonus or free games mode. Sometimes wild symbols may only appear on certain reels, or have a chance to "stack" across the entire reel.

Pay table

Each machine has a table that lists the number of credits the player will receive if the symbols listed on the pay table line up on the pay line of the machine. Some symbols are wild and can represent many, or all, of the other symbols to complete a winning line. Especially on older machines, the pay table is listed on the face of the machine, usually above and below the area containing the wheels. On video slot machines, they are usually contained within a help menu, along with information on other features.

Technology

Reels

Historically, all slot machines used revolving mechanical reels to display and determine results. Although the original slot machine used five reels, simpler, and therefore more reliable, three reel machines quickly became the standard.

A problem with three reel machines is that the number of combinations is only cubic – the original slot machine with three physical reels and 10 symbols on each reel had only 10³ = 1,000 possible combinations. This limited the manufacturer's ability to offer large jackpots since even the rarest event had a likelihood of 0.1%. The maximum theoretical payout, assuming 100% return to player would be 1000 times the bet, but that would leave no room for other pays, making the machine very high risk, and also quite boring.

Although the number of symbols eventually increased to about 22, allowing 10,648 combinations, this still limited jackpot sizes as well as the number of possible outcomes.

In the 1980s, however, slot machine manufacturers incorporated electronics into their products and programmed them to weight particular symbols. Thus the odds of losing symbols appearing on the payline became disproportionate to their actual frequenc