Slot machine
A slot machine, fruit machine (British English), poker machine or pokies (Australian English and New Zealand English) is a gambling machine that creates a game of chance for its customers.
"One-Armed Bandit", "Slot Machine", "Fruit machine", and "Pokies" redirect here. For the Jaga Jazzist album, see One-Armed Bandit (album). For the band, see Slot Machine (band). For other uses, see Fruit machine (disambiguation) and Pokey (disambiguation).
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 However, the mechanical operations of early machines have been superseded by random number generators, and most are now operated using buttons and touchscreens.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, banknote, 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 contribute about 70% of the average U.S. casino's income.[1]
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.
Terms and their sources
The "slot machine" term derives from the slots on the machine for inserting and retrieving coins.[2] "Fruit machine" comes from the traditional fruit images on the spinning reels such as lemons and cherries.[3] Slot machines are also known pejoratively as "one-armed bandits", alluding to the large mechanical levers affixed to the sides of early mechanical machines, and to the games' ability to empty players' pockets and wallets as thieves would.[4]
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,[20] 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 frequency on the physical reel. A symbol would only appear once on the reel displayed to the player, but could, in fact, occupy several stops on the multiple reel.
In 1984, Inge Telnaes received a patent for a device titled, "Electronic Gaming Device Utilizing a Random Number Generator for Selecting the Reel Stop Positions" (US Patent 4448419),[21] which states: "It is important to make a machine that is perceived to present greater chances of payoff than it actually has within the legal limitations that games of chance must operate."[22] The patent was later bought by International Game Technology and has since expired.
A virtual reel that has 256 virtual stops per reel would allow up to 2563 = 16,777,216 final positions. The manufacturer could choose to offer a $1 million jackpot on a $1 bet, confident that it will only happen, over the long term, once every 16.8 million plays.
Computerization
With microprocessors now ubiquitous, the computers inside modern slot machines allow manufacturers to assign a different probability to every symbol on every reel. To the player, it might appear that a winning symbol was "so close", whereas in fact the probability is much lower.
In the 1980s in the U.K., machines embodying microprocessors became common. These used a number of features to ensure the payout was controlled within the limits of the gambling legislation. As a coin was inserted into the machine, it could go either directly into the cashbox for the benefit of the owner or into a channel that formed the payout reservoir, with the microprocessor monitoring the number of coins in this channel. The drums themselves were driven by stepper motors, controlled by the processor and with proximity sensors monitoring the position of the drums. A "look-up table" within the software allows the processor to know what symbols were being displayed on the drums to the gambler. This allowed the system to control the level of payout by stopping the drums at positions it had determined. If the payout channel had filled up, the payout became more generous; if nearly empty, the payout became less so (thus giving good control of the odds).
Video slot machines
Video slot machines do not use mechanical reels, but use graphical reels on a computerized display. As there are no mechanical constraints on the design of video slot machines, games often use at least five reels, and may also use non-standard layouts. This greatly expands the number of possibilities: a machine can have 50 or more symbols on a reel, giving odds as high as 300 million to 1 against – enough for even the largest jackpot. As there are so many combinations possible with five reels, manufacturers do not need to weight the payout symbols (although some may still do so). Instead, higher paying symbols will typically appear only once or twice on each reel, while more common symbols earning a more frequent payout will appear many times. Video slot machines usually make more extensive use of multimedia, and can feature more elaborate minigames as bonuses. Modern cabinets typically use flat-panel displays, but cabinets using larger curved screens (which can provide a more immersive experience for the player) are not uncommon.[23]
Video slot machines typically encourage the player to play multiple "lines": rather than simply taking the middle of the three symbols displayed on each reel, a line could go from top left to the bottom right or any other pattern specified by the manufacturer. As each symbol is equally likely, there is no difficulty for the manufacturer in allowing the player to take as many of the possible lines on offer as desired – the long-term return to the player will be the same. The difference for the player is that the more lines they play, the more likely they are to get paid on a given spin (because they are betting more).
To avoid seeming as if the player's money is simply ebbing away (whereas a payout of 100 credits on a single-line machine would be 100 bets and the player would feel they had made a substantial win, on a 20-line machine, it would only be five bets and not seem as significant), manufacturers commonly offer bonus games, which can return many times their bet. The player is encouraged to keep playing to reach the bonus: even if they are losing, the bonus game could allow them to win back their losses.
Legislation
United States
In the United States, the public and private availability of slot machines is highly regulated by state governments. Many states have established gaming control boards to regulate the possession and use of slot machines and other form of gaming.
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 hotel casinos operated in Atlantic City. Several states (Indiana, Louisiana and Missouri) allow slot machines (as well as any casino-style gambling) only on licensed riverboats or permanently anchored barges. Since Hurricane Katrina, Mississippi has removed the requirement that casinos on the Gulf Coast operate on barges and now allows them on land along the shoreline. Delaware allows slot machines at three horse tracks; they are regulated by the state lottery commission. In Wisconsin, bars and taverns are allowed to have up to five machines. These machines usually allow a player to either take a payout, or gamble it on a double-or-nothing "side game".
The territory of Puerto Rico places significant restrictions on slot machine ownership, but the law is widely flouted and slot machines are common in bars and coffeeshops.[31]
In regards to tribal casinos located on Native American reservations, slot machines played against the house and operating independently from a centralized computer system are classified as "Class III" gaming by the Indian Gaming Regulatory Act (IGRA), and sometimes promoted as "Vegas-style" slot machines.[32] In order to offer Class III gaming, tribes must enter into a compact (agreement) with the state that is approved by the Department of the Interior, which may contain restrictions on the types and quantity of such games. As a workaround, some casinos may operate slot machines as "Class II" games—a category that includes games where players play exclusively against at least one other opponent and not the house, such as bingo or any related games (such as pull-tabs). In these cases, the reels are an entertainment display with a pre-determined outcome based on a centralized game played against other players. Under the IGRA, Class II games are regulated by individual tribes and the National Indian Gaming Commission, and do not require any additional approval if the state already permits tribal gaming.[33][34]
Some historical race wagering terminals operate in a similar manner, with the machines using slots as an entertainment display for outcomes paid using the parimutuel betting system, based on results of randomly-selected, previously-held horse races (with the player able to view selected details about the race and adjust their picks before playing the credit, or otherwise use an auto-bet system).[35]