The RNG
Nowadays slot machines are computerized. The odds are programmed. In modern slot machines, the reels and lever are present for historical and entertainment reasons only. It is a Random Number Generator that chooses the reels positions. The machine's software includes a Random Number Generator.
The RNG is constantly generating random numbers at an extremely high rate. When you pres the Play button the result is determined by the most recent random number. The result is different depending on exactly when the game is played. The result changes every fraction of a second.
Some professional gamblers observe that the RNG does not actually generate random numbers. The sequence of numbers is repeated by most of the RNGs. Poor programming determines such behavior. To build pseudo RNGs with very long periods is relatively easy. No computer can complete a single period in the expected lifetime of the universe. Ronald Dale Harris, a former slot machine programmer, had access to the pseudo RNG code and seed values. Equations for specific gambling games like Keno were discovered by him. Thanks to them the fact that the next set of selected numbers would be based on the previous games became known. But the RNG picks numbers even when the machine is not being played. So the numbers can't be exactly found in a sequence.

Percentage Of The Payout
The percentage of winnings paid out of the money that is wagered by players is 82–98 per cent. This is known as the theoretical payout percentage. Jurisdictions serve to control the minimum theoretical payout percentage. Its establishment refers to the sphere of law or regulation. Nearly each casino has its own winning pattern. It contains the information about the amounts they pay and the frequencies of these pay-outs. The winning patterns on slot machines are carefully selected to yield a certain fraction of the money played to the house. The rest of the money is given back to the players.
When a slot machine's software is written its theoretical payout percentage is also set. Physical swap of the software is needed for changing the payout percentage after a slot machine has been placed on the gaming floor. Based on current technology, this is a time-consuming process and as such is done infrequently. In certain jurisdictions the EPROM has a tamper-evident seal. To change it Gaming Control Board officials should be present. Other jurisdictions randomly audit slot machines to ensure that they contain only approved software.
Thanks to the newly developed technology the game, the odds, and the payouts would be able to be changed by the casino's slot manager remotely. The change can be done only after the selected machine has been idle for at least four minutes. After making the change the machine is locked to new players for four minutes, it displays an on-screen message informing potential players that a change is being made.

Machines That Are Linked
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, awarded to a player who gets a specific combination of symbols. The amount paid for the progressive jackpot is usually far higher than any single slot machine could pay on its own.
Multiple machines can be sometimes linked across multiple casinos. In these cases the manufacturer owning these machines is responsible for paying the jackpot.

Near-miss Programming
The reel display of modern slot machines is under computer software's control. That is why it is possible to make the slot machine frequently display combinations that are close to winning combinations.
This practice of showing combinations that are similar to winning combinations more frequently than would occur randomly is called near-miss programming.
There is a related phenomenon which is also called near-miss. The chance of a winning combination appearing on a pay line is controlled by the winning percentages programmed into the slot machine. The combinations above and below the payline are all roughly equally randomly distributed. This means it is much more likely that a winning combination will appear above or below a pay line than on the pay line. Only if abbreviated physical reels are used to display a win pattern based upon the RNG this can occur. Video slot machines have virtual reels and the symbols that appear around the winning line are usually an accurate depiction of how the reels were mathematically modeled.
The Nevada Gaming Commission investigated the issue of a near-miss above or below the pay line. If the near-miss above or below the pay line was not specially programmed it was stated to be legal. The near-miss and any other combination should have the same possibility of occurrence. The machine cannot be specially programmed to show winning combinations more frequently than other combinations above or below the pay line.
In Australia the usage of near-miss programming, where a near miss is inaccurately displayed is also illegal. Due to this, regulators use stop motion cameras to audit manufacturer's practices.

Slots Fraud
Mechanical slot machines and their coin acceptors were sometimes susceptible to cheating devices and other scams.
Modern slot machines are controlled by EPROM computer chips and coin acceptors were changed for bill acceptors. Different advanced anti-cheating and anti-counterfeiting measures have been taken to make it difficult to defraud these machines. Nowadays microwaves are used to defraud slot machines.

As you know there are different types of slot machines. And do you know that there are even types of slot palyers.
The first type is a persistent player.
The players of this type believe that very soon there will be a period when the machine begins to pay. The machine can begin paying in any second.
The player has either seen a person playing a slots game for a while with no payouts or alternatively they have been depositing funds into a slots game and haven’t yet seen any payouts. They believe that at least any payout is due to happen. The rush is that if they leave after depositing so much money in the machine it will erupt and the payouts will be often and large. Makes sense if you have lost 0. 00 and have yet to win. The machine must pay.
Many years ago in the case of the payout players touch the coins to check whether he coins were hot or cold. If the coins where hot then the slot machine had not paid out in a while and to the chaser this was good as the machine was do. The heat of the machines lights, etc would eventually heat the coins.
The second type of slot players is a chaser.
The player have won and being reinforced by the win gains trust in the slot machine. One can feel the atmosphere of comfort and trust between the machine and the player.

Knowing the rules is of great importance when playing any casino game. With slots the rules are very simple: Read the payout chart, insert coins, push button, (or pull handle), insert more coins. If the bells ring and lights flash, open up your pocketbook because you are in the money! Enjoy, but never gamble with more money than you can afford to lose.
Rules for playing Slots
The rules for slots are one of the simplest set of rules for any casino game. In fact it is so because there are no rules at all. All the player has to do is drop coins in the slot and pull the handle or push the spin button. The mission of the game is to match preselected symbols on the pay line, (or paylines, depending on the machine being played, there can be up to 5 pay lines on some machines), to earn credits. Slots machines have different betting limits. They can be as low as 5 cents and as high as 0.
Especially beginners like slots. They don't have to worry about rules and regulations, or being laughed at by the other players for making a bad play, all they have to do is try to hit the jackpot by matching the highest paying symbols on one of the pay lines.

Slot machines are honest because state gaming commissions make sure they are. But there are some manufactures that design the slots in such a way that they can deceive players.
The very first slot machines worked according to the following principle: the wheels spun and then each of them stopped randomly. Modern slot machines differ form the old ones greatly. There is a chip inside of every slot machine, this chip is programmed to select numbers randomly. The selected number determines the symbol which then comes out. The computer code that generates the random numbers is responsible for whether the machine is “loose” or “tight,” so gaming inspectors look at the machine’s code to make sure that a slot machine doesn’t cheat. There is a legal rate according to which the machine has to pay out. Of course it can pay lower, which happen very seldom.
It is next to impossible to say whether the chip is programmed not in a right way because the machine is not supposed to pay out with every spin. Before the machines are installed in casinos they are examined by inspectors. But you must understand that inspectors can’t examine every machine. They examine the brands. If inspectors approve the brand, they can produce machines, and change them. But these changes must cover legal requirements. Using their right to produce slot machines they insert different chips, which makes the machine pay less.
In one of the casinos the chip was programmed in such a way that royal flushes would never come out. Or a chip that shows near misses of a jackpot. The player would never hit a jackpot but keep on playing maximum bets. Don’t keep silent if you come across such slot machine. Be sure that inspectors will examine this very machine and the casino itself to make sure everything is ok. Manufacturers that cheat are fined or they can lose their license.

Have you ever met a man who has managed to cheat slots?
Slot machines pay on a random basis, but what if you could improve the payout a little? Would you do it? Tommy Glenn Carmichael would and did.
A 53-years Tommy all his life tried to invent some kind of devices to cheat the slot machine. He was caught with one, called a top-bottom joint, and sentenced to prison. After the release Tommy began to invent new kinds of devices for cheating slot machines. His next invention was a slider, a guitar wire. He inserted it into the machine, which released coins form the hopper.
Later, as slot machines became computer based, he had to invent a new tool. He fooled a manufacturer into believing he was a customer and showing him the inside of a slot machine. It was enough for Tommy. Carmichael invented what he called a “light wand. ” The wand, built with a camera battery and a bright miniature light, was used to shine into the slot machine and blind a sensor, causing the hopper to pay out coins. Other gamblers liked his invention and he had a lot of customers, which allowed him to earn up to ,000 a day. With all this money he bought expensive cars, houses and what not.
But good thing will end one day. For Carmichael, they ended in front of a slot machine at Circus, where he was caught with the light wand when he tried to run from security. He was fined, but soon came back to the same business. By this time, authorities had tapped his phone and recorded conversations with other cheats who used his device. Three years’ probation and expropriation was the punishment. He has been banned from entering any casino.