How to succeed in slot machines

History of Slot Machines

The Mechanical Era

The journey of slot machines began in the late 19th century. The earliest precursor to modern slot machines was developed by Sittman and Pitt in Brooklyn, New York, in 1891. This machine featured five drums holding a total of 50 card faces and was based on poker. However, it lacked a direct payout mechanism, leading to rewards like free drinks or cigars for high hands. The need for a simpler machine led to the invention of the Liberty Bell slot machine by Charles Fey between 1887 and 1895. This machine featured an automatic payout mechanism, three spinning reels, and five symbols, greatly simplifying the complexity of reading wins and making automatic payouts feasible​​​​.

The Rise of Electronic Slots

The transition to electronic slot machines began in 1963 with Bally’s development of the “Money Honey,” the first electromechanical slot machine. This innovation enabled automatic payouts of up to 500 coins without an attendant and marked the beginning of the transition towards the electronic games that dominate casinos today. The development of video slot machines further revolutionized the industry. The first video slot was introduced by the Fortune Coin Co. in 1976 in Kearny Mesa, California. This machine featured a modified 19-inch Sony Trinitron color receiver for the display and logic boards for all slot machine functions, leading to its popularity in the Las Vegas Strip and downtown casinos​​.

The Digital Age

The evolution of slot machines continued into the digital age, with the introduction of online slots and the incorporation of advanced bonus rounds, varied video graphics, and themes ranging from popular media franchises to classic symbols. The introduction of the “second screen” bonus round in video slots in 1996 by WMS Industries further diversified the gameplay experience, allowing for different games that could offer additional payouts. Today, slot machines are a staple of both land-based and online casinos, offering players a wide range of betting options and themes​​​​.

Understanding RNGs: True RNGs vs PRNGs

True Random Number Generators (TRNGs)

TRNGs generate numbers based on unpredictable physical processes, making each number truly random. These processes can range from radioactive decay to atmospheric noise, and even quantum phenomena where subatomic particles exhibit random behavior. TRNGs are integral in high-security applications requiring genuine randomness, such as cryptographic key generation. High-end microcontrollers often incorporate TRNG sources, and examples of silicon-based TRNGs include Intel RDRAND​​.

Pseudo-Random Number Generators (PRNGs)

PRNGs, on the other hand, use deterministic algorithms to produce a sequence of numbers that only appear random. They rely on a starting point, or “seed,” and a mathematical formula to generate these sequences. This means if you know the seed and the algorithm, you can predict the sequence, which makes them less secure for cryptographic purposes. Common PRNGs, like the Mersenne Twister, are known for their speed and are widely used in non-secure applications such as simulations and procedural content generation​​.

Cryptographically Secure PRNGs (CSPRNGs)

For applications where security is paramount, CSPRNGs are used. These are a subset of PRNGs designed to be indistinguishable from TRNGs, ensuring that their output is unpredictable and unbiased. The cryptographic strength of a CSPRNG is measured by its ability to withstand being distinguished from a TRNG, even by adversaries with significant computational resources. For example, a game where participants guess the origin of a sequence (TRNG or PRNG) demonstrates that if the guessing rate doesn’t significantly exceed 50%, the PRNG can be considered secure. CSPRNGs must also be resilient to “seed recovery” attacks, where an adversary attempts to determine the initial seed to predict future outputs​​.

In conclusion, while TRNGs are ideal for applications requiring genuine randomness, PRNGs are sufficient for less security-intensive applications. CSPRNGs bridge the gap by offering a balance of performance and security, making them suitable for cryptographic applications where the predictability of standard PRNGs would pose a significant security risk.

Famous Slot Machine Exploits and Frauds

Early Exploits

The history of slot machine exploits begins with simple tricks like the coin-on-a-string method, also known as the “Yo-Yo.” Players would tie a string to a coin, insert it into the slot to register a game, and then pull it back out to reuse. Another early method involved using slugs or coins from other countries that resembled the required coins for the slot machines but were of lesser value.

Hardware Manipulations

Various hardware manipulations have been used to cheat slot machines. Notable methods include:

• Fake Coins or Tokens: Cheaters used manufactured coins that the slot machines recognized as valid.
• Coins on a String (Yo-Yo): A coin attached to a string was inserted and then pulled out after credit was registered.
• Shaved Coins: Cheaters used coins that were shaved around the edges so that the slot machine would accept them for play but then eject them, allowing reuse.
• Coat Hangers: Used to interfere with the mechanical payout sensors to force the machine to release more coins.
• Top-Bottom Joint: A device made from a metal rod and a wire used to create an electrical circuit that tricked the slot machine into paying out.
• Monkey Paw: Invented by Tommy Glenn Carmichael, this device was inserted into the slot machine to trip the payout switch.
• Light Wand: Another Carmichael invention, it was used to blind the optical sensor on slot machines to prevent it from counting the number of coins dispensed.

Software Glitches and Algorithm Manipulation

Some fraudsters have exploited software glitches or manipulated the slot machine’s algorithm to predict the outcomes:

• PRNG Cracking: Cheaters, like the famous case of Alex from Russia, reverse-engineered the PRNG algorithms of slot machines to predict the outcomes of spins.
• Chip Replacement: Dennis Nikrasch changed the software chips of slot machines to manipulate the payout.

The Evolution of Cheating and Countermeasures

The continuous arms race between slot machine developers and cheaters has led to increased security measures, including more sophisticated PRNG algorithms and better hardware security. Many of the old tricks are no longer effective due to these advancements in technology.

Slot machine frauds and the methods used to execute them highlight the constant battle between casino security and fraudsters. The transition from mechanical to digital technology in slot machines has closed many loopholes, leading to more sophisticated and less detectable methods of fraud.

How PRNGs Work in Slot Machines

Slot machines, both physical and online, use complex algorithms and mathematical formulas to determine the outcomes of each spin, known as Pseudo-Random Number Generators (PRNGs). These systems ensure that the results are non-predictable and give the illusion of true randomness, essential for fair and exciting gameplay.

The Role of Seeds in PRNGs

The process starts with a “seed” or a base value, which is an initial number used by the PRNG algorithm. When you press the spin button on a slot machine, this seed is used in a complex equation to decide the symbols that will appear on the pay lines. Despite the intricate nature of these equations, each seed generates consistent results, which is crucial for debugging errors in the program. PRNGs often use the system clock to generate a seed, ensuring unpredictable outcomes by constantly changing this base value​​​​.

Entropy and Natural Randomness

To achieve genuine randomness, or “entropy,” slot machines incorporate factors that ensure each spin is a fair chance event. In digital slots, “simulated entropy” is used to create random keys for the algorithm. Various sources, including mouse movements and keystrokes, can serve as entropy. This unpredictability is crucial for security, preventing potential exploits. Cryptographic hash functions like SHA-1 or MD6 are utilized by online slots to mimic the unpredictability found in physical slot machine processes​​.

Physical vs. Computational Generation Methods

Historically, slot machines relied on physical mechanisms to randomize outcomes, such as the spinning of reels and the stopping mechanism controlled by gears and levers. Modern online slots, however, use computational methods, specifically PRNGs, to generate random sequences of numbers that translate into the symbols you see on the reels. These algorithms are designed to produce sequences that have no discernible pattern, ensuring each spin’s result is unpredictable and fair​​​​.

Ensuring Fairness and Unpredictability

The fairness and unpredictability of slot machines are guaranteed through rigorous testing of their RNG systems. Regulators and independent labs conduct extensive mathematical and statistical analyses to ensure the RNGs do not exhibit any predictable patterns. The Mersenne Twister model, one of the most commonly used RNGs, undergoes billions of tests to confirm its randomness. Additionally, the Return to Player (RTP) rates are also verified by simulating billions of spins to ensure the advertised payout percentages are accurate​​.