Implementation of the RNG (Random Number Generator)

The Random Number Generator is the invisible heart of every video poker machine, determining the fairness and unpredictability of each hand. Understanding its evolution reveals both the technical challenges and the regulatory battles that shaped modern gaming.

The Early Days: Clock-Based Counters

The first video poker machines used primitive clock-based counters to generate "random" numbers. These systems cycled through a sequence of numbers continuously, selecting whatever number appeared when the player pressed "Deal."

The Timing Attack Vulnerability

Skilled players discovered that these early systems were predictable. By studying the machine's timing and learning its cycle patterns, they could time their button presses to influence the deal. This vulnerability threatened the integrity of the entire video poker concept.

The Continuous Shuffle Revolution

To combat timing attacks, engineers developed continuous background shuffling algorithms. These systems:

Cycle through millions of sequences per second

Never pause or wait for player input

Generate numbers independently of any external timing

The moment you press "Deal," the algorithm captures whatever random state exists at that microsecond. Since the cycle moves far faster than human reaction time, prediction becomes impossible.

The American Coin Scandal (1989)

The American Coin Scandal of 1989 became a watershed moment in RNG regulation. A Las Vegas slot route operator was caught rigging over 1,000 machines by altering the EPROM firmware to prevent Royal Flushes when players wagered maximum coins.

This exploitation of the RNG system had catastrophic implications:

It specifically targeted serious players who bet max coins

It violated the fundamental premise of fair gaming

It exposed the limitations of physical inspections

Nevada Regulation 14: The Fair Deal Standard

The scandal's exposure by the Nevada Gaming Control Board led to Nevada Regulation 14, which mandated:

Video poker RNGs must simulate a standard 52-card deck

No replacement or secondary decision logic is permitted

Each deal must be independent of previous hands

Digital signature verification (checksums) for gaming chips

This regulation established the "Fair Deal" standard, distinguishing video poker legally and technically from slot machines, which have no such transparency requirements.

Modern RNG Architecture

Pseudorandom Number Generators (PRNGs)

Today's video poker machines use sophisticated PRNGs (Pseudorandom Number Generators):

Algorithms like Mersenne Twister generate sequences

Seeds derived from multiple entropy sources

Continuous cycling ensures unpredictability

Statistical tests verify randomness distribution

Hardware vs. Software Debate

The industry has grappled with whether randomness should come from hardware (physical processes like electrical noise) or software (mathematical algorithms):

ApproachAdvantagesDisadvantagesHardware RNGTrue randomnessMore expensive, potential failureSoftware PRNGConsistent, testableDeterministic if seed known

Most modern machines use hybrid approaches, seeding software PRNGs with hardware-generated entropy.

The Role of Independent Testing Labs

Organizations like GLI (Gaming Laboratories International) now certify RNG implementations:

Source code review

Statistical randomness testing

Verification of regulatory compliance

Ongoing audit procedures

The strict sealing of logic boards ensures that the software running on casino floors matches exactly what regulators approved.

Implications for Players

Understanding RNG implementation leads to important conclusions:

Each hand is truly independent—previous results don't influence future deals

The Gambler's Fallacy is a fallacy—machines don't "run hot" or "turn cold"

Timing your button press is futile—the RNG cycles too fast to exploit

Regulated machines are fair—within the constraints of their paytables

The RNG may be invisible, but it's the foundation upon which all video poker strategy rests.