Online Scratchcards · Random Number Generators

Are Online Scratchcards Really Random?

In legitimate chance-based online lottery games, the aim is yes: the outcome should come from a tested randomisation process operating under the game's approved probabilities.

But “random” does not mean every prize is equally likely, and it does not conflict with the result becoming fixed at purchase. The random system chooses an outcome; the game rules decide how likely each outcome is allowed to be.

RNGPRIZE MAPPINGINDEPENDENT TESTINGAUDIT TRAIL
A simplified digital instant result
Random value
Game probability map
Prize outcome
Recorded play
Random selection + unequal prize probabilities can both be true.
Quick answer

Online Lottery Instant Games Can Use Random Number Generation to Select a Result

The World Lottery Association's current security standard applies randomness controls to electronic and chance-based digital games. It requires independent testing before deployment, checks that the RNG is used correctly by the game software and testing that conversion of the raw random numbers does not introduce bias.

Ireland gives a player-facing example: each Instant Win Game outcome is randomly determined from all possible outcomes at the moment of purchase. Lotto NZ says the outcome of Instant Kiwi Online is determined at random when the player clicks Buy.

The misconception

Random Does Not Mean the Jackpot Is as Likely as a Small Prize

A lottery game is not a random choice between prizes with equal-sized slices. Its prize structure deliberately gives different outcomes different probabilities.

A €5 result might be designed to occur relatively often while a €50,000 result may have odds of one in hundreds of thousands or one in a million. The role of the randomisation system is to select fairly within those approved probabilities, not to make every prize equally likely.

What an RNG actually does

What Is a Random Number Generator in an Online Scratchcard?

An RNG supplies unpredictable values that the game software can use when determining the outcome of a chance-based play.

1

The RNG Produces a Value

A secure random-number source produces one or more values for the game engine to use.

2

The Game Applies Its Rules

The game software interprets those values according to the approved prize structure and outcome probabilities.

3

A Prize Tier Is Selected

The resulting value falls into an outcome or prize category defined by the game design.

4

The Individual Play Is Recorded

The operator records the result against the purchased play so it can be audited, recovered or paid correctly.

5

The Animation Presents the Outcome

Later tapping, scratching or spinning can reveal the result without being the mechanism that originally selected it.

True vs pseudo random

What Is the Difference Between a PRNG and a True Random Number Generator?

Both can be used in secure lottery technology, but they obtain randomness in different ways.

Pseudo Random Number Generator — PRNG

A PRNG is software-driven and deterministic. It begins with a starting value called a seed and uses an algorithm to generate a sequence that has the statistical properties of randomness.

If the same PRNG were restarted with exactly the same seed and configuration, the same sequence could in principle be reproduced. That is why secure seeding, reseeding and access controls matter.

True Random Number Generator — TRNG

A TRNG obtains entropy from a physical process rather than relying solely on a deterministic mathematical sequence. WLA describes sources based on physical noise and, in some systems, quantum effects.

The resulting physical entropy can be converted into digital random values or used to seed another random-number system.

WLA notes that lottery technology can also use a hybrid approach: a true random source generates a strong seed, which is then fed into a PRNG that produces the larger stream of values needed by the gaming system.
Predetermined does not mean fake

How Can an Online Scratchcard Be Both Random and Predetermined?

The apparent contradiction disappears once you separate the selection moment from the reveal.

The Result Can Be Randomly Selected at Purchase and Fixed Immediately Afterwards

Ireland states that an outcome is randomly determined from all possible outcomes and set at the moment of purchase. Lotto NZ similarly says the system determines the outcome at random when Buy is clicked.

Before purchaseThe individual paid play has not yet completed the outcome-setting transaction.
At purchaseThe approved randomisation process determines the outcome under the game's rules.
After purchaseThe selected result is now predetermined relative to the later animation, scratching and clicking.

Is the online scratchcard result already decided? →

Random numbers become prizes

How Does an RNG Turn a Random Number Into a €5 Win or a Jackpot?

The exact production algorithms are security-sensitive, but the general idea is probability mapping.

A Simple Illustrative Example

Imagine a game engine works with one million possible numbered positions. Those positions could be divided into prize bands that reflect the approved odds. A large block might map to losing outcomes, smaller blocks to common prizes and a tiny block to the top prize.

Large rangenon-winning outcomes
smaller rangecommon prize
tiny rangelarge prize
very tiny rangetop prize

The RNG supplies the unpredictable value. The game design controls how much of the possible range belongs to each prize tier. This example explains the concept only; it is not a claim about the exact implementation of any named lottery.

This is why WLA tests both parts: the random source itself and the transformation of raw random values into game outcomes. A good RNG could still produce an unfair game if the mapping software accidentally introduced bias.
What does “fair” mean?

Does a Fair RNG Mean Every Online Scratchcard Has a 50/50 Chance?

No. Fairness means the system operates according to the published and approved game probabilities, not that winning and losing must be equally likely.

Fair

The Random Source Behaves as Specified

It produces unpredictable values with the required statistical properties.

Fair

The Game Uses Those Values Correctly

Software should not distort the random source in a way that changes the approved probabilities.

Fair

The Prize Odds Match the Game Specification

WLA guidance calls for mass-data testing of each game to check prize-level odds.

Not required

Every Prize Having an Equal Chance

Lottery prize tables intentionally contain common small prizes and extremely rare top prizes.

Independent testing

How Are Online Lottery RNGs Tested Before Players Use Them?

The current WLA standard is unusually specific about what should be checked.

Is the Random Source Statistically Sound?

Independent tests examine whether generated values behave like high-quality random data. WLA mentions recognised statistical methods including NIST SP 800-22, Diehard and chi-squared tests.

Is the Game Using the RNG Correctly?

The testing should check that the application obtains values from the correct RNG source, handles errors safely and does not misuse or substitute the random data.

Does the Prize Mapping Introduce Bias?

The transformation from raw random values to actual game results must be checked so the game logic does not accidentally distort the intended odds.

PRNG security

If a PRNG Is Deterministic, Could Someone Predict the Winners?

That is exactly why the seed and the surrounding system need strong security controls.

A PRNG Sequence Can Be Repeatable, but It Should Not Be Predictable to a Player or Insider

WLA explains that a PRNG's sequence is determined by its seed. Security therefore depends on using a good-quality algorithm, protecting the seed, managing reseeding correctly and preventing attackers from reconstructing future values.

Strong seedThe starting state should be generated and protected so an attacker cannot work backwards from observed outcomes.
Secure reseedingControls govern how and when new entropy or seed material is introduced.
AuditabilityWhere required, authorised systems can preserve enough information to reconstruct a draw for integrity checking without exposing it to ordinary users.
Can RNG testing prove randomness?

Can Anyone Prove With Absolute Certainty That an RNG Is Random?

No finite statistical test can prove philosophical or mathematical randomness with total certainty.

Testing Looks for the Properties Expected From Random Data

WLA explains that certification involves independent statistical analysis of the distribution and randomness of generated values. Tests look for patterns or properties that would be inconsistent with the specification.

Security Testing Has to Go Beyond Statistics

An RNG can produce excellent-looking random numbers and still be vulnerable if an attacker can alter the software, substitute the hardware or manipulate the surrounding game engine. That is why integrity, access control and auditing matter alongside statistical tests.

Random streaks

Can a Fair Online Scratchcard Produce Five or Ten Losses in a Row?

Absolutely. Randomness does not distribute wins at neat intervals for each individual player.

Normal randomness

Losses Can Cluster

A run of losing plays can occur even when every individual play uses the correct odds.

Normal randomness

Wins Can Cluster Too

Players can occasionally win several times close together without the game becoming “hot.”

Not evidence

Your Short Personal History Cannot Audit an RNG

A handful of results is far too small a sample to establish whether the underlying game is statistically performing as designed.

Better evidence

Large-Sample Testing and Published Odds

Fairness checks use large datasets, game certification and audited configuration rather than expecting each player's sequence to look evenly balanced.

Non-depleting games

Does Another Player Winning Change Your Odds?

Not in a non-depleting digital instant model such as the one publicly described by the Irish National Lottery.

Ireland Says Each Play Keeps the Same Stated Odds

Its responsible-play information says the Instant Win Game prize pool is non-depleting, so winning or losing on one play does not affect the odds of later plays.

This Is Different From a Finite Physical Scratchcard Game

A paper game has a fixed population of manufactured tickets, so selling or claiming a specific winning ticket changes which physical prizes remain in circulation. A non-depleting online game does not work through the same finite stock mechanism.

Physical vs online scratchcards →

Can the system target you?

Can an Online Scratchcard Secretly Change Its Odds Based on Your Account?

A legitimate regulated game should run according to its approved game specification rather than quietly changing an individual player's prize odds outside those rules.

The Game Configuration Is Part of What Is Tested

WLA requires the game engine configuration and audit trail to be checked against the approved specification.

Prize-Level Odds Can Be Tested in Mass Data

Large-scale simulated or test results can be compared with the game's specified prize probabilities.

Online Games Need Lifecycle Evidence

WLA says dedicated online games should be tested and supported by evidence demonstrating integrity and correct prize payout throughout their lifecycle.

The important distinction: technically, software can be programmed to do almost anything. The fairness question is whether the production game is independently tested, controlled and monitored so it behaves as its approved rules say it should.
A U.S. example

Do U.S. Lotteries Use RNGs for Digital Lottery Games?

Yes. Virginia's official lottery material provides a straightforward current example of computer-generated lottery outcomes.

Virginia Explicitly Uses Random Number Generators

The Virginia Lottery explains that some computer-based game outcomes are determined by a Random Number Generator, illustrating the same broad electronic-randomness principle used across digital lottery products.

“Uses an RNG” Is Only the Beginning of the Security Story

The generator itself, the game code that consumes its output, the system configuration and the transaction audit trail all matter. A technically random source cannot guarantee a fair game if the surrounding software is implemented incorrectly.

Could an RNG be hacked?

What Stops an Insider or Hacker Manipulating Online Scratchcard Results?

Randomness certification alone does not protect a gaming system from deliberate interference.

WLA Separates Randomness From Security and Integrity

Its guidance identifies risks such as replacing RNG hardware or software, attacking game code, manipulating system time and exploiting weak configuration. The current standard therefore adds access controls, secured transmission, auditability and segregation of duties around electronic gaming systems.

Protected componentsThe RNG, game engine and related systems should be hardened against unauthorised access or alteration.
Independent rolesNo one person should be able to maintain, monitor and operate critical electronic drawing functions without oversight.
Audit evidenceSystem logs, configuration reports and test evidence make suspicious or incorrect behaviour easier to investigate.

How scratchcard security and fraud prevention work →

Common misunderstandings

Six Myths About Random Online Scratchcards

Myth

“Random Means Every Prize Is Equally Likely”

The prize probabilities are deliberately unequal; randomness selects within that approved structure.

Myth

“Predetermined Means It Cannot Be Random”

A random result can be selected at purchase and then become fixed for the later reveal.

Myth

“A Losing Streak Proves the RNG Is Rigged”

Streaks are normal in random processes and a short personal sequence is not a statistical audit.

Myth

“A PRNG Is Automatically Fake Randomness”

PRNGs are deterministic, but well-designed, securely seeded PRNGs can produce statistically strong unpredictable sequences suitable for controlled gaming systems.

Myth

“Testing the RNG Once Is Enough”

WLA requires pre-deployment independent testing and a policy for after-deployment checks and verification.

Reality

The RNG Is Only One Part of Fairness

The game engine, probability mapping, configuration, cybersecurity and audit trail all have to work correctly too.

Frequently asked questions

Online Scratchcard Randomness: 12 Common Questions

Different lottery operators can use different technical architectures, so these answers focus on documented security principles and operator-specific examples rather than assuming every digital instant game uses the same RNG design.

Are online scratchcards really random?

In legitimate chance-based online lottery games, the result should be generated through an approved randomisation process and then mapped into the game's published prize structure. The exact technical method varies, but current WLA standards require independent testing of the RNG and the way its output is used.

How can an online scratchcard be random if the result is predetermined?

The result can be randomly selected at the moment of purchase and then become fixed for that individual play. Random describes how the outcome is chosen; predetermined describes the fact that later animation or clicking does not change it.

What is an RNG?

RNG means random number generator. It produces values that a game engine can use to select an outcome. WLA distinguishes True Random Number Generators, which use a physical entropy source, from Pseudo Random Number Generators, which generate a sequence from a seed.

What is the difference between a PRNG and a true RNG?

A PRNG is deterministic software: the same starting seed can reproduce the same sequence. A true RNG derives entropy from a physical process. WLA notes that lottery systems can also use hybrid approaches where true randomness is used to seed a PRNG.

Does random mean every prize has the same chance?

No. Random selection does not mean equal prize probabilities. A game's rules can deliberately make a small prize much more likely than a jackpot. The important requirement is that the random output is mapped into the approved prize odds without unintended bias.

Can the lottery change the odds for one player?

A properly controlled game should operate according to its approved rules and tested configuration. WLA standards require independent testing, configuration controls, audit trails and checks that the random source and game engine are being used correctly.

Can losing several times in a row prove the RNG is unfair?

No. Random processes naturally produce streaks and clusters. A losing run can feel suspicious without being statistically unusual. Fairness is assessed using the game's published odds, large-sample testing and system controls rather than one player's short sequence.

Does another player's win make my next online scratchcard worse?

Not in non-depleting models such as the Irish National Lottery's Instant Win Games, where the operator says winning or losing on one play does not affect the odds of later plays.

Are RNGs independently tested?

WLA-SCS:2024 requires pre-deployment tests and verification by independent parties and ongoing policies for after-deployment checks. It also calls for mass-data testing of prize-level odds.

What do RNG tests actually check?

Tests can examine statistical randomness, correct use of the RNG by the game, secure seeding and reseeding for PRNGs, fail-safe behaviour, correct transformation of raw random values and whether simulated prize frequencies match the game's specification.

Can an RNG be hacked or manipulated?

Any computerised system can face security threats, which is why randomness testing alone is not enough. WLA separately requires security, integrity, access control, auditability and segregation of duties around electronic gaming systems.

Can a free demo show whether the paid game is random?

No. Demo play is not a reliable test of the paid game's outcome distribution. Official operators can separate free-play mode from paid play, and meaningful fairness testing requires very large datasets and access to the actual production configuration.

Sources and evidence

Where This Information About Online Scratchcard Randomness Comes From

This page relies on current lottery-security standards and official operator explanations of digital instant-game outcomes and odds.

World Lottery Association — WLA-SCS:2024 Code of PracticeCurrent requirements for independent RNG testing, correct use of the random source, bias-free transformation, PRNG seeding and reseeding, mass testing of prize odds, system integrity and online-game certification.Open source →
World Lottery Association — Random Chance Is the Essence of the LotteryDetailed WLA explanation of PRNGs, TRNGs, entropy, hybrid systems, statistical testing, RNG certification and security risks.Open source →
Irish National Lottery — Know the OddsStates that every Instant Win Game outcome is randomly determined from all possible outcomes at the moment of purchase and that its prize pool is non-depleting.Open source →
Irish National Lottery — How Do I Know If I Have Won?Confirms that Instant Win Game outcomes are predetermined at purchase and that player actions do not influence the result.Open source →
Irish National Lottery — Digital Mega Money Multiplier RulesExample of a digital game whose rules publish prize-tier odds and state that the Central Gaming System randomly determines the prize at purchase.Open source →
Lotto NZ — Instant Kiwi Online FAQsOfficial statement that the outcome of an Instant Kiwi Online game is determined at random by the system when the player clicks Buy.Open source →
Virginia Lottery — Frequently Asked QuestionsCurrent U.S. operator material confirming use of Random Number Generator technology for computer-determined lottery outcomes.Open source →
Important context: lottery operators do not normally publish the exact production RNG seeds, outcome-mapping code or live security configuration — nor should they. This page explains the auditable principles used to establish randomness and integrity without pretending to know confidential implementation details.