Are FOBT Machines Rigged or Fixed? Fairness, Myths & How They Work
Fixed Odds Betting Terminals (FOBTs) are a familiar sight in betting shops across the UK, and they often spark debate about how fair they really are.
Questions about rigging persist, but the answers sit in how these machines are designed, tested and regulated. Once that is clear, many of the myths start to fall away.
This blog post explains how outcomes are generated, what RNGs do, how regulation and independent testing work, what RTP really means, whether staff can interfere, and how to spot and report problems if something seems off.
Read on to learn more.
How Do FOBT Machines Generate Outcomes?
FOBT machines use computer software to determine the result of each game. The system is built so that outcomes do not follow a pattern and cannot be predicted in advance.
Each play is a separate event. The result is calculated at that moment and is not influenced by previous spins, the time of day, or how many people are using the machine. If a player notices what looks like a pattern, that is simply coincidence rather than the machine changing its behaviour.
Put simply, the machine runs a calculation for every play, and that calculation decides the result on the spot. So what actually powers that calculation behind the scenes? That is where the Random Number Generator comes in.
Do FOBT Machines Use Random Number Generators?
Yes. An RNG, or Random Number Generator, is the core piece of software that picks results. It produces an ongoing stream of numbers at high speed, and each number maps to a possible outcome on the game.
Because the RNG is constantly producing numbers, the outcome that is captured when a player presses the button is effectively selected from that live stream. As explained earlier, this keeps each play independent from the last without any built-in sequence.
Access to the RNG is tightly controlled. Shop staff do not have the ability to view or change it, and the software is locked and monitored so it runs as designed.
Who Regulates FOBT Fairness In The UK?
In the UK, the Gambling Commission sets the rules that govern how FOBT machines must operate. These rules cover technical standards for game design, how outcomes are generated, how information is displayed to players, and how returns are measured.
Licensed operators are required to follow these standards and are subject to checks that look at both the machines and how they are managed. This framework is designed to make sure that the games do what they claim to do and that players can see the key information they need.
Regulation sets the bar, but how do we know the machines actually meet it? That is where independent testing comes in.
Independent Testing And Certification Of FOBT Machines
Before a machine reaches a betting shop, it is examined by an independent testing laboratory. These labs are separate from manufacturers and operators, and their job is to test whether a game behaves exactly as its rules state.
Checks typically include:
- Whether the RNG performs within strict statistical ranges
- Whether the advertised RTP is accurate over extended simulations
- Whether the software resists unauthorised changes and logs key events
Only when a machine passes all relevant tests does it receive certification. Testing does not stop at launch. Approved versions are recorded, any software updates must be re-tested and certified, and field audits can confirm that the version in use matches the certified one. Many machines also produce secure logs so investigators can review how they have been used if an issue is raised.
With those safeguards in place, the next question many people ask is what players can reasonably expect back from a game over time. That is where RTP comes in.
What Does RTP Mean For FOBT Games?
RTP stands for Return to Player. It is a long-term average that shows the proportion of total stakes a game is designed to return to players over a very large number of plays. For example, a 95% RTP means that, in theory, £95 is returned for every £100 wagered across all plays over time.
This does not mean an individual session will return 95%. Short-term results can vary widely because outcomes are decided per play. Some games also have features that create larger but less frequent wins, which can make results feel uneven even when the long-term average is accurate.
RTP figures are set by the game designer and are part of the certification process described earlier. They are not predictions for any one person and should be read as a guide to how the game is built rather than a measure of how any session will go.
Can Staff Or Operators Tamper With FOBT Machines?
These machines are built with multiple layers of security to prevent tampering. Cabinets are sealed, access requires specific keys or codes, and opening them creates audit entries. The core software is typically signed so that any change would be detected.
Shop staff look after practical tasks such as cleaning, basic troubleshooting, or replacing printer paper. They do not control the software that decides outcomes, and they cannot change game settings. Technical work is carried out by trained engineers following documented procedures, and operators face serious penalties for breaches.
The idea that a member of staff can flip a switch to alter results is a common worry, but it is not how regulated machines are designed to work. Myths like that persist, so it is worth looking at them directly.
Common Myths About FOBT Rigging
A frequent myth is that machines pay out more during quiet times or hold back when a shop is busy. In reality, the outcome is generated within the machine and does not reference the time, the shop, or the number of nearby players.
Another belief is that a machine is due to pay after a long run without a win. Each play is calculated on its own, as explained earlier, so previous outcomes do not move a machine closer to any particular result.
Some also think staff can secretly adjust the odds. As covered above, staff do not have that kind of access, and any change to certified software would be flagged by the machine’s security and logs.
If a machine is not behaving as you would expect, it is more likely to be a technical fault than a hidden switch. Knowing what to look for can help.
Signs A FOBT May Be Faulty Or Manipulated
Most issues are simple faults rather than anything more serious, but they should still be treated carefully. Clear warning signs include unfamiliar error messages, the screen freezing, buttons not responding, or the machine restarting for no obvious reason.
Payment issues are another red flag. If the machine will not accept money, fails to print a ticket, or the amount paid out does not match what is shown on screen, that warrants attention. Physical problems such as loose panels, broken seals, or visible damage should also be taken seriously.
If any of these problems appear, the safest option is to stop playing and let someone know. Here is how concerns are usually handled.
How To Report Suspected Faults Or Tampering
If you believe a machine is faulty or has been interfered with, stop using it and speak to a member of staff. They can take the machine out of service, record the details, and arrange for technical checks. If you prefer not to raise it in the shop, or the response does not address your concern, you can contact the Gambling Commission, who provide guidance on reporting machine issues.
Clear information helps investigations. Noting the shop location, the time, the machine number or description, and what you saw will make it easier to look into. If you have a photo of an error message or damage, that can be useful too. Genuine reports are welcomed and there is no penalty for raising a concern in good faith.
Play should always remain under your control. If gambling starts to affect your well-being or finances, support is available from organisations such as GamCare and GambleAware, who offer free, confidential help.
**The information provided in this blog is intended for educational purposes and should not be construed as betting advice or a guarantee of success. Always gamble responsibly.
