- Fully random machines keep odds constant; previous wins or losses do not change the next result.
- Compensated machines monitor recent payouts against their target return to player and can slightly adjust future odds or prize values.
- Compensation works both ways — a machine can become more generous when below target and pay out less when above target.
- All UK findings are UK-specific; they do not confirm how machines operate in other jurisdictions or for all online slots.
- The size of any compensation adjustment after a jackpot is not quantified in the supplied sources.
On a fully random slot machine, a large jackpot has no effect on the next spin — each outcome is independent. On a compensated machine, past results do influence future odds: if the machine has paid out above its target return to player, the software can slightly reduce win frequency or value for subsequent games until it moves back toward target.
Fully Random Machines: Past Wins Have No Influence
On a fully random machine, the odds of achieving a win in the current game remain constant and are not affected by wins or losses in previous games. These machines use a random number generator and rely purely on statistical chance to meet their target return to player over a very large number of plays, typically in the order of a million or more game cycles.
The target return to player is an average over many plays, not a guarantee for any session. A jackpot win does not make the next spin more or less likely to win. The averaging effect happens only because random outcomes balance out over a very large sample, not because the machine corrects itself after a big win.
Sources: Return to player – how much gaming machines payout; Feature article – How can gaming machines meet their %RTP if they are ….
Compensated Machines: Past Wins Can Influence Future Payouts
Compensated machines are also random and use a random number generator, but they add a feedback control. The software constantly checks how much has been awarded in winnings in the recent past and, knowing the current return to player and the target, will slightly vary the odds of achieving a win or slightly vary the value of any win for the subsequent series of games.
If a machine is below its target return to player it may become more generous dependent upon design, or it may pay out less when it is above target. That means after a large jackpot that pushes the actual return above target, the machine can pay out less often or offer smaller amounts until the return moves back toward target. The opposite is also true after a losing streak.
The reason for using compensation is to give a less volatile game experience and a more even cash flow for operators, and to allow complex multi-option games with many player choices to still meet their target return.
Hypothetical illustrative example: imagine a compensated machine with a 90 percent target that has just paid a large jackpot and is now at 95 percent actual return over its recent window. The software detects it is above target and slightly lowers the chance of a win on the next series of games. This does not predetermine a loss, it only nudges probability. The amount and frequency of prizes is still determined by random chance.
| Feature | Fully Random Machine | Compensated Machine |
|---|---|---|
| Effect of past jackpot | No effect, odds stay constant | Can temporarily lower win chance or value if above target |
| How target return is met | Statistical chance over very large number of cycles | Feedback loop adjusting odds or values over tens or hundreds of thousands of cycles |
| Still uses random number generator | Yes | Yes, with additional control element |
| Goal of design | Pure chance outcomes | Less volatile experience and easier to hit target for complex games |
Sources: Return to player – how much gaming machines payout; Feature article – How can gaming machines meet their %RTP if they are ….
Progressive Jackpots and What the Evidence Does Not Show
For progressive jackpot systems, the supplied sources require operators to explain how the jackpot is funded, its seed and ceiling values, and how contributions are handled, and to notify players of the reset value after a win. They also state that games connected to progressive jackpots should be measured at a base game level separately from the jackpot component, and that jackpot performance should be monitored separately.
The sources do not state that the base game payout rate tightens after a progressive jackpot is won. They do not confirm or deny a post-jackpot adjustment to the base game, and they note that measuring jackpot return to player may not be feasible due to high volatility.
Evidence scope is limited to the UK Gambling Commission. The distinction between compensated and random machines, and the requirement that machines display whether they are compensated or random and their return to player, is described for the UK. The sources do not establish whether the same categories and rules apply in other markets, how widespread compensation is in online slots globally, or how large any compensation adjustment would be in practice after a big win.
Sources: Guidance to licensing authorities – RTS 9 – Progressive jackpot systems; Measuring progressive jackpots – Gambling Commission; Return to player – how much gaming machines payout.
Sources and further reading
- Return to player – how much gaming machines payout
- Feature article – How can gaming machines meet their %RTP if they are …
- Guidance to licensing authorities – RTS 9 – Progressive jackpot systems
- Measuring progressive jackpots – Gambling Commission
Community questions behind this article
These discussions helped identify the question. Player comments are not used as evidence for game rules or odds.
Prepared with AI assistance and automated checks against the cited research brief. Human review is not implied. Source research date: 2026-09-22.
Frequently Asked Questions
Does hitting a jackpot mean the machine is now cold?
Only on a compensated machine could the odds be slightly adjusted when the machine is above its target return. On a fully random machine each spin is independent, so a jackpot does not make the machine cold.
Are online slots always fully random?
The supplied sources do not clearly confirm how widespread compensation is in online slots globally. They note compensation is particularly common in complex physical machines, such as pub-style machines, but do not give a global breakdown for online games.
