Gambling regulators have long required return-to-player (RTP) percentages to be prominently displayed on slot machines, aiming to empower players with the knowledge to make informed gambling decisions. However, a recent study suggests this approach may be flawed. Despite their intention to promote transparency, prior research has shown that most players misunderstand RTP, often leading to an inflated perception of their chances of winning.
The University of Nottingham’s School of Psychology in the UK conducted a research project to assess the true impact of displaying standard RTP messages on slot machines. Their findings, published in *Science Direct* and titled “Never Tell Me the Odds: Typical Return-to-Player Information Increases Gamblers’ Perceived Chances of Winning,” reveal that these messages may inadvertently mislead players rather than help them.
Understanding RTP
RTP refers to the percentage of all wagered money a slot machine is programmed to pay back to players over time. For example, a slot machine with a 90% RTP is expected to return $90 of every $100 bet, while the remaining $10 serves as the casino’s profit, often referred to as the “house edge.”
However, this percentage is calculated over millions of spins and reflects a long-term average. It does not guarantee a 90% return on any single session, nor does it imply that 90% of players will win — both common misconceptions among gamblers. Slot machines are entirely random, meaning some players may win big quickly, while others could lose their entire stake just as fast. Furthermore, RTP disclosures don’t account for additional factors like volatility (how streaky wins and losses can be), hit frequency, or maximum losses.
A Closer Look at the Study
The Nottingham study tested how different types of information affected players’ perceptions of their chances of winning. Researchers surveyed 6,000 slots players from the UK and US, showing them one of four messages before trying a new slot game:
1. A standard RTP statement (“This game has an average payout of 90%”),
2. One of two “house edge” warnings (“This game keeps 10% of all money bet” or “This game is programmed to cost you 10% of your stake on each bet”),
3. Or no information at all.
Participants were then asked how likely they thought they were to win.
Key Findings
The results were striking. Players exposed to the typical 90% RTP message were more than five times as likely to rate their chances of winning as “high,” compared to those who received no information at all. Conversely, both house edge warnings managed expectations better, though neither performed better than offering no message at all.
Interestingly, the study also identified a troubling trend among individuals who exhibited signs of problem gambling. These players were more likely to overestimate their chances of winning when shown no information, suggesting they might be especially prone to filling in the blanks with false hope.
Implications for Gambling Regulators
The study raises critical questions about the effectiveness of RTP disclosures as a tool for promoting informed gambling behavior. It suggests that rather than educating players, current RTP messages may inadvertently encourage overly optimistic betting patterns. The findings also highlight an urgent need for regulators to rethink how gambling information is presented to ensure it aligns with responsible gaming principles.
As the debate continues, the challenge for regulators lies in finding ways to provide players with accurate, helpful information while also minimizing the risk of promoting unrealistic expectations.