28 October 2026
Return-to-Player percentages are increasingly at the center of U.S. lawmaking and regulation for online slots, as more jurisdictions move to make these theoretical disclosures more prominent and more reliable.
Return-to-Player (RTP) is a theoretical average percentage of money bet that is returned to players over the long term, such as after millions of spins. But it is not a guarantee for short sessions. The Missouri Gaming Commission's proposed 2026 amendment to rule 11 CSR 45-5.193, titled "Statistical Performance of Electronic Gaming Devices (EGDs)", upends the certainty of the claim and throws a spotlight on what RTP really means in practice. The amendment requires PAR sheets to disclose "a prominent display of the True Theoretical Average of Expected Return, and a separate statement of the Minimum and Maximum Theoretical Return."
The commission lists 11 specific points of disclosure, including a Volatility Index, a table of award values, and confidence intervals for 6 potential levels of play: 10,000, 100,000, 1,000,000, 10,000,000, and 100,000,000 games. The shifts into serious statistical territory pose implementation challenges for developers and testers.
The Missouri proposal stands out as aggressively statistical, but it is far from the only recent move on RTP. Proposed 2026 legislation in multiple states is pushing for ever-more visible on-screen RTP disclosure, with specific requirements for font size and live updates. On-screen RTP is currently not universally required, and minimum RTP thresholds are uncommon (New Jersey sets a floor of 83%, for example). But a wave of stricter requirements may now be building.
"There are wide variations on what RTP jurisdictions require," said one gaming law expert. "Some have a mandated floor; most don't. Some treat it like an esoteric certification; others want every machine to flag it. I think mandatory, standardized and prominent on-screen disclosure is the inevitable direction, though 2026 may be a few years early for full implementation."
Online slots and RTP: What it is, and why it matters
Not all slots disclose their RTP at all. For players, knowing this "true theoretical average of expected return" is important; for regulators, it is a game of statistics and audit. In Missouri, it has looked ever more like pure math.
"The Total Bonus calculated above does not reflect the final bonus/payback for the game," Missouri Gaming Commission wrote in the proposed rule. "This figure shall be adjusted, as necessary, based upon any adjustments made in the Bonus Pool Size in order to verify that the game adheres to the Minimum, Median, and Maximum Bonus/Payback."
The technical details aside, the implications of the proposal are straightforward. If the Missouri approach crosses over into federal law or is emulated by other states, operators will need to redesign their mobile-app displays and desktop screen UX. Anything less would expose operators to the risk of user-initiated technological evidence in the case of any possible enforcement or dispute.
Watch for RTP rounds in statehouses next year
The momentum of RTP disclosure requirements, brought to a head by the Missouri proposal, could accelerate in 2026. Corporate counsel with slot gaming in their portfolio should look for upcoming legislation or proposed rulemaking in other states. While some states have a minimum RTP requirement, no U.S. jurisdictions currently require mandatory RTP disclosure in individual slots and most jurisdictions require no statutory disclosure of RTP, instead relying on their Random Number Generator Certification process.
"Currently, RNG certification means that slot RTP for machines within a studio or across a gaming network stays within the bounds of the (usually) published PAR sheet, which the casino and regulators have pre-approved, along with historical evidence," explained one industry expert. "For some jurisdictions, this is good enough. But the trend of pushing the RTP values front and center on screen is definitely growing."
Before a corporate counsel's client designs a system for tagging live RTP values, the attorney needs to vet not only the homepage flash but deep conditions the proposed regulation imposes. Any 'Directive Provisioning Section' or 'Separate Theta Ratio' mandate in the Statute Notes indicates that the reform, if passed, will introduce fundamental and important backend changes to lawful compliance.
Players may get clearer RTP signals, but jurisdiction-by-jurisdiction progress is certain
When testing RTP projections, to see if a particularly lucky 1000 spins or 1 million spins are truly representative of the theoretical average, the commission proposes using "the likelihood that a true game return would fall between the Minimum and Maximum Theoretical Return values" at 95% or more for the chosen pool of hypothetical "game rounds." But achieving that level of confidence may force developers to use a larger display font.
The draft language "True Theoretical Average of Expected Return to Player" and proposed display of the Minimum and Maximum Theoretical Return, and the Volatility Index and separate statement of the Minimum and Maximum Theoretical Return seem to crystallize what RTP disclosure, if mandatory, might look like. Nonetheless, industry experts warn that even if the law as constructed tightens disclosure requirements, state-to-state (and U.S. to Canada) variance will result in inconsistent experiences for slot players.
In the end, details matter, but so does the bigger picture. The "true" figure that a more statistically responsible RTP calculation might generate may differ from the adjustment-posted certificate/video-glance value that regulators require. And standards may vary by continent. But the overall momentum toward clearer disclosure of slot payout probabilities is clear. "What's happening in Missouri honestly, is to a degree, happening across gaming activation in the Western market," one gaming policy veteran suggested. "There's a groundswell you can't miss."