Can a casino change a game's RTP after it is certified?

Not lawfully on its own. Kenyan rules require game mechanics and platform changes to be approved or notified to the Gambling Regulatory Authority, the declared return to player to be disclosed, and software changes to be re-tested before deployment. A licensed operator that quietly alters a certified game breaks these rules.

By Nairobi Ultimate Editorial (prepared with AI tools under our editorial policy) · Last updated 2026-10-16

The short answer

A certificate describes a game as it was when it was tested. Kenyan regulations are built so that the game on a licensed platform stays that game: changes must be approved, notified or re-tested, and the declared percentage must be disclosed.

That does not mean a change is physically impossible. It means a licensed operator that changes a certified game without going through the process is breaking its licence conditions, and the regulator has powers to act. This guide sets out which rules apply and what a player can and cannot verify.

What RTP is, and what "certified" refers to

Return to player (RTP) is the share of all stakes a game pays back on average over a very large number of rounds. It comes from the game's rules and paytable combined with the probabilities produced by a random number generator. The guide to how RTP and house edge work shows the arithmetic.

Under regulation 45(2) of the Conduct of Gambling Operations Regulations, 2026, the generator used for all games of chance is certified by the Authority or its approved agent to statistically test the randomness and the theoretical return to player. What is certified is therefore a specific version of the generator and the game rules. A different paytable is a different game for certification purposes.

The rules that govern a change

"Operations Regulations" means the Gambling Control (Conduct of Gambling Operations) Regulations, 2026 (L.N. 112). The same set is described from the testing side in the guide to how RNG testing and certification work in Kenya.

What the supplier promises

A software supplier applies for authorization on Form 12 of the Licensing Regulations, 2026. In section C2 the applicant names the independent testing laboratory and commits to "notifying the GRA of any material change to the software and submitting it for re-testing prior to deployment".

In section F1 the applicant also declares that it will not deploy "any significant modification or new game type without prior GRA approval or notification as per the regulations". The order matters: re-testing and approval come before the change goes live, not after.

Why a small change would be hard to notice

A player cannot rely on feel or on a short run of results to spot an altered percentage. The sums below show why.

Illustrative example. Take a made-up game where each round costs a stake of 1 unit. With probability 0.40 it pays 2.4 units back, otherwise it pays nothing.

1. Declared RTP = 0.40 x 2.4 = 0.96, or 96%.
2. If the paytable were quietly changed to pay 2.2 units on a win, RTP = 0.40 x 2.2 = 0.88, or 88%.
3. On 10,000 rounds of KES 100, total stakes are KES 1,000,000. Expected return is KES 960,000 at 96% and KES 880,000 at 88%, a difference of KES 80,000.

Now the noise. In the original game the average payout per round is 0.96. The mean of the squared payout is 0.40 x 2.4 x 2.4 = 2.304. The variance is 2.304 minus 0.96 x 0.96 = 2.304 - 0.9216 = 1.3824, so the standard deviation of one round is the square root of 1.3824, about 1.18 units.

Over 10,000 rounds the standard deviation of the average return is 1.18 divided by the square root of 10,000, which is 1.18 / 100 = 0.0118, about 1.2 percentage points. Over 100 rounds it is 1.18 / 10 = 0.118, about 12 percentage points. A session of 100 rounds can therefore end anywhere from roughly 84% to 108% on the original game, which easily hides a change from 96% to 88%. This is the same variance explained in the guide to what volatility is.

Why the lack of visible evidence is not an excuse for operators

Because players cannot detect small changes, the system does not rely on players. It relies on four things: the certified rules on file, the audit log and monitoring interface in regulation 41, annual evaluation under regulation 45(3), and the supplier's own re-testing commitment. Regulation 92(1)(q) also lists fairness of games and test reports among the records a licensee keeps.

The weak point is not the paper process but who is bound by it. These obligations attach to licence holders. A site with no Kenyan licence has made no such promise to the Authority, and a certificate logo on its page is only an image. The guide to the role of the Gambling Regulatory Authority explains how licensing and enforcement fit together.

What you can check yourself

• Find the declared figure. Open the game's rules or help screen and note the theoretical return to player and the date you looked. Regulations 20(2) and 45(3) say it should be there.
• Keep a screenshot. If the figure later differs from your record, you have something concrete to put to customer care.
• Separate variance from change. A bad session is expected arithmetic. A written figure that has moved is a different matter.
• Check the licence. Look up the company on the regulator's published register. It describes the 2025/26 trading period, so check the live page on the regulator's site.

Gambling is addictive. Play responsibly and only with money you can afford to lose; a certified game still has a built-in cost.