Published on February 22, 2026 | 3 min read
A casino does not build the games it offers. Studios do — Betsoft, Play’n GO, Gamomat, Endorphina and dozens of smaller houses — and they licence finished titles to operators, which is why the same game appears on hundreds of sites behaving identically on each.
The process is more rigid than the marketing around it suggests, and its shape explains several things players find puzzling, including why the same game can pay differently in different places.
Mathematics first, art afterwards
A slot starts as a spreadsheet. A designer fixes the reel strips, the paytable, the hit frequency and the volatility, then simulates the model over billions of rounds until the long-run return lands on a target. Only once the model behaves does theme, art and sound get attached — which is why two games that look nothing alike can share a mathematical skeleton, and two that look identical can behave very differently.
The bonus round absorbs most of the development time because it carries most of the variance. A feature that pays too rarely feels broken; one that pays too often has to be funded by a thinner base game, and balancing the two is months of work rather than weeks.
The finished build then goes to an accredited laboratory — GLI, iTech Labs, eCOGRA or BMM among others — which tests the random number generator for statistical randomness and confirms that the game returns its declared percentage across a very large number of simulated rounds. What is certified is a distribution, not an evening.
- Reel strips, paytable, hit frequency and volatility — decided first.
- Simulation over billions of rounds to hit a target return.
- Theme, art and sound attached to a model that already works.
- Independent laboratory certifies the generator and the declared return.
- Distribution to operators, usually through an aggregator platform.
The detail that surprises players
Many studios ship the same title in several return-to-player configurations, and the operator chooses which to run. It is common to find one game offered at 96 % in one market and several points lower in another. The figure in force is stated in the paytable of the game you are actually in, and checking it is the single most useful habit before playing a familiar title on an unfamiliar site.
Two consequences follow. The mathematics of a game belongs to its studio and is identical wherever that configuration runs, so no casino can make a slot looser or tighter. And the studio’s own page, not a casino’s description, is the authoritative place to read a return figure.
Where the format is heading is visible in what studios licence to each other: Big Time Gaming’s Megaways engine, cluster-pays grids, and the bonus-buy button — which several regulated markets, including the Netherlands and the United Kingdom, have restricted or banned because it converts a slow mechanic into an instant one. The psychology those features exploit is covered in slot design psychology, the arithmetic in casino mathematics, and the themes that carry them in mythology slots. What AI actually does in this industry is set out in futuristic gambling trends, and it is not what the marketing implies.
| Stage | Who decides | What is fixed |
|---|---|---|
| Mathematical model | Studio | Return, volatility, hit frequency |
| Art and sound | Studio | Theme and presentation |
| Certification | Accredited laboratory | Generator and declared return |
| Configuration choice | Operator | Which certified version runs |
| Bonus terms | Operator | Wagering, caps, expiry |