Something clicks the first time you realise the same Starburst you played at one casino is pixel-for-pixel identical at another. That's because operators license games from studios the way cinemas license films — the casino picks the programme, but somebody else made the movie. It's why the studio list matters more than a site's advertised game count, and why the scorecards on the homepage name names.
Greentube (Novomatic)
Slots Land-based heritage
The digital division of Austria's Novomatic, which has been building physical gaming machines since 1980. Greentube's catalogue is where you'll find Book of Ra, Lucky Lady's Charm and Sizzling Hot — titles that existed in bookmaker terminals and arcades long before they reached your phone. The games are simpler than modern video slots, and plenty of players prefer that. In this comparison it's the backbone of Admiral Casino, which makes sense: Admiral and Novomatic are part of the same group.
NetEnt
Slots Swedish
The Swedish studio behind Starburst and Gonzo's Quest — two of the most-played slots ever released in the UK, and the pair most often bolted onto free-spins offers. NetEnt games are known for clean maths presentation and smooth mobile performance, which they've had years to refine; the studio was doing browser-based slots before app stores existed. It's been part of Evolution since 2020, and its catalogue anchors the slots at Duelz.
Play'n GO
Slots Mobile-first
Another Swedish name, and arguably the one that took mobile most seriously earliest — its games were designed portrait-first when rivals were still rotating desktop layouts sideways. Book of Dead is its calling card, and if a UK site runs a spins promotion, there's a fair chance that's the attached game. Duelz leans on Play'n GO heavily, and you'll spot the studio's work across most large UK lobbies including Sky Vegas.
Evolution
Live casino Game shows
Live casino in the UK is, to a first approximation, Evolution. The company streams real dealers from studios in Riga, Malta and elsewhere, and supplies the live blackjack and roulette tables at most licensed operators — including Duelz and QuinnBet from this comparison. It also invented the game-show format (Crazy Time, Monopoly Live) that sits between a slot and a table game. When a scorecard here says "Evolution tables", it means the same tables the biggest brands use.
In-house and exclusive studios
Exclusives Brand-specific
The largest operators commission games you can't play anywhere else. Sky Vegas is the clearest example in this five: part of Flutter, it carries exclusive titles built for the Sky brands alongside the usual studio catalogue. Exclusives aren't automatically better — they're the same maths models in different clothes — but they are one honest reason to pick one site over another if a particular game has your loyalty.
One practical tip to take away: game info screens name the studio. Tap the "i" on any slot and you'll see who made it, its RTP, and its volatility. Thirty seconds there tells you more than any banner will. And if you're curious what RTP actually means for your session, that's covered in how online casinos work.
