A casino is a shop. The studios are the shelves.

Novomatic has built gaming machines in Austria since 1980, and Greentube is the subsidiary that carried its catalogue online. That catalogue — the "Gaminator" canon — includes Book of Ra, one of the most recognisable slot franchises in Europe, along with Lucky Lady's Charm and Sizzling Hot. The games favour clear, old-school mechanics over cinematic gimmicks, which is precisely their appeal to players who grew up with the cabinets.

On our shortlist this matters for one operator above all: Admiral Casino is Greentube's own UK site (licensed to Greentube Alderney Limited), and it stocks essentially nothing but the house catalogue. Narrow on purpose — and the official way to play these titles online in Britain.

Skill On Net is less a studio than an engine room: it supplies the account system, the lobby and an aggregated wall of third-party games to a family of brands that includes PlayOJO — and, from our list, both Mega Casino and Euromania under UKGC account 39326. It also develops slots of its own, so its casinos mix household names with in-house titles you won't meet elsewhere.

The practical consequence: Mega Casino and Euromania are siblings. Same engine, overlapping catalogues, different shop fronts — which is why our head-to-head between them comes down to presentation and track record rather than the games themselves.

When you sit at a live blackjack or roulette table on a UK-licensed casino, the odds are high that Evolution is running the studio floor. The Swedish company effectively defined the live-dealer format, then spent the last decade buying up slot makers — NetEnt in 2020, Red Tiger before it in 2019, and Big Time Gaming, inventor of the Megaways mechanic, in 2021. Its game shows, Crazy Time chief among them, blurred the line between table game and television.

Among our six, the live rooms at multi-provider operators such as Midnite lean on exactly this ecosystem — one reason a "small" casino can still offer a first-class live floor.

Two names appear in more UK lobbies than almost any other. Pragmatic Play, founded in 2015, releases new slots at a pace nobody else matches and built franchise recognition fast — Gates of Olympus and the Big Bass series are its calling cards, and it runs a live-casino division too. Play'n GO, a Swedish studio with roots back to 1997, wrote the modern template for the "book" slot with Book of Dead and has a deep back-catalogue of mobile-first titles.

Neither ties itself to one operator, which is the point: their presence is close to a baseline expectation in a multi-provider lobby, and their absence is a genuine signal about how a casino sources its games.