Microgaming slots

What happened to Microgaming slots?

Microgaming was founded on the Isle of Man in 1994 and became one of the first companies to build software for online casinos. For two decades its name sat on some of the most recognisable slots in Britain. In 2022, Games Global, also based on the Isle of Man, acquired Microgaming’s games portfolio and its distribution business. The games themselves carried on; the company supplying them changed.

That is why you will now find Thunderstruck II or Immortal Romance listed under Games Global at most UK casinos, while a few lobbies still show the Microgaming label out of habit. Both refer to the same games. Our Games Global slots page covers the current business and its partner studios in detail; this page is about the Microgaming catalogue and how its eras differ.

Microgaming slots by era: a timeline

Reading down the table, you can see the catalogue move from in-house games with a handful of lines, through the 243-ways era, to a model where independent partner studios supplied much of the new content through Microgaming’s Quickfire network.

The 9-line classics: Thunderstruck and Break da Bank Again

Early Microgaming hits used very few lines. Thunderstruck and Break da Bank Again both run on nine paylines across five reels and three rows. Fewer lines mean fewer ways to land a win on any spin, so a larger share of spins pay nothing.

The two games show how different that can feel. Thunderstruck is rated medium volatility with a 96.1% RTP, while Break da Bank Again is rated high with 95.43%. On 300 spins at 20p (£60 staked), the average cost is about £2.34 on Thunderstruck and £2.74 on Break da Bank Again, but Break da Bank Again will usually spread those results much more widely, with more empty stretches and occasional bigger wins.

The 243-ways era: Thunderstruck II and Immortal Romance

Microgaming’s most enduring games switched from paylines to 243 ways to win, paying for matching symbols on adjacent reels from left to right in any row position. Thunderstruck II and Immortal Romance are the two best-known examples, and both added tiered free spins features that unlock as you trigger the bonus more times.

Their figures are among the strongest in the classic catalogue: Thunderstruck II at 96.65% RTP with an 8,000× max win, and Immortal Romance at 96.86% with a 12,150× max win, rated medium and medium-high volatility respectively. If you want to understand why ways games feel busier than line games, read paylines vs ways to win.

Best-known Microgaming slots compared

These are the former Microgaming slots for which we hold verified figures. Remember that casinos can run different RTP versions, so check the game’s info screen.

Why the RTP spread matters in pounds

Nearly nine percentage points separate the top and bottom of that table. Here is what the gap means on the same £200 of stakes.

Mega Moolah’s much lower figure reflects the fact that part of every stake feeds its networked progressive jackpots, money that comes back to players only in the rare event of a jackpot win. Whether that trade is worth it is a personal choice; the are jackpot slots worth it page sets out the arguments. The house edge applies to every game in the table, and losses are the likely result over time.

How UK rules changed the Microgaming classics

Many of these games were designed when autoplay and quick-spin settings were standard. The versions now supplied to British casinos follow current rules, so they may feel slower and plainer than you remember.

• Spins run for a minimum of 2.5 seconds, without autoplay, turbo or slam-stop.
• Returns below your stake are not celebrated with sounds or animations.
• Balance and net position on screen at all times.
• Bonus rounds cannot be bought by British players.
• Stake caps of £5 per spin (25 and over) or £2 (18 to 24).

Our history of online slots in the UK explains how and when these rules arrived.

How to find Microgaming slots in a UK lobby today

1. Search by title first, for example Thunderstruck II or Immortal Romance.
2. If you prefer filters, choose Games Global; some casinos still offer a Microgaming filter.
3. Open the info screen and compare the RTP with the figures in the table above.
4. For Mega Moolah, check the jackpot rules and how the jackpot game is triggered.
5. Set a stake and session budget before your first spin.

Where to play Microgaming slots in the UK

Any UKGC-licensed casino that stocks Games Global content should carry at least some of the classics; search by name. Casumo offers new customers aged 18+ 50% up to £100 on a first deposit of £20 or more, with 10x wagering within 7 days and a £5 max bet; Ladbrokes gives up to 500 free spins at 10p over 10 days after £10 of slots play; 10bet matches a first deposit 100% up to £25 with 10x wagering on slots in 3 days. Terms apply.

18+. Gambling should be entertainment that costs money, not a way to make it. Set a deposit limit before you play: how to set limits. Free, confidential help: National Gambling Helpline 0808 8020 133.