Thunderstruck II is one of the slots that shaped online gaming in the UK. Released by Microgaming in 2010, it takes players to Asgard, the home of the Norse gods, and offers a bonus system that rewards you for coming back. Four gods, Valkyrie, Loki, Odin and Thor, each have their own free spins feature, which you unlock over time in the Great Hall of Spins. In this Thunderstruck II slot review we explain how the game works, what each bonus offers and why it is still so popular.
Thunderstruck II at a Glance
| Feature | Details |
|---|---|
| Provider | Microgaming, now part of Games Global |
| Release | 2010 |
| Reels and rows | 5 reels, 3 rows |
| Ways to win | 243 |
| RTP | 96.65% (casinos may use a lower setting) |
| Volatility | Medium |
| Maximum win | 8,000x your stake |
| Stake in the UK | From £0.30 up to the £5 per spin limit (£2 for players aged 18 to 24) |
A Journey to Asgard
Thunderstruck II follows the original Thunderstruck, but with far more depth. The reels are filled with Norse gods and symbols: Valkyrie, Loki, Odin and Thor are the high-value symbols, alongside Valhalla, Thor’s longship and Asgard itself. The low-value symbols are card ranks. A thunderous soundtrack and animated gods give the game a cinematic feel that still holds up today.
How to Play Thunderstruck II
The slot uses 243 ways to win. Matching symbols on adjacent reels, starting from the leftmost reel, form a win. There are no paylines to choose; you only set your stake per spin.
The Thunderstruck II logo is the Wild. It substitutes for all regular symbols and doubles every win it helps to create. Thor’s hammer is the Bonus symbol: three or more anywhere on the reels take you to the Great Hall of Spins.
Wildstorm
Wildstorm is a random feature that can strike on any base game spin. Lightning hits the reels and turns up to five of them completely wild. When all five reels go wild, the result is the biggest base game win possible. Like Wild Desire in Immortal Romance, it is rare, but it adds excitement to every spin.
The Great Hall of Spins
Every time you trigger the bonus, you enter the Great Hall of Spins. At first only Valkyrie’s feature is available. The other gods unlock as you trigger the bonus more often:
| God | Unlocks | Free spins | Feature |
|---|---|---|---|
| Valkyrie | From the first trigger | 10 | All wins multiplied by 5x |
| Loki | From the 5th trigger | 15 | Wild Magic turns symbols into wilds on reel 3 |
| Odin | From the 10th trigger | 20 | Wild Ravens add 2x or 3x multipliers, or 6x together |
| Thor | From the 15th trigger | 25 | Rolling Reels with a multiplier that rises with consecutive wins |
Your progress is saved at the casino where you play. Once all four gods are unlocked, you choose your bonus each time you enter the Hall. Thor’s feature, with its Rolling Reels and growing multipliers, is usually seen as the most exciting, while Valkyrie’s 5x multiplier gives the steadiest results.
RTP, Volatility and Maximum Win
The standard RTP of Thunderstruck II is 96.65%, which is above the average for online slots. Some casinos may offer a lower RTP version, so check the game information. The volatility is medium: wins come at a reasonable pace, and the free spins features offer the bigger payouts. The maximum win is 8,000x your stake.
Compared with many modern slots, the maximum win is modest, but the balanced volatility and the long-term goal of unlocking all four gods make the game enjoyable over longer sessions.
Thunderstruck II on Mobile
Thunderstruck II was updated to HTML5 and runs smoothly on iPhone, Android phones and tablets. The symbols and the Great Hall of Spins menu are clear on a smaller screen. For more advice, see our guide to mobile slots in the UK.
Playing Thunderstruck II in the UK
At UK-licensed casinos, Thunderstruck II follows the rules of the UK Gambling Commission. There is no autoplay or turbo spin, every spin lasts at least 2.5 seconds and the maximum stake is £5 per spin for players aged 25 and over (£2 for players aged 18 to 24). The paytable, features and RTP are the same as in other markets.
Thunderstruck II and Its Sister Games
The Great Hall of Spins system was so successful that Microgaming used it again in Immortal Romance, where four vampire characters replace the Norse gods. The Thunderstruck series also grew with newer titles, including versions with Megaways-style mechanics and link-and-win features. If you enjoy variable reels, have a look at our guide to Megaways slots.
Symbols and Payouts
The four gods are the most valuable symbols in the game, with Thor paying the most for five of a kind. Valhalla, the longship and Asgard sit in the middle of the paytable, while the card ranks from 9 to A provide the frequent smaller wins. Because the Wild doubles every win it is part of, a single Wild on the reels can turn an average combination into a much better payout. Thor’s hammer pays a scatter prize when three or more land, on top of starting the bonus.
Who Is Thunderstruck II For?
Thunderstruck II suits players who want a classic slot with depth. The medium volatility makes it more forgiving than many modern games, and the unlockable bonuses give you something to work towards. Players looking for very large maximum wins, or for a quick, simple game, may prefer something else.
Tips for Playing Thunderstruck II
- Stick to one casino: your Great Hall progress is saved per casino.
- Plan your bonus choice: once unlocked, choose Valkyrie for steady wins or Thor for bigger potential.
- Play at a steady stake: medium volatility rewards longer sessions with a consistent stake.
- Check the RTP: look in the game information to confirm the version your casino uses.
- Look out for free spins offers: classic Games Global slots are often included in free spins bonuses. Since January 2026, UK wagering is capped at 10x.
Is Thunderstruck II Worth Playing?
Yes. Thunderstruck II remains one of the best-designed slots of its generation. The combination of 243 ways, Wildstorm and four distinct bonus features gives it lasting appeal, and the above-average RTP is a welcome bonus.
Where to Play Thunderstruck II
Thunderstruck II is available at most UK casinos that offer Games Global slots. Compare the best UK online casinos, browse more titles on our online slots page, and read our guide to gambling with real money before you deposit.
Play responsibly. Set a budget, take breaks and never chase losses. For free and confidential support, visit BeGambleAware.org. 18+ only.
Features
Thunderstruck II FAQ
What is the RTP of Thunderstruck II?
The standard RTP is 96.65%. Some casinos may run a lower version, so check the game information.
How do you unlock Thor in Thunderstruck II?
Thor's free spins feature unlocks from the 15th time you trigger the Great Hall of Spins.
What is the maximum win on Thunderstruck II?
The maximum win is 8,000x your stake.
What is Wildstorm in Thunderstruck II?
Wildstorm is a random base game feature that can turn up to five reels completely wild.
Is Thunderstruck II the same as Immortal Romance?
No, but both games use a similar unlockable bonus system with four free spins features.
