Slot guide
Thunderstruck slot review: Microgaming's original 9-line Thor game
The original 2004 Thunderstruck from Microgaming: nine lines, a Thor wild and 15 free spins from Ram scatters with every win tripled.
Thunderstruck dates from 2004, when Microgaming released a five-reel, nine-line slot built around Thor. The catalogue now sits with Games Global. The Thunderstruck slot returns 96.10% in theory, is rated medium volatility and has a top win of 3,333x the stake. Its features are few and easy to follow: a Thor wild, Ram scatters that award 15 free spins, tripled wins throughout the round and a gamble option on wins.
Thunderstruck: spec sheet
From the provider's published game sheet.
- Provider
- Microgaming (catalogue now Games Global)
- RTP
- 96.10%
- Volatility
- Medium
- Max win
- 3,333x stake
- Reels
- 5
- Rows
- 3
- Lines
- 9
- Min bet
- €0.09
- Released
- 2004
Features
- Thor wild symbol
- Ram scatters: 3 or more award 15 free spins
- All free spins wins tripled (x3)
- Free spins can be retriggered
- Gamble feature
RTP can be set lower by some casinos; the game's own help screen shows the figure that applies. 18+ only.
Thor, the Rams and the tripled free spins
Thor is the wild and substitutes to complete line wins. The Rams are the scatters: three or more anywhere on the reels award 15 free spins. Every win during free spins is tripled, and the round can be retriggered, which is how the game reaches its upper range. With only nine lines, base game wins tend to be spaced out, so the free spins carry most of the game's value.
The original also offers a gamble feature on wins. It is optional, it can cost the win it puts at stake, and it does not improve the long-run return.
Thunderstruck or Thunderstruck II?
The two are often confused. Thunderstruck II arrived in 2010 with 243 ways to win instead of fixed lines, and it has its own RTP and features. The figures on this page apply only to the 2004 original with nine lines. Thunderstruck II Mega Moolah, Wild Lightning, Stormchaser, Stormblitz and Gold Blitz Extreme are separate games again.
Is the original still offered for real money?
Availability is uncertain. Some casino guides describe the 2004 game as withdrawn from real-money play and kept only as a demo, and Games Global has no public product page for it. Release dates in published listings also differ, and the maximum stake is quoted in two different ways, so it is left off the spec card. If a GB casino lobby lists Thunderstruck, check that it is the nine-line original and read its help screen for the RTP and stake range. The operators beside this page carry Microgaming or Games Global titles, but that does not confirm this specific game.
The Thunderstruck slot under the £5 cap
The minimum bet is listed at €0.09. At the top end, GB rules decide the limit: online slots at GB-licensed casinos are capped at £5 per spin for adults and £2 for players aged 18 to 24. At £5, a 3,333x result would be about £16,665, and that is a ceiling rather than an expectation. The stake limits guide explains the caps.
Is there a Thunderstruck demo?
If the original is now demo-only, as some guides report, a licensed casino's demo mode may be the only place to see it. GB rules require those casinos to verify age and identity before any play, free versions included, and All British Casinos does not host playable games. In demo mode the slow pace of a nine-line game becomes clear quickly, as does the wait between Ram triggers. The free slots page explains demo access, and the RTP guide explains what 96.10% means over time.
18+ only. Set a budget before you start, and use the responsible gambling page for limits and support.
UK-licensed casinos, ranked by our score
Order = score out of 10. Every operator holds a Gambling Commission licence.
| # | Casino | Score | Welcome offer and significant terms | Payments | Links |
|---|---|---|---|---|---|
| Place 1 |  32RedPlatinum Gaming Limited | Score: 7.9 out of 10, good | No welcome offer listed in the terms we read. |
| Visit 32Red (opens the operator site in a new tab)Read the review: 32Red |
| Place 2 |  Magical VegasRank Interactive (Gibraltar) Limited | Score: 8.1 out of 10, very good | 100 bonus spins after a £10 deposit and £10 stake Significant terms Min deposit £10 and £10 stake; Paysafecard excluded; 10x wagering; max win £200; spins on The Goonies Quest for Treasure Jackpot King |
| Visit Magical Vegas (opens the operator site in a new tab)Read the review: Magical Vegas |
| Place 3 |  Wink SlotsBroadway Gaming Ireland DF Limited | Score: 6.8 out of 10, good | 50% games bonus up to £100 on a £10 first deposit Significant terms Min deposit £10; 50% bonus up to £100; 10x bonus wagering; 5-day expiry |
| Visit Wink Slots (opens the operator site in a new tab)Read the review: Wink Slots |
| Place 4 |  Jackpot CityBetway Limited | Score: 5.9 out of 10, fair | No welcome offer listed in the terms we read. |
| Visit Jackpot City (opens the operator site in a new tab)Read the review: Jackpot City |
Ad We may earn a commission if you open an account through links on this page; it does not change our scores or the order of operators. How we score · Advertising disclosure
Questions readers ask
What is the RTP of the original Thunderstruck?
The spec gives 96.10% with medium volatility. Check the game's help screen at the casino, since builds can differ.
How do Thunderstruck free spins work?
Three or more Ram scatters award 15 free spins. All wins in the round are tripled, and the free spins can be retriggered.
What is the difference between Thunderstruck and Thunderstruck II?
The original from 2004 has nine lines and one free spins round. Thunderstruck II from 2010 uses 243 ways to win and a different bonus structure.
Can I still play the original Thunderstruck for real money?
Possibly not. Some casino guides say the 2004 game is now demo only. If a GB lobby lists it, check that it is the nine-line original; stakes there are capped at £5 per spin, or £2 if you are aged 18 to 24.