Thunderstruck II is one of Microgaming’s most popular slots — a Norse-mythology classic known for its four-tier Great Hall of Spins bonus and an above-average return. This page sets out the plain facts: who made it, how it plays, its RTP, and how the features work — without hype.
It is written to inform, not to promote. Nothing here recommends playing or depositing. Slots are games of chance built with a house edge, so over time they are designed to return less than is staked.
What It Is
Thunderstruck II is a video slot from Microgaming (now Games Global), released in 2010 as a much-expanded follow-up to the original Thunderstruck. It runs on 5 reels and 3 rows with 243 ways to win — a format Microgaming helped popularise with this game — and draws on Norse mythology, with Thor, Odin, Loki and the Valkyrie among the symbols, plus Thor’s Hammer, a longship and runes.
A quick note to avoid confusion: this is the standard Thunderstruck II. It’s a different game from the original Thunderstruck and from Thunderstruck II Mega Moolah, a jackpot version whose RTP is far lower (around 92%) because part of every bet funds the progressive jackpot. If you want this game’s stronger return, make sure you’re playing the standard version.
How It Plays
Set your bet (roughly $0.30 to $15) and spin; with 243 ways, wins pay for matching symbols on adjacent reels from the left, with no fixed lines. The heart of the game is reaching the Great Hall of Spins.
RTP, Volatility and Max Win
The news here is good. The RTP is 96.65%, which is above the industry average — a genuine strength, and Microgaming/Games Global is generally consistent on its RTP. It’s still worth a quick check on the game’s information screen, but this is a stronger return than many titles. Our guide to RTP explained covers why that matters over a long session.
The volatility is medium, so you can expect a reasonably balanced mix of wins rather than long dry spells — though the layered bonus means the biggest results come from the higher Great Hall tiers. The maximum win is around 8,000× your stake, a solid ceiling for a game of this type, but a rare theoretical outcome reached only through an exceptional bonus run, not something to expect.
Playing From New Zealand
You’ll find Thunderstruck II at online casinos that carry Microgaming/Games Global titles and accept New Zealanders. Rather than naming specific sites, the important thing is to check the operator itself: the legal backdrop changed in 2026, when the Online Casino Gambling Act 2026 created New Zealand’s first licensing system for online casinos, run by the Department of Internal Affairs (DIA). From 1 December 2026, only DIA-licensed operators may lawfully offer online casino games to New Zealanders. A game like this isn’t “licensed” in New Zealand — the casino offering it must be. Our overview of online casino licensing in New Zealand explains how that works, and you can browse more titles via our casino games section.
Practical Notes (Not a Strategy)
No strategy changes a slot’s odds — every spin is independent and random, and the features are never “due.” You’ll see “tips” about aiming to trigger the Great Hall repeatedly to unlock the Thor round; in reality you can’t influence when it triggers — it’s random, and progress simply reflects how often it has already happened. A few honest pointers: a better RTP still leaves the house an edge, so treat it as entertainment; try the demo/free-play mode first; set a firm time and money limit before you start; and remember bonus funds and free-spin offers carry wagering requirements (our casino bonuses guide explains the fine print).
Staying in Control: Responsible Play in Aotearoa
The layered, “unlock the next god” bonus structure is designed to reward continued play — which can encourage longer sessions than intended. Even an above-average RTP is not a winning strategy; the house still profits over time. Treat any slot as paid entertainment only — never as a way to make money or recover losses. Regulated operators must provide control tools such as deposit limits, reality checks and self-exclusion. Our guide to self-exclusion tools explains how they work.
Free, confidential help is available in New Zealand at any time — you do not need to be in crisis to use it.
Factual information disclaimer
This article is provided for general information only. It describes the features and publicly reported facts of the Thunderstruck II slot; it does not encourage gambling, does not recommend playing this game or depositing with any operator, and is not legal, financial or professional advice.
Gambling involves financial risk and can be harmful. RTP figures are long-run averages, not a promise of returns, and the maximum win is a rare theoretical outcome. Game details, RTP and availability can vary by casino and change over time — always check the in-game information before playing.
If gambling is affecting you or someone you know, free and confidential support is available: the Gambling Helpline Aotearoa on 0800 654 655 or at gamblinghelpline.co.nz, and the New Zealand regulator, the Department of Internal Affairs, at dia.govt.nz.
What is the RTP of Thunderstruck II?
It’s 96.65%, which is above the industry average — a stronger return than many slots. Note that the separate Thunderstruck II Mega Moolah jackpot version has a much lower RTP (around 92%), so check which one you’re playing.
What is the Great Hall of Spins?
It’s a four-tier free-spins bonus triggered by three or more Thor’s Hammer scatters. Early triggers give the Valkyrie round (10 free spins, wins ×5); triggering it repeatedly progressively unlocks the Loki, Odin and Thor rounds, with the later tiers adding cascading Rolling Reels and rising multipliers.
What is the maximum win?
Around 8,000× your stake — a solid ceiling, but a rare theoretical outcome reached only through an exceptional bonus run. It’s not a realistic expectation.
Is Thunderstruck II high or low volatility?
Medium — a fairly balanced pace of wins, though the biggest results come from the higher Great Hall tiers. Sources vary a little, so check the game’s information for its stated rating.
Where can I get help if gambling becomes a problem?
Free, confidential support is available in New Zealand through the Gambling Helpline Aotearoa on 0800 654 655. Support is available at any time, and you do not need to be in crisis to reach out.
