Thor Trials of Asgard is a Norse mythology slot from Green Valley Games, the studio most casino lobbies list simply as GVG. Released in March 2020, it seats the thunder god beside the reels and fills the grid with hammers, horns, longships and rune-etched stones. The theme is well-worn territory, but the game earns its place through a layout that refuses to sit still: the reels grow taller as you play, and when they do the number of winning combinations jumps from a couple of hundred to more than a thousand.
How Thor Trials of Asgard plays
The starting grid is five reels by three rows, paying 243 ways. There are no fixed lines to keep track of; matching symbols simply have to land on consecutive reels running left to right, so any position on a reel counts as readily as any other. Stakes run from 10p up to £20 a spin, and all 243 ways stay live at every stake level.
The mechanic that gives the game its shape is the expanding grid. Reels can grow to a fourth row, and with the taller layout in play the ways count climbs to 1,024. Wilds arrive as dynamic reel wilds in three sizes, covering one, two or three positions at a time, and it is those larger wilds that turn an otherwise ordinary spin into a full column of matching symbols.
Land three or more horn scatters and the free spins round opens with ten spins. A multiplier steps up every time you hit a winning spin during the round, topping out at 10x, while wild stacks appear at double height for the duration. Further scatters landing mid-feature add extra spins on top, so a good run can stretch well beyond the ten you began with.
Thor Trials of Asgard RTP, volatility and max win
The published RTP is 96%, which sits squarely on the average for online slots. Operators sometimes run titles at alternative RTP settings, so it pays to open the in-game paytable at whichever casino you play rather than assuming the headline figure applies everywhere.
Volatility is generally rated medium-high. In practice that means the base game ticks along with modest returns while the meaningful money sits behind the free spins and the expanded reels, so a session can run flat for a stretch before anything substantial arrives. Budget with that rhythm in mind: a stake you are happy to repeat fifty or a hundred times suits this game far better than a large one-off punt.
Max win is the figure to treat with caution. Green Valley Games does not headline a single number and the slot databases disagree, with 25,000x the stake listed most often and higher figures quoted in places. Whichever is right, it describes a theoretical ceiling that needs the multiplier, the expanded grid and the biggest wilds to align at once, not an outcome anyone should plan around.
Playing Thor Trials of Asgard
The game is widely distributed and appears across UK-licensed casino lobbies, usually filed under GVG or Green Valley Games in the provider filter. You can try the free demo on this page with no account and no deposit, which is the sensible way to see how often the reels expand and how quickly the multiplier builds before committing real money. The casinos listed further down the page carry the title. Where a welcome offer includes free spins on it, those spins come with wagering requirements and expiry dates attached, so read the terms in full before opting in.
Is Thor Trials of Asgard worth playing?
Several years on it looks its age next to the current crop of releases, and there is no bonus buy or cascading engine to keep the feature-hungry crowd busy. What it does have is a clean ways-to-win format built around one genuinely good idea, and the expanding reels give the base game more shape than most Norse slots manage. It suits players who want a straightforward spin with a rewarding round to chase, and it will frustrate anyone who needs constant action. Whatever you decide, set a deposit limit and a time limit before you start, and read our responsible gambling guide if you want practical tools for keeping play under control.
Frequently Asked Questions
Thor Trials of Asgard has a published return to player of 96%, in line with the average for online slots. Some operators run alternative RTP configurations, so check the in-game paytable at the casino you are playing at.
It is usually rated medium-high. Base game returns tend to be modest and the larger wins are concentrated in the free spins round, so expect quiet spells between the bigger hits.
The game starts as a five reel, three row grid with 243 ways to win. When the reels expand to a fourth row the ways count rises to 1,024.
Landing three or more horn scatters starts the round with ten free spins. A multiplier increases after each winning spin up to 10x, wild stacks appear at double height, and additional scatters during the feature award further spins.
Yes. The demo on this page runs on play money with no account, registration or deposit needed, so you can test the expanding reels and the free spins round before staking anything.
It was developed by Green Valley Games, a studio commonly abbreviated to GVG, and released in March 2020. It is distributed to a wide range of UK-licensed casinos.