The Stormforged slot is a 2023 Hacksaw Gaming game with five reels, four rows and 14 paylines, rated high volatility, with a top RTP of 96.41%. Its Wild Portals open stacked wilds that can carry multipliers or reveal treasure, and its main bonus, Surtur’s Vengeance, keeps wilds sticky for the whole round.
14 fixed paylines on a 5 × 4 grid: wins pay from the left along those lines.
Wild Portals only open when they will complete a win, and can reveal multipliers or cash chests.
Surtur’s Vengeance free spins hold the first wild on each reel in place for the round.
96.41% is the top RTP; lower versions are in use, so check the help screen first.
In the UK there is no autoplay, no turbo and no bonus buy, and stakes are capped at £5 (£2 for 18–24s).
Developer
Hacksaw Gaming
RTP
96.41% (lower versions exist)
Volatility
High
Layout
5 reels × 4 rows
Ways to win
14 paylines
Released
2023
Main feature
Wild Portals and Surtur's Vengeance free spins with sticky wilds
Stormforged slot: the short version
Stormforged is a Norse-myth slot from Hacksaw Gaming, the studio behind Wanted Dead or a Wild. It is built on a compact layout, just 14 lines across a 5 × 4 grid, and puts nearly all of its interest into wilds: portal wilds in the base game and sticky or moving wilds in two free spins rounds. The fire giant Surtur and the storm god’s hammer give the features their names.
As with most Hacksaw games, the base game is lean and the bonuses carry the return. That makes it a high volatility slot machine: expect long runs of small or no wins, and occasional rounds that pay many times the stake.
How the Stormforged slot machine pays on 14 lines
Fourteen lines is a small number for a 20-position grid; many 5 × 4 games use considerably more. Fewer lines means a symbol has fewer paths to complete a win, so base-game wins are less frequent, and more of the value has to come from features. The lines are fixed, so your stake always covers all 14. The game’s paylines diagram in the help screen shows each path.
Choose your stake, which covers all 14 lines.
Press spin; the RNG decides the result, portals included, at that moment.
Symbols land on the 5 × 4 grid and line wins are checked from reel 1.
If a portal symbol can complete a win, it opens a stacked wild on its reel.
Any multipliers or treasure chests revealed by the portal are applied.
Three or more bonus symbols start a free spins round; otherwise the spin pays and ends.
Stormforged layout compared with other Hacksaw 5 × 4 games
The Wild Portals are the base game’s main feature. When a Hand of Surtur symbol lands, it can tear open a portal that fills its reel with a stacked wild. According to published descriptions, it only does so when the portal will complete a winning line. That sounds generous, but it isn’t extra value: the RNG has already decided the result, and the portal is simply how a winning outcome is shown.
What makes the portals interesting is what they cut through. If the portal passes a regular wild, that wild reveals a multiplier; several multipliers on one line win are added together. If it passes a treasure chest, the chest reveals a cash prize as a multiple of your stake, and a multiplier on the same reel can apply to it. Possible multipliers and chest values are listed in the rules. Our pages on wild multipliers and stacked wilds explain the building blocks.
What a Wild Portal can reveal
Portal passes through
Result
Effect on the win
Nothing special
Plain stacked wild
Completes the line
Regular wild
Multiplier wild
Multiplies the line win; several add together
Treasure chest
Cash prize
Pays a set multiple of the stake
Wild and chest together
Multiplied cash prize
The wild’s multiplier applies to the chest
Stormforged free spins: Surtur’s Vengeance and Warriors of the Storm
Stormforged has two free spins rounds, started by different bonus symbols. More symbols mean more spins; the help screen lists the counts.
Surtur’s Vengeance
This is the round named in the game’s headline feature. The first wild to land on each reel becomes a sticky wild for the rest of the round, with a limit of one per reel. Wilds from the triggering spin can also stick. As more reels hold a wild, more of the 14 lines are part-filled before each spin, so the round tends to build as it goes.
Warriors of the Storm
In the second round, a hammer symbol turns its reel into a storm reel, a full-reel wild. On later spins, either a storm moves that wild reel one step to the side or a warrior adds a multiplier to it. It combines ideas from walking wilds and wild reels, and multipliers on the same win add together.
Both rounds can award extra spins. We don’t quote how often either round starts: Hacksaw publishes figures for markets where its buy options are sold, and they don’t describe a game without buys.
Stormforged RTP: 96.41% and the lower versions
The top Stormforged RTP is 96.41%, which is slightly above the typical figure for online slots. Lower versions are also in circulation, and casinos choose which to offer. The figure applying to you appears in the help screen; our page on RTP variants explains why studios publish several. The second table shows how much the version matters, using an illustrative lower setting.
Stormforged cost per 100 spins at the top RTP
Stake
Total staked
Average return at 96.41%
Average cost
10p
£10
£9.64
£0.36
50p
£50
£48.20
£1.80
£1
£100
£96.41
£3.59
£2 (limit for 18–24s)
£200
£192.82
£7.18
£5 (limit for 25+)
£500
£482.05
£17.95
1,000 spins at £1: top version vs an illustrative lower version
No Stormforged max win appears here: the figures in circulation are not ones we could check. Look in the rules screen, where the ceiling is expressed against your bet, and scale it to your stake. Reaching it would take a free spins round with several large multipliers on one line, which is extremely rare, and the round ends once the cap is hit.
With only 14 lines and most value held in the features, the game’s high volatility is easy to feel: a typical session is a series of small line wins and blanks with the occasional portal multiplier. Our guide on slot volatility and budgets explains how to plan for that.
How to find the Stormforged RTP in the game
Open Stormforged at the casino and tap the menu or info button.
Hacksaw Gaming holds a Gambling Commission licence, and its UK games follow the responsible product design standard (opens in a new tab) in force since 31 October 2021: at least 2.5 seconds per spin, no autoplay, no turbo or quick-stop, no celebration of returns at or below your stake, and your net position on screen. The buy options sold for Stormforged in other markets are not part of versions supplied to Great Britain; see bonus buy in the UK.
Online slot stakes are limited to £5 per spin for players aged 25 and over, since 9 April 2025, and £2 for 18 to 24-year-olds, since 21 May 2025. The demo is free to play after age verification. Our online slot stake limits page has the detail.
Thunderstruck II is the classic of the genre and a gentler game; Le Viking is Hacksaw’s lighter, medium-volatility take. Stormforged sits at the steep end. Browse more on the Norse and Viking slots page.
Stormforged myths
Portals that only open on wins make the game easier. They are part of how a result the RNG already chose is displayed; the RTP doesn’t change.
A run of portal wins means a bonus is near. Spins are independent and the bonus has no countdown.
Sticky wilds carry over after free spins end. They last for the round only.
Wild Portals add multipliers and cash prizes to the base game
Two clearly different free spins rounds
Simple 14-line structure
Drawbacks
Few lines means many quiet base-game spins
High volatility can use up a budget quickly
Lower RTP versions are common
Max win not confirmed by a trusted source
It suits players who enjoy feature-led games and accept long quiet spells between them. If you want frequent small wins, a lower-volatility game will fit better; our guide on how to choose a slot machine can help.
Where to play the Stormforged slot in the UK
Hacksaw Gaming’s games are offered by many UK casinos, but game libraries change. Search for Stormforged at each casino and confirm the RTP version before you play. None of our partners’ welcome offers is set on Stormforged.
Coral: 18+ new players who deposit and bet £10 on slots get 100 free spins at 10p on selected games, with 48 hours to accept and seven days to use them, no wagering on winnings. Ladbrokes: 18+ new customers who play £10 on slots get 50 free spins a day for ten days, up to 500, 10p each on selected games, no wagering. PlayOJO: 18+ new UK customers (excluding Northern Ireland) get 80 free spins on Big Bass Bonanza after a first deposit of £10 or more, no wagering. Some deposit methods don’t qualify; full terms apply. Find more games in our slots hub.
Set a deposit limit before you start. If you want to stop altogether, GAMSTOP (opens in a new tab) self-exclusion covers every UK-licensed online casino, and the National Gambling Helpline is free on 0808 8020 133.
Coral and Ladbrokes are both run by LC International Limited (Entain). If you already hold an account with one Entain brand, you may not be able to open a new account with another; check the terms before signing up.
Significant terms: 18+. New players only. Offer runs 01/10/2026 to 01/02/2027. Deposit (certain types excluded) and bet £10+ on slot games to get 100 free spins (selected games, £0.10 each, 48 hrs to accept, valid 7 days). No wagering on free spin winnings. Deposits by Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read the Coral reviewLicence: LC International Limited, UKGC account 54743. Offer checked 5 October 2026.
Significant terms: 18+. New customers only, from 14/11/25 until further notice. Certain deposit methods excluded. Deposit and spend £10+ on slots for 50 free spins a day during the first 10 days after first deposit and registration (max 500, £0.10 each, selected games, claim before 23:59 each day, valid 7 days). No wagering. Prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read the Ladbrokes reviewLicence: LC International Limited, UKGC account 54743. Offer checked 5 October 2026.
Significant terms: 18+. New UK customers (excluding Northern Ireland). First deposit only. Minimum deposit £10. 80 free spins on Big Bass Bonanza, £0.10 each. No wagering requirements; winnings paid in cash. Cannot be used with any other offer. Only available to players who arrive through the designated offer link. Full T&Cs apply. GamCare.org.uk
Read the PlayOJO reviewLicence: Skill On Net Limited, UKGC account 39326. Offer checked 5 October 2026.
18+. Gambling should be entertainment that costs money, not a way to make it. Decide a budget before you play: plan a slot budget. Free, confidential help: National Gambling Helpline 0808 8020 133.
Frequently asked questions
What is the Stormforged RTP?
The top Stormforged RTP is 96.41%, slightly above the usual figure for online slots. Lower versions are also used, and the casino chooses which to run, so check the help screen in the game before you play. Over 100 spins at £1 the top version costs about £3.59 on average, but high volatility means a single session can differ a lot. How to find a slot’s RTP shows the steps for any game.
What is the Stormforged max win?
It isn’t a figure we could verify, so we don’t give one. Stormforged’s rules screen expresses the ceiling as a multiple of your bet, so a 20p stake and a £2 stake give very different cash caps. Reaching it would need a free spins round with large multipliers combining on one line, which is extremely rare, and play stops once the cap is reached. More in max win caps.
How do the Wild Portals work in Stormforged?
A Hand of Surtur symbol can open a portal that turns its reel into a stacked wild, and it only does so when that wild will complete a winning line. If the portal passes a regular wild, the wild reveals a multiplier; if it passes a treasure chest, the chest reveals a cash prize. Multipliers on the same win add together and can apply to a chest. See our wild multipliers page for how multiplier wilds work elsewhere.
What is Surtur’s Vengeance in Stormforged?
Surtur’s Vengeance is one of the two free spins rounds. In it, the first wild that lands on each reel becomes sticky and stays for the rest of the round, with one sticky wild allowed per reel. Wilds on the spin that started the round can stick too. As more reels hold a wild, more lines are partly complete before each spin. The spin counts are listed in the help screen. Our sticky wilds page explains the mechanic.
Does Stormforged have more than one free spins bonus?
Yes. Besides Surtur’s Vengeance, there is Warriors of the Storm, in which a hammer turns a reel into a full wild reel that can move sideways or gain a multiplier on later spins. The two rounds are started by different bonus symbols, and both can award extra spins. Spin counts and multiplier ranges are in the game rules. Our page on how free spins work on slot machines covers the general rules.
How many paylines does Stormforged have?
Stormforged has 14 fixed paylines on a grid of five reels and four rows. All 14 are active on every spin, so your stake always covers them, and wins pay from the leftmost reel along a line. Fourteen is a low number for a 5 × 4 grid, which partly explains why base-game wins are fairly sparse and the features matter so much. Our paylines explainer compares fixed lines with ways and clusters.
Can I play the Stormforged demo for free?
Yes. After the casino has confirmed you are an adult, which British rules have required for free-play games since May 2019, the demo runs on play credits at no cost. It uses play credits and shows the Wild Portals and both free spins rounds, so it is a useful way to learn the game. A good or bad demo run tells you nothing about the real game. Our demo slots vs real money slots comparison explains the differences.
Who makes Stormforged?
Stormforged is made by Hacksaw Gaming, a studio launched in September 2018 and headquartered in Malta. Its parent company, Hacksaw AB, has been listed on Nasdaq Stockholm since 25 June 2025, and the studio holds a Gambling Commission licence. Hacksaw is best known for Wanted Dead or a Wild and makes slots, scratchcards and instant-win games. Our Hacksaw Gaming provider page lists more of its slots with published figures.
Can I buy the Stormforged bonus in the UK?
No. Stormforged is sold with several buy options in other markets, from a bonus-hunt mode to direct entry into either free spins round, but versions supplied to players in Great Britain don’t include them. You reach the bonuses only by landing the bonus symbols during normal paid spins, at a stake within the £5 and £2 limits. For why, see bonus buy in the UK.
Is Stormforged high volatility?
Yes, Stormforged is rated high volatility. With only 14 lines, base-game wins are relatively infrequent, and much of the return comes from portal multipliers and the free spins rounds. That pattern means long quiet spells are normal and a small budget can run out before a feature lands. Set your limits before you start. Our volatility explainer shows how volatility affects the way a session feels.
Gambling can be addictive. Free, confidential help is available 24 hours a day from the National Gambling Helpline on 0808 8020 133. Visit GamCare.org.uk and GamCare, or block yourself from all UK-licensed gambling sites with GAMSTOP.
This site contains adverts. We may earn commission when you sign up through our links. Advertiser disclosure.
We use no tracking cookies. We store one item in your browser to remember this notice. Casino sites may set their own cookies after you follow an advert link. Cookie policy
