Danger High Voltage slot review

Danger High Voltage slot facts

Big Time Gaming was founded in Sydney in 2011 and is best known for inventing Megaways. Evolution announced a deal to buy the studio in April 2021. Danger High Voltage is not a Megaways game, though: it uses a fixed 6x4 grid.

The 4,096 figure is simple arithmetic: each of the 6 reels has 4 positions, and 4 × 4 × 4 × 4 × 4 × 4 = 4,096. A win needs matching symbols on adjacent reels from the left, in any row.

How the features work in Danger High Voltage

Two kinds of wild

The game has two wild symbols. Wild Fire acts as a standard substitute, and Wild Electricity applies a 6x multiplier to the wins it helps form. On a ways game, a single wild can be part of several combinations at once.

The heart scatters

Landing three or more heart scatters takes you to a choice screen. You pick one of two free spins rounds, and the two work in very different ways.

Gates of Hell trades spin count for persistence: fewer spins, but every wild that lands stays for the rest of the round. High Voltage gives more than twice the starting spins and relies on multiplier wilds instead. The game's paytable shows exactly how the multipliers and extensions work in your version, and independent listings such as OLBG's Danger High Voltage page (opens in a new tab) describe the same two options.

Gates of Hell or High Voltage: thinking about the choice

Neither round gives you a way to beat the house edge. The 96.22% RTP is published for the game as a whole, and each spin in either round is random, so the choice is about the style of bonus you enjoy.

• Gates of Hell builds up a grid of sticky wilds over a short round. It suits players who like watching a feature develop spin by spin.
• High Voltage gives a longer round of 15 spins where each wild can carry a multiplier. It suits players who prefer more spins, accepting that many may pay little.
• Either way, the outcome of each spin is random, and past rounds tell you nothing about the next.

We haven't seen a published per-round RTP, so we don't suggest one round returns more than the other. Treat the choice as a matter of preference.

Danger High Voltage RTP: a £20 budget in practice

A 96.22% RTP means a house edge of 3.78%. Standard game maths gives an expected loss of £20 × 3.78% ≈ 76p on £20 staked.

Medium-high volatility sits between steady and explosive. With 4,096 ways, each spin has far more possible combinations than a 10-line game, but the bigger returns depend on the free spins, so a 20-spin session at £1 can easily finish without one.

The maximum win is a cap, not an expectation. Reaching it is extremely rare, and most sessions cost money. If you play for an hour at 50p a spin and make 300 spins, you'd stake £150, with an expected loss of about £5.67.

How Danger High Voltage plays on a phone

Big Time Gaming's games run in HTML5, so Danger High Voltage loads in casino apps and mobile browsers. A 6x4 grid is wider than a classic 5x3 game, which can make symbols small on a narrow screen held upright.

1. Install a UK-licensed casino app and complete age and identity verification.
2. Set a deposit limit before your first deposit, when the app prompts you.
3. Search the lobby for Danger High Voltage; the sequel is a separate game.
4. Read the paytable for the RTP and the rules for both free spins rounds.
5. Choose a stake you can repeat comfortably within your budget.
6. Spin manually, and when the hearts land, pick your round on the choice screen.
7. Check net spend and time on screen, and stop at your limit.

If symbols look cramped, try turning the phone sideways; our landscape mode entry and playing on Samsung Galaxy page have more on screen layouts.

UK rules for Danger High Voltage

The Gambling Commission's slots stake limit guidance (opens in a new tab) applies to this game as to every online slot: £5 a spin maximum for adults aged 25 and over, and £2 for those aged 18 to 24. Our stake limits page explains the dates.

The Commission's responsible product design standard (opens in a new tab) also requires at least 2.5 seconds between spins and rules out turbo, slam-stop and celebrating returns that don't beat your stake. Autoplay is banned, and net spend and time played must be visible as you play.

Since a Gambling Commission warning in January 2020, feature buy-ins are not offered to British players, so the free spins choice only appears after landing heart scatters. Our game design rules page and the 2.5-second rule FAQ cover the rest.

Danger High Voltage review: pros and cons

It's a strong pick for players who like having a say in how a bonus plays out. Read more on how independent reviewers such as Gambling.com (opens in a new tab) describe the game if you want a second view.

Big Time Gaming slots like Danger High Voltage

For more reel-shifting games, see our Megaways explainer, or head back to the slots hub for every review.

Where to play Danger High Voltage with a welcome offer

None of our partner offers lists Danger High Voltage as a qualifying game, so look in each app's lobby to see whether it's available. All three offers are for new customers aged 18+, and terms apply.

At PlayOJO, depositing £10 or more for the first time brings 80 free spins on Big Bass Bonanza at 10p each. There's no wagering, and spin winnings are paid as cash. Northern Ireland is excluded, the deal can't be combined with other offers and it's only available through the designated link.

Coral gives 100 free spins on selected games when you deposit and bet at least £10 on slots between 1 October 2026 and 1 February 2027. The spins are 10p each, must be accepted within 48 hours and are valid for 7 days, with no wagering on winnings. Deposits using Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards don't qualify.

Ladbrokes rewards a £10 spend on slots with 50 free spins a day for 10 days, so up to 500 spins at 10p on selected games. Claim each day's spins before 23:59; they're valid for 7 days with no wagering. Prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits are excluded, and as Coral and Ladbrokes are both run by LC International Limited, you may not be able to sign up to both as new.

18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.