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FrançaisNitropolis 4 Slot
Nitropolis 4 is the first game in the series where a Nitro Reel can hold a multiplier, and two or more in view multiply each other. The Booster also returns, as two screens above an expanding grid, with 8 features including Max Rows and Garbage Collect.
Nitropolis 4 Demo
Look for a Nitro Reel showing x4 to x12 instead of symbols, then see what it does to the next win. Watch the two Booster screens too, which can award features as the grid grows.
Nitropolis 4 and the arrival of Nitro Multipliers
Multipliers are the real addition here. ELK released the game in February 2023, with the gangs drilling for Nitro on a disused oil rig, and kept the avalanche structure of Nitropolis 3 running from 4 rows to 8. A Nitro Multiplier sits inside a Nitro Reel with a value of x4, x6, x8, x10 or x12, applies to all wins in view, and compounds with any others, so x4 and x6 together give x24.
That changes how you read the board. Until now a Nitro Reel has been about ways. A multiplier version adds no ways of its own, because it counts as one symbol and acts as a blocker, but it makes everything else pay more. The two-screen Booster is the other big change, rewarding a growing grid and staying active once the grid is full.
Nitropolis 4 game data
| Studio | ELK Studios |
|---|---|
| Released | Feb 2023 |
| RTP | 94.0% |
| Volatility | 8 of 10 |
| Max win | 50,000x bet |
| Hit rate | 18.1% |
| Bet range | 0.20–50 EUR |
| Grid | 6×4 → 6×8 |
| Ways to win | 4,096+ |
| X-iter™ | Yes |
| Free demo | Yes |
An 18.1% hit frequency is the joint lowest in the series and volatility is 8 of 10, so most spins return nothing. RTP is 94.0%, a long-run theoretical figure that the in-game rules state for your version.
How a round unfolds
Base spins open at 4 rows and 4,096 ways, and each avalanche adds a row, up to 8 rows and 262,144 ways before Nitro Reels add more. Winning symbols explode while Nitro Reels and Nitro Multipliers in the win stay and respin during the refill. The cycle continues for as long as wins keep coming.
Paying symbols come in 1x1, Super 2x2 and Mega 3x3, as the Epic 4x4 of the previous game has gone. The Booster can act before the reels stop, when it moves upward as the grid grows, and alongside any win at full height, so reaching 8 rows does not end its activity.
Feature guide: multipliers, Booster and bonus
Multipliers and the Booster do most of the work, and the bonus inherits both.
Nitro Multiplier
This is a blocker covering two positions that holds x4, x6, x8, x10 or x12. It multiplies all wins in view, and several multiply each other. It counts as one 1x1 symbol whatever its size indicator, and the ways reset once it spins out. Nitro Upgrade raises its value and Redrop keeps it on the board. The catch is simple: it pays nothing alone, so a multiplier landing on a quiet board has nothing to work with.
Booster features for the main reels
Five of the 8 features work on the main reels. Max Rows jumps straight to 8 rows. Both Ways adds right-to-left pay, lasting through the avalanche cycle in the base game and for the remaining free spins in the bonus. Redrop keeps bonus symbols, wilds, multipliers and Nitro Reels once wins run out. Garbage Collect removes every instance of one random symbol, and Nitro Appear, labelled Nitro Reel on the product sheet, places a Nitro Reel or big Nitro Reel of any size.
Booster features for Nitro Reels
Nitro Wild, Nitro Upgrade and Nitro Match each select one Nitro Reel at random. If none is in view the feature stays pending in the Booster until a Nitro Reel appears or the round ends, so it is not lost straight away. Nitro Match works through a fallback order: a symbol in view that creates a win, then an adjacent Nitro Reel, then the highest-value symbol on the neighbouring reels.
Free spins and the safety level
Three to six bonus symbols award 8, 12, 16 or 20 free spins, with all Nitro Reels sticky. Any Both Ways or Max Rows active on the triggering spin switches off on entry. The safety level starts at 4 rows and climbs one row per winning free spin. Stacked Nitro Reels and big Nitro Reels can lift it several rows at once if they sit above the level a regular win provides, which makes early big reels especially useful.
Super Bonus
One super bonus symbol among the bonus symbols upgrades the round to the Super Bonus, played with Max Rows and Both Ways activated. Super bonus symbols only appear inside Nitro Reels, and each counts as one however large the reel. The same check applies to retriggers during an ordinary bonus, so a retrigger containing one can change the rest of the round rather than merely adding spins.
Nitropolis 4 X-iter modes and prices
The three cheapest modes each buy one altered spin, and the two dearest buy a bonus round.
| Mode | Cost | What it does |
|---|---|---|
| Bonus Hunt | 2x | A single spin with more than double the bonus chance. |
| Nitro Booster | 10x | A single spin where the Booster always provides 2 features when activated. |
| Super Spin | 25x | A single spin played with Max Rows and Both Ways activated. |
| Bonus | 100x | Guaranteed entry to the ordinary bonus game. |
| Super Bonus | 500x | Guaranteed entry to the super bonus game, all free spins with Max Rows and Both Ways. |
X-iter is not available in every market, and only the base game can activate it.
The €50 stake limit, 50,000x cap and 94.0% RTP explained
Read the top bet and the cap together: stakes stop at €50, half the €100 allowed by the first two games, while the cap is 50,000x rather than 10,000x. At €2 a round can reach €100,000, and at €50 it can reach €2,500,000, the game's stated maximum exposure. If you stake under €50 anyway, the lower ceiling costs you nothing.
The 94.0% RTP is one point below the previous game, or an extra €1 of theoretical loss for every €100 staked over a very long run. The rules also quote the probability of hitting the maximum win, but that value fills in only when the game loads, so look it up there.
Where this game sits in the series
Compared with the previous game you gain Nitro Multipliers and the Booster screens, and you lose the Epic 4x4, a point of RTP and the lower volatility. The bonus table, safety level and X-iter price ladder all carry over. Nitropolis 5 keeps the multipliers at identical RTP, volatility and hit frequency, then adds the NPD Holding Cell, a Boss Battle and a three-flipper Booster with 11 features. Nitropolis 2 has the older top-reel version of the Booster.
Nitropolis 4 pros and cons
What works
- Nitro Multipliers compound, so x4 and x6 together make x24
- The Booster keeps awarding features after the grid reaches 8 rows
- Pending Nitro features wait for a Nitro Reel rather than vanishing
- Stacked Nitro Reels can lift the safety level several rows at once
What to watch
- Multipliers block a position and can land with nothing to multiply
- More than four spins in five pay nothing, given the 18.1% hit frequency
- 94.0% RTP is well below the first game's 96.1%
Who should play Nitropolis 4
Nitropolis 4 suits players who want the avalanche game with multipliers on top, and who are happy for a large share of spins to do very little in between. It is also the simplest way into multipliers, before the Holding Cell and Boss Battle add further layers. Skip it if you prefer a steadier hit rate or a higher stated RTP, as the earlier games offer both.
Nitropolis 4 questions answered
What RTP does Nitropolis 4 pay?
The published RTP is 94.0%. Individual sessions can land far from that long-run theoretical figure.
What is the biggest possible win on Nitropolis 4?
The maximum is 50,000x the placed bet, and a game round ends if it is reached. That is a cap rather than a likely outcome.
Is there a demo of Nitropolis 4?
Yes. The free version here uses credits in place of money.
How do you get free spins in Nitropolis 4?
Three or more bonus symbols award 8, 12, 16 or 20 free spins. With a super bonus symbol among them, you get the Super Bonus with Max Rows and Both Ways.
How do Nitro Multipliers work?
A Nitro Multiplier appears in a Nitro Reel with a value from x4 to x12 and multiplies all wins in view. Several in view multiply each other.
