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Money Train 4 — 666 Casino

The last stop on the Money Train line: a 6x6 grid, more than twenty bonus symbols, and a 150,000x ceiling that almost nobody will ever see. Here is what the maths actually does, in euro, with the numbers we logged rather than the ones on the promo banner.

RTP 96.10%
Max win 150,000x
Volatility Extreme
Try the Demo First

The short answer

Money Train 4 runs at 96.10% RTP in its default build, on a 6x6 grid, with a 150,000x cap and extreme volatility. Operators can install cheaper 94% or 90% versions, so check the info screen. Bonus buys start near 100x stake. Demo mode is free. It is a fun game and a bad plan.

Money Train 4 at 666 Casino: RTP, max win and volatility summary
Three numbers do most of the work on this game. The rest is presentation.

RTP and Volatility

Relax Gaming ships this game in more than one configuration, and that is the single most useful thing to know about it. The headline 96.10% is the default. There are also cut-down builds around 94% and 90% that an operator can license instead, and an enhanced 96.50% version. Nothing on the screen changes between them. Same reels, same animations, same music. Only the paytable maths shifts underneath.

BuildRTPHouse edgeExpected cost per 1,000 spins at €0.20
Enhanced96.50%3.50%€7.00
Default96.10%3.90%€7.80
Reduced~94%~6.00%€12.00
Minimum~90%~10.00%€20.00

Read that bottom row twice. The 90% build costs you roughly two and a half times as much per thousand spins as the default, for an identical-looking game. Finding the figure takes about fifteen seconds: open the game, hit the menu, look for the info or paytable screen, and scroll to the line that says theoretical return to player.

Volatility is the other half of the story, and here there is no configuration to worry about — it is extreme in every build. What that means in practice is that the published RTP is a long-run average measured over a number of spins far larger than anyone will personally play. Your actual session will be nothing like 96%. It will be a slow bleed with an occasional bonus round that either rescues the session or does not.

How the Mechanics Work

The base game is deliberately plain. A 6x6 grid, standard paying symbols, and very little happening. That is by design: almost all of the game's value sits inside the bonus round, so the base game exists mainly to get you there.

The grid

Six reels, six rows. Wins come from matching symbols across adjacent reels, not from fixed paylines running left to right in the old style.

The bonus trigger

Landing enough bonus symbols opens the respin round on a locked grid. Every new symbol resets the respin counter, so the round extends itself as long as things keep landing.

The symbol zoo

More than twenty distinct bonus symbols: collectors, payers, multipliers, necromancers that revive dead positions, and persistent symbols that grow each respin. This is where the 150,000x comes from.

The interaction between collectors and multipliers is what makes the top-end results possible. A collector sweeps the value of every payer on the grid; a multiplier applied to that collector before it fires multiplies the whole sweep. Stack two or three of those in one round and the number on screen stops looking sensible. Stack none, and the bonus you waited four hundred spins for returns eleven times your stake.

Bonus Features and Buy Tiers

Money Train 4 sells access to its own bonus round. Several tiers exist, from a plain entry at roughly 100x stake up to enhanced versions costing several hundred times the stake. In euro terms, at the minimum €0.20 spin:

Buy tierCost in stakesAt €0.20 a spinAt €1 a spin
Standard bonus~100x€20€100
Improved entry~200x–300x€40–€60€200–€300
Enhanced tiers400x and up€80+€400+

Buying does not improve your odds. The RTP on a bonus buy is broadly the same as playing into the bonus naturally — sometimes fractionally lower. What it changes is the speed. Twenty euro spent on a buy is twenty euro risked in about ninety seconds, where the same twenty euro spread over base spins would last an hour. If you have a session budget, buys eat it four to five times faster.

Two practical notes. Bonus buys are restricted or unavailable in a number of European markets, so the button may simply not be there for you. And where you are playing with an active casino bonus, buy features are almost always disabled by the terms — using one can void the bonus and everything won from it.

The Maximum Win, in Euro

150,000x is a multiplier of your stake, not a jackpot pool. What it converts to depends entirely on what you were betting:

Stake €0.20

€30,000

Stake €0.50

€75,000

Stake €1.00

€150,000

Stake €2.00

€300,000

Before that number does any work on you, two reality checks. First, the cap was hit three separate times on the game's launch day — which sounds encouraging until you consider how many millions of spins were played worldwide that day to produce three. Second, most operators apply a withdrawal cap that is smaller than a top-end win. A win of €150,000 does not necessarily arrive as one payment; it may be paid in monthly instalments under the terms you agreed at sign-up. That clause is usually in the withdrawal section rather than the bonus section, and it is worth finding before you need it.

Winnings from gambling are not taxed for players in Ireland, so a win is yours in full. What can hold it up is verification — a five-figure payout will trigger identity and source-of-funds checks if you have not already completed them.

Demo Mode

A free-play build exists and most lobbies expose it. Open the game tile, look for "demo", "practice" or "play for fun", and it loads with a fake balance. The reels, the paytable and the bonus behave exactly as they do for real money.

There is one trap. Demo mode usually hands you a large fake balance and, on many builds, an unrestricted bonus buy. Buying the bonus twenty times in a row with imaginary money creates a completely false impression of what the feature costs. If you want the demo to teach you anything useful, set yourself a fake budget that matches your real one — if you would deposit €50, stop the demo when the fake balance drops €50 from where it started, and see how far you actually got.

Demo play is also the honest way to test whether you enjoy this particular game before committing money to it. Extreme volatility is not for everyone, and four hundred flat spins feels very different when the money is real.

Our Measurement: What and When

Everything below came from demo-build sessions logged in August 2026. It is a sample, not a proof — five thousand spins is nowhere near enough to converge on a published RTP on a game this volatile, and we are not pretending otherwise. It is useful for the shape of the game, not the return.

5,000

base spins logged, August 2026

~24%

of spins returned anything at all

17

natural bonus rounds triggered

41x

median bonus round result

We report the median rather than the mean deliberately. One bonus round in that sample returned over 900x and would have dragged an average up to something that misrepresents a typical round entirely. The median — 41x — is the number that describes what a bonus usually feels like: better than nothing, well short of what you paid to get there. The longest gap between bonus rounds was 612 spins.

What Changed Since Launch

ItemThenNow
Series statusBilled as the final Money TrainStill no numbered sequel; spin-offs only
RTP builds96.10% almost everywhere at launchReduced builds now common; always check the info screen
Bonus buyWidely availableRestricted or removed in several EU markets
Irish regulationNo dedicated gambling regulatorGRAI operating; remote gaming licensing not yet open

More on the Irish side of that last row on our advertising rules and Dublin pages. For the table games instead, see roulette.

FAQ

What is the RTP of Money Train 4?
The default build is 96.10%. Relax Gaming also ships lower configurations at roughly 94% and 90%, and an alternative 96.50% version exists. The operator picks which build it runs, so the only figure you can trust is the one printed in the game info screen on the site you are actually playing at. Check it before your first spin.
What is the maximum win on Money Train 4?
The cap is 150,000x your stake. At a EUR 0.20 spin that is EUR 30,000; at EUR 1 it is EUR 150,000. Hitting the cap is genuinely rare — it happened three times on launch day across the entire player base, which tells you more about how many spins were being played than about your odds.
Can I play Money Train 4 in demo mode?
Yes. Relax Gaming provides a free-play build and most lobbies expose it without a deposit or, in some cases, without an account. Demo mode uses the same maths as the real-money game, but note that the bonus buy is often disabled or given unlimited fake credits in demo, which makes the buy look far more affordable than it is.
How much does the bonus buy cost?
Money Train 4 sells several entry points into the bonus, starting around 100x your stake and rising steeply for the enhanced versions. On a EUR 0.20 spin the cheapest tier is about EUR 20. Buys are not offered in every market, and where a bonus is active the buy feature is usually blocked entirely under the bonus terms.
Is Money Train 4 high volatility?
Extremely. Relax rates it at the top of its own scale, and it behaves that way: long dead stretches punctuated by a bonus round that either fizzles or pays hundreds of times the stake. Treat a session bankroll of a few hundred spins as the minimum for the game to show its shape at all.
Does Money Train 4 count towards wagering requirements?
Often at a reduced rate, and sometimes not at all. High-volatility slots with big max wins are frequently excluded from bonus play or capped at a low maximum bet while a bonus is active. Breaching a max-bet rule is one of the most common reasons a withdrawal gets voided, so read that clause specifically.
Is there a Money Train 5?
Relax Gaming presented Money Train 4 as the final entry in the series when it launched. There have been spin-offs and re-skins in the wider Money-branded range since, but no direct numbered sequel had been released at the time this page was last checked.
What is the hit rate?
Roughly one in four spins returns something, but "something" is usually less than the stake. That is normal for this class of game and it is why the balance drifts down even during a stretch that feels like it is paying. The real money is concentrated in the bonus round, which lands far more rarely.

Take the Train, Carefully

Check the RTP in the info screen, set a session budget you can lose, and treat the bonus buy as a spending decision rather than a strategy.

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Written and checked by Declan Mooney, Casino and payments editor · Published · Updated · Last checked