
Ainsworth is one of the most established and forward-thinking developers in the slot gaming industry. Originally recognised for its land-based slot machines, the company has successfully expanded into the online casino market, where its titles continue to gain widespread popularity.
Ainsworth is particularly well known for producing visually appealing slot games, including Must-Hit-By progressive jackpot slots. These games include a built-in upper jackpot point, a feature that many players notice early on, even if the full detail behind it is not immediately obvious.
In this blog post, we explore the basic idea behind Must-Hit-By slots, touch on how their jackpots behave, look more closely at the mechanics behind them, and consider whether these games may appeal to you if you choose to play.
Read on to learn more.

At a basic level, a Must-Hit-By slot machine is a type of progressive jackpot game that displays a visible jackpot range. Early on, it is enough to know that the jackpot does not rise endlessly and that there is a stated point it does not pass.
These games are sometimes described as “mystery” jackpots, although the labels are not always used in exactly the same way by every provider. What matters for players is that the jackpot grows over time and has a clearly shown ceiling.
Behind the scenes, the jackpot begins at a starting value and increases as qualifying wagers are placed by players who choose to play. A small portion of those wagers feeds into the jackpot pool. The key feature, hinted at by the name, is that the jackpot is awarded before or at the displayed maximum figure, such as £500, £1,000, or £20,000.
At this stage, it is useful to note that the displayed maximum does not indicate the precise point at which the jackpot is paid. It simply marks the highest value the jackpot reaches. The actual payout may occur at any value between the starting amount and that upper figure, though the exact trigger remains unknown to players.
Although the jackpot range is visible, the outcome of each spin remains based on chance. Certified random number generators determine results, supporting fairness and unpredictability in line with UK regulatory standards.
Some players assume that choosing to play as the jackpot climbs higher improves their personal odds. This belief often appears early in discussions about these slots, but the reasoning behind it, and why it is misleading, becomes clearer with closer examination. Acting on that assumption may encourage spending beyond personal limits, which is why a measured approach is important.
Must-Hit-By slot machines award their jackpots at some point before or at the stated maximum amount. For instance, if a game displays a Must-Hit-By £20,000 jackpot, the payout occurs somewhere between the reset value and £20,000.
This information provides a broad outline rather than a timetable. The jackpot might be won soon after it resets, or it might continue rising until it sits close to the upper figure. Both outcomes form part of normal game behaviour.
The uncertainty becomes clearer once the trigger itself is considered. Each qualifying spin carries a chance to release the jackpot, and this probability exists regardless of the number shown on the jackpot meter. The meter reflects the current value rather than a countdown or signal that a payout is approaching.
Players who choose to play may notice that jackpots sometimes appear to slow as they approach the top of the range. This impression is common and links to how the game allocates contributions and probabilities, rather than to any unfair practice. The crucial point is that the jackpot does not exceed the stated maximum and is awarded within that range.
It is also important to understand that being the person spinning at the exact moment the meter reaches its upper figure does not automatically result in a win. The jackpot is awarded through a qualifying random event, not simply because a number on the screen is reached. This distinction explains why the games remain unpredictable, despite showing more information than traditional progressives.
For anyone choosing to play, it helps to remember that no visible indicator promises an outcome, and chasing a jackpot may lead to spending beyond what feels comfortable.
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The mathematical design behind Must-Hit-By slot machines builds on the ideas introduced earlier, adding more detail to how jackpots grow and are awarded. Rather than relying on a fixed spin count or a hidden trigger point, these jackpots operate within a defined range using probability-based models.
One element worth expanding on is how contributions behave across the jackpot range. While part of each qualifying wager feeds into the jackpot, the rate at which the displayed amount increases may vary. Early in the cycle, the jackpot might appear to climb more quickly. Later, the visible increases may become smaller, even though contributions continue.
This behaviour is often referred to informally as meter movement. For example, in a hypothetical Must-Hit-By £1,000 slot, the jackpot might rise by several pounds during its early phase. As the value approaches £980 or £990, the increases might appear far less noticeable. This reflects how the game prevents the jackpot from passing its upper figure.
Another factor is that many online Must-Hit-By jackpots are shared across multiple players. If you are betting alongside others, each person may be wagering different amounts and at different times. The exact portion of each wager that feeds the jackpot is usually not shown, as it forms part of the game’s internal design.
Throughout all of this, RNG technology determines outcomes. No timing method or waiting strategy influences the result. Joining a game with a high jackpot value does not provide a dependable advantage, and the jackpot might just as easily be awarded earlier or to another player.
All licensed Must-Hit-By slots are independently tested to confirm that jackpots are awarded within their stated limits and that the games operate as advertised.
Whether Must-Hit-By progressive slots appeal to you depends on personal taste and expectations. Like all slot games, they exist primarily for entertainment, and results are driven by chance rather than decision-making skill.
Some players like the visible jackpot range, which may feel more engaging than a progressive jackpot with no upper display. Seeing that a jackpot does not rise indefinitely adds a sense of momentum as the value increases.
Others are drawn to the possibility of winning a larger prize than is usually available on standard non-progressive slots. Although Must-Hit-By jackpots are often smaller than major networked prizes, they tend to be awarded more frequently, which some players find appealing.
That said, it is important to remain realistic. These slots do not guarantee wins, and choosing to play at higher jackpot values does not remove uncertainty. The casino advantage still applies, and spending may exceed returns over time, as with all gambling activities.
If you choose to play Must-Hit-By slots, responsible gambling should always be a priority. Set a clear spending limit, read the game rules carefully, and treat any win as a bonus rather than an expectation. Slots should never be viewed as a way to generate income or to recover previous losses.
If you’re playing, only wager money you are prepared to lose, take regular breaks, and keep gambling as an occasional form of entertainment. If gambling begins to affect your finances or well-being, seek help as early as possible. Independent organisations such as GamCare and GambleAware provide free, confidential support for anyone who needs it.
**The information provided in this blog is intended for educational purposes and should not be construed as betting advice or a guarantee of success. Always gamble responsibly.