Slotegrator unveils the top ten bonus features that have grabbed player attention in 2025 - and three that need to be avoided at all costs.
As strange as it might be in this day and age, the inclusion of bonus features and special events in casino games is a relatively new idea.
Renowned casino software and gambling solution provider Slotegrator dove into the topic of which in-game features were the most popular and what players found so fascinating.
Here is a look at what they discovered:
At the top of Slotegrator’s list is, unsurprisingly, free spins as a bonus. Online casinos use this feature as a way to welcome new players while simultaneously encouraging them to try new slot machines.
What makes free spins engaging is the allure of a generous payday, without the need for a deposit before claiming and playing your spins.
Some casinos offer variations of this offer, such as no-deposit bonuses and wager-free bonuses, which lower the barrier to entry for new players. In each case, the house is covering the cost of your spins and will pay you your winnings for the privilege.

Another popular feature in modern slots is the bonus buy. Instead of waiting for the reels to trigger a special round, players can pay to jump straight into the action.
What makes bonus buys appealing is the immediacy. By paying between 30x and 100x your base bet, you gain instant access to bonus rounds where the bigger wins usually hide. Some games even boost their RTP during these rounds, which adds to the attraction.
Players enjoy the heightened risk-versus-reward dynamic. The cost is steep, but the potential payout makes it worthwhile for those who prefer to cut straight to the good part.
Created by BigTimeGaming, the Megaways to win mechanic has become a fan favourite thanks to its ongoing impact on paylines and jackpot potential.
All Megaways slots need to have six reels, with the feature adding from 2 to 7 symbols with each new spin. This variable symbol option allows it to offer up to 117,649 ways to win to each game it appears in.
When it comes to the excitement and unpredictability of landing a big slot win, nothing comes close to matching the engagement levels of Megaways.

Cascading reels, also known as Tumbling or Avalanche reels, are a fantastic way to trigger multiple consecutive wins from a single spin.
Traditional slot games only offer a single win per spin, but games with Cascading reels see winning symbols removed and new symbols taking their place. When these symbols align with paylines, additional wins are on the cards.
Win multipliers do precisely what the name says. Whenever a win is triggered that meets preset requirements, developers can trigger multipliers that magnify the payout from its base value to more than 100x in some cases.
Slotegrator found that the most common way in which game developers integrate this feature into a slot machine is to pair it with other options such as Wild symbols, Scatters, free spins, and special bonus round multipliers.
Progressive jackpots can also come with win multipliers that are only available during their bonus round as a way to catapult wins to the advertised jackpot level.
What makes sticky wilds appealing is their ability to raise the chances of a win with every spin, given that they stay active over several spins.
They appear during free spins or bonus rounds, often on specific reels like the middle three. The more sticky wilds that drop and hold, the greater the chance that a big payout is around the corner.
Players love the tension these symbols create. Knowing that at least one reel is locked with a wild makes every subsequent spin feel like the one that could deliver a jackpot-level win..
Surprisingly, hitting a progressive jackpot is only at number seven on the list, which speaks volumes to the amount of immersion and entertainment offered by other features.
A progressive jackpot is a big win that is not fixed in its size, but increases with each spin of the reels. The jackpot provider takes from 1% to 5% of the value of each round and adds it to the prize pool.
Some developers, like Relax Gaming, have carved out their niche in the jackpot category, with Dream Drop, a jackpot that pays out before the total reaches $3 million. With a seed value of $1.5 million, this means players are constantly anticipating the next big win!

Gamification features are an anomaly in this list as they do not add any payout value to the casino games you play, but focus on enhancing the overall player experience.
By playing specific games or reaching preset levels, you can earn badges, unlock achievements, gain tickets to slot tournaments, and even climb a leaderboard. The sense of accomplishment and pride in showcasing your achievements is a valuable commodity in its own right and adds a sense of community.
Hold and Win slots have become a popular genre with players who enjoy the fast-paced action offered by respins.
The feature basically works like sticky Wilds, where special symbols trigger the feature and become sticky on the reels when they do so. You then have 3 respins to collect as many sticky symbols as possible before the feature ends.
Filling the game grid with symbols tends to pay out a grand jackpot prize.
Slotegrator found that games and events that encourage group cooperation or friendly competition ranked highly with the broader gambling community.
The most popular of these are livespin events, multiplayer slot tournaments, community jackpots, and live dealer sidebets. These scenes feature players engaging with one another as they vie for each other's spots on the leaderboard, or conspire against the house to “beat” the dealer.

Slotegrator also asked what players didn’t enjoy, and this is what they found:
Now that you know what works and what doesn’t, be sure to visit our recommended Slotegrator casinos to pick up a generous welcome bonus and feature-rich casino games.
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