As with any entertainment, people want to have an experience that is memorable, fun and something they can talk about with others, and this does not prove false when it comes to bonus play in slot machines.

Since the introduction of bonus play in slot machines, bonus features have become more and more prevalent in game play and help draw players to new machines. Bonus events also represent a key component of the modern day casino experience; and operators actively seek slots with new bonus concepts that will create excitement throughout the entire casino floor when hit by a customer.

“When IGT introduces new slot game concepts at trade shows around the world, our customers are motivated to get a first look at our games’ bonus content,” said Dallas Orchard, chief product officer, gaming for IGT. “When IGT launched Sphinx 4D at last year’s G2E, crowds of people queued up to be among the first to experience IGT’s 4D bonus content. With licensed properties, such as The Ellen DeGeneres Show Video Slots and Betty White Video Slots, players were curious to see how IGT incorporated the property’s iconic intellectual property to create an entertaining and authentic brand experience.”

Other slot suppliers concur that slot bonus popularity among both players and operators is at an all-time high.

“Bonus events are an essential design element for most any successful slot product, especially video slots,” said Steve Walther, senior director, marketing and product management for Konami Gaming. “Whether it’s a free game feature, progressive jackpot, bonus adventure, pick ‘em game or any of these combined, they have become necessary ingredients to the core gaming experience that players expect. Bonus events provide that boost of excitement that players anticipate and celebrate. They help build additional engagement between the game and the player looking for that ‘something extra’.”

“I’m not sure bonus play can become more popular, as I think the acceptance of games with bonus play is near universal at this point,” added Jason Pawloski, lead game designer for Ainsworth Game Technology. “At this point in time, it is hard to imagine a player unwilling to try a popular new game because they prefer games without a bonus.”

When it comes to satisfying this slot bonusing demand, two types of play mechanics seem to dominate—free games and free spins

“The most popular types of bonuses are free games or free spins, which can be found in just about every modern slot machine in some form or another,”  said Greg Colella, vice president of product marketing, gaming division for Scientific Games. “The free game also serves as a foundation to other types of bonuses with enhancements such as added wild symbols, locking symbols, raining or stacked symbols, and modifications to reel sets.  Multipliers and pick games are also a popular bonus.”

Of course, bonus game concepts and strategies continue to evolve over time as slot manufacturers seek to produce new, market-defining experiences based on customer feedback and experience. 

“About 10 years ago, there was a major shift towards an extreme number of bonuses within a game,” said Andrew Burke, vice president slot products at AGS. “At that time, players would play just to get into a specific bonus round. Many of these games had five, six, or even seven different types of bonus rounds. However, players started to realize that with so many bonus rounds in a game, they couldn’t win any real-money because the payout was spread very thinly. More recently, the market has shifted back towards very simple bonus rounds, like free spins that happen faster, pick ‘em bonuses, and progressives. Our philosophy is to keep bonus rounds fun, simple and efficient with meaningful winning opportunities, which is what we’ve found most players are after.”

In addition to innovations in gaming hardware and game concepts, the future of slot bonusing may also include theme and social play components, thereby leveraging base slot games to appeal to players who are comfortable with greater digital offerings.

“These offerings will need to be fun and engaging enough to compete with top options available in the largest marketplaces, such as Apple and Google Play stores,” said Kristofor Jacobson, director of product management, systems marketing, Aristocrat Technologies.

Whatever the approach, one thing is certain: bonusing technology is constantly evolving, and slot vendors are adapting to the changes.

“Bonus games will always continue to evolve as the player base looks for new and exciting ways to enjoy playing new products,” Pawloski, said. “The future will involve not just new game concepts but innovations in the gaming hardware.”

Below is a look at some of the different bonus strategies game manufacturers are utilizing in their latest slot creations.


The bonus strategy at AGS boils down to two concepts—fast play and meaningful wins, items the company believes with attract a customer whether they are playing for the first or 20th time.

“Players love the quick, efficient nature of our bonus features and love having the opportunity to win 60-70X their bet instead of 4 or 5X their bet,” said Burke. “We do this through free spins, pick ‘em features and progressives. We’ve also added fun little Easter eggs within some of our games, which make the experience more interactive and surprising, and it offers a non-monetary type of bonus.”

One recent AGS release that embodies this bonusing practice is Golden Guardians, an opulent, Asian-themed Class II game available on AGS’ ICON cabinet that features striking golden lion statues on the top screen surrounding four progressive meters. The symbol set features a dragon, phoenix and various Asian-themed items. Using the PowerXStream pay evaluation, Golden Guardians offers 576 ways to win, according to a recent press release. When at least one bonus symbol lands on reels two–four, the free spins bonus is initiated and awards anywhere from eight to 64 free spins with retriggers possible.

Golden Guardians also features both Super Lucky Streams and Super Lucky Jackpots during the base game, which randomly trigger and add a large number of symbols to reels two, three and four. Super Lucky Streams can be triggered in the base game and at the beginning of the free spins bonus and can continue throughout the free spins, whereas Super Lucky Jackpots are only available in the base game.


Every game at Ainsworth has bonusing play incorporated into it. The company has predominately focused on free spins and large wins in bonus games. In the last few years Ainsworth has expanded on this attraction by adding more new features to bonuses while keeping the possible large wins players are used to getting from its products.

Wheels and multipliers are among the most popular bonus features offered by Ainsworth. In addition, new cabinets with larger screens allow for expanding reel arrays which open further opportunity for unique bonus mechanics.

“At Ainsworth, our expanded reel arrays in new games like PAC-MAN WILD EDITION, Rumble Thunder and Toro Treasure have utilized expanding reels to take full advantage of the 40-inch screen on our A640 cabinet,” Pawloski said. “Players are excited for the extra lines in a bonus.

“In general, bonusing fads change every few years,” Pawloski added. “Right now ‘hold and respin’ play in bonuses is a trend, as several manufacturers have included that kind of gameplay. Down the road, it will change when someone develops the next trend.”

Over the next year, Ainsworth plans to boost its bonus play diversity—players will see a lot more different bonusing styles with a great emphasis on player experience. “We continue to mix it up by experimenting with new features such as symbol driven reel expansions, while mixing in the classics that everyone knows and loves, such as free spins with multiplied wins, sticky wilds and re-spins,” said Pawloski. “I think hold and respin type of features will continue to do well for many companies in the near term.” 


Respin bonus technology is only one of many new game mechanics making a splash in the slot bonus space.

“From what we’re seeing, the most popular system-based bonusing program at present is the must-hit-by ‘value’ mystery progressive,” said Jacobson. “This type of program has an incrementing top award, and patrons know that it will hit before it goes beyond an advertised maximum. Operators like it because it drives excitement, and because they have the ability to fine-tune these bonusing programs to respond to their players and casino floor.”

This month Aristocrat E*Series line of entertainment-style games unveiled the new Midnight Stampede line with the launch titles Midnight Rumble and Super Stampede, both of which are now available on Aristocrat’s Helix, Helix+ and ViridianWS cabinets. Both titles in the Midnight Stampede family offer a two-level “Must Hit By” jackpot with achievable levels of $1,250 (major) and $250 (minor). Jackpots can be won randomly on any bought game, and when the player increases the wager, it proportionally increases the odds of winning jackpot prizes. Also, both titles have a new game mechanic—2X symbols that multiply multipliers with up to 32x wins on each pay line. The game also includes STAMPEDE MAX stacks and free games features, where two mini-games replace all of the major symbols on the reels with random or player-selected symbols. A new “blackout” win cycle shows winning symbols and blacks out non-winning symbols.

Midnight Rumble and Super Stampede are the first E*Series games to allow players to use “auto-play,” a new feature that enables players to select a number of games to play on auto-play. Midnight Rumble and Super Stampede also offer flexibility to operators, who can chose from different denomination and progressive parameters.

“We believe bonus play is becoming more popular with casino players, as they look for something ‘extra’ that adds to their gaming experience,” Jacobson said. “We continue to work in this area, because we want to participate in every category that is important to our customers.”


International Game Technology PLC (IGT) approaches bonusing from several different angles. For example, IGT’s sees in-game bonuses as an ideal way to integrate additional excitement and anticipation into a casino game. “When creating these bonuses, we take into account a series of player-focused considerations such as preferred volatility, pace, mechanics and bet eligibility,” Orchard said. “If the bonus is within a game that features licensed properties, we evaluate the authenticity of the brand experience and push ourselves to ensure that the bonus at hand will meet and exceed the brand expectations of the player. “

The company also leverages its systems solution portfolio to initiate floor-wide bonuses and celebrations with solutions such as IGT Advantage. IGT’s system-driven bonuses provide a solution for creating operating efficiencies, driving excitement on a casino floor and cultivating world-class patron loyalty programs. “Combining solutions such as our IGT Advantage casino management system with products such as Service Window and Media Manger enable our customers to deliver personalized, real-time incentives, rewards, and marketing materials while patrons enjoy their favorite slot games,” said Orchard.

IGT’s product portfolio contains a wide spectrum of entertaining bonuses such as mystery events, bank-wide celebrations, free games, content-rich vignettes and fast-paced events within high-volatility games with the company’s most iconic in-game bonus event being the widely recognized Wheel of Fortune “Wheel Bonus.”  IGT has applied that Wheel of Fortune bonus format in a number of different ways—on physical wheels, digital wheels and on the oversized wheel of its MEGATOWER cabinet.

The bonus events within IGT’s Video Reel Edge (VRE) skill-based game family represent another area that is garnering substantial interest from operators. IGT’s VRE games such as Texas Tea Pinball and Atari Centipede feature a standard base game and then give players the choice of a free games bonus, or a skill-based bonus event where a player’s performance in the bonus will influence their bonus reward.

Bonus content plays an integral role in many of IGT’s slot products. “We believe that bonuses represent a key component of the player experience and contribute a heightened level of player engagement and anticipation to gameplay,” Orchard said. “For example, games within IGT’s TRUE 3D product family are rich in thematic 3D content that players can enjoy in 5.1 surround sound. Similarly, the company’s new Fort Knox games on the CrystalCurve cabinet both feature refreshed versions of the iconic bonuses that propelled the success of the original Fort Knox games.  From IGT’s mechanical reel product portfolio, games such as IGT Pinball and Top Dollar Premium feature distinctive, player-favorite bonuses that IGT has retained and revamped in the latest versions of the games.”


Community-style, multi-station units have become incredibly popular method of bonus event delivery in recent years. Konami in particular has begun to establish a specialty niche in this area, beginning in 2013 with the launch of Titan 360. This 10-foot tall, 3-ton machine has been a huge attraction and strong success at casinos across North America for years. 

A few months ago Konami released an all-new bonus game for Titan 360 called Dragon’s Orb Jackpots. At the center of Titan 360 is a unique mechanical bonusing feature which allows players to spin a giant metallic ball across of series of prize slots. The use of gravity as a determining factor to the outcome is uniquely appealing to players and adds an additional element of thrill and mystery.

Konami is currently in the midst of pioneering its next advancement for the multi-stations: Crystal Cyclone. Similar to its proven predecessor, Crystal Cyclone connects individual video slot stations around a mechanical bonusing ring for optimal thrill and excitement. Players have the opportunity to enter several different bonus game events involving brightly-colored balls that race around a central lighted roulette-style track.

“These unique styles of multi-station bonus entertainment stem from Konami’s lasting legacy in proven amusement and arcade games,” Walther said. “We’re able to leverage that technology to bring new engaging formats to the casino sector that are unlike anything else available to market.”

Nearly all Konami games feature bonus events in some form or another. Huge free game wins on titles like China Shores have long been a favorite of Konami players. Players also see bonus features and events associated with Konami’s Xtra Reward series. “Xtra Reward has been very popular since it first appeared with games like China Shores Boosted Wins & Spins, Quest for Riches and even more recent favorites like Dragon’s Law and Solstice Celebration,” Walther said.  “Xtra Reward gives players an added bonus for an extra ante bet, so it’s nice boost while remaining in attainable range of the player’s desired bet level.”

Drawing on the company’s roots in consumer entertainment, adventure-driven bonus features are another noticeable trend with Konami games. In its latest, Castlevania themed slots, allow players to travel to Dracula’s castle and battle against a series of harrowing foes for increasing potential jackpot prizes.

One of Konami’s latest bonus game innovations making its way to market this summer is Smash Smash Festival. This game features an innovative linked progressive mechanism that progresses the number of available prizes in a winner-takes-all prize pool rather than traditional meters. The prizes are represented by piñatas that players smash open to reveal their award. The mystery trigger event either allows the player to redeem all the piñata prizes during Smash Time, or continue to add toward the growing prize pool. Guests can watch the incrementing prizes continue to pile up, similar to how a progressing credit meter grows to captures interest and attention. 

“Bonus events featuring multipliers have been doing exceptionally well for Konami’s most recent releases,” Walther said. “Sparkling Roses is one of the newest games in our Multiple Lines 15 REELS series and randomly throughout primary play, mystery multipliers appear over select picture symbols for wins up to 144x. Most of all, players are looking forward to the free games, during which the mystery multiplier feature is active for every spin.

“Creativity and good mathematics are key to the success of slot bonus features,” Walther added. “Creativity gives players that memorable entertainment factor, and we’ll continue to see outstanding new concepts and iterations on how bonuses are delivered. Multi-station and community-style bonuses can be especially powerful because they carry an inherent aspect of social gratification as players watch and celebrate the feature as a shared experience. However, the long-term success of a title is largely reliant on the game math and how it keeps players engaged over time.”

Beyond the exciting games from Konami, the award-winning SYNKROS casino management system empowers operators to deploy system-delivered bonusing to any equipped machine, regardless of manufacturer. True-Time Tournaments are awarded to carded players based on defined criteria and can be launched simultaneously or made available to redeem on-demand. “It is a slot tournament style bonusing product with a library of available themes,” Walther said. “SuperSeries is a randomly-triggered, floor-wide bonusing tool with a number-pick, lotto-style award. Players pick a set of five numbers and watch the official selection animated through a diverse variety of games.”


Scientific Games legacy slot brands, Bally and WMS, were at the forefront of bonus play in slot machines incorporating some of the earliest bonus features like the re-spin, nudge or bonus wheel, which grew in popularity.  “We have continued to innovate in the area of slot bonusing and we even offer bonusing on slot machines through our casino management system products such as our Elite Bonusing Suite, which rewards players at the game, regardless of who manufactured it,” said Colella.

To date, predominantly all of its slot library contains some sort of bonus play, and mostly all of Scientific Games slot game bonuses fall into one of three categories: free games, in which the player is awarded a number of free games, during which other features such as multipliers and additional bonuses can occur; progressive picks, like in its popular 88 Fortunes and Dancing Drums games, where the player picks to match symbols that correspond to certain progressive awards; and scatter awards, like the ones prevalent in a player-favorite Quick Hit series, where a specific number of jackpot reel symbols appear anywhere on the reels to award the progressive jackpot.

“With the current climate of slot machine bonuses, I foresee more game makers dabbling in skill-based bonuses, offering features and awards that depend in part on a player’s skill level in certain types of gaming activity,” said Colella.  “Our new Space Invaders slot gives players  the option to play a bonus based on classic arcade game of the same name, shooting down alien ships and winning more credits if they perform better in the game. In Space Invaders, players also have the option of opting out of playing the skill-based bonus game and playing the luck-based free spin bonus.” 

In other recent Scientific Games bonusing news, the company recently announced a strategic licensing agreement with NTN Buzztime, to deliver Buzztime trivia as part of Scientific Games’ Elite Bonusing Suite (EBS) offered to casino operators around the world.  The game will provide a unique bonusing experience and will help casinos provide exciting new tournaments that keep players engaged and entertained.  

As part of this agreement, Scientific Games will offer a customized version of Buzztime’s Trivia in single packs and bundles directly to their casino customers for a license fee; Buzztime Trivia can be delivered through Scientific Games’ EBS and create a community gaming experience; and during slot tournaments, casinos can end device downtime and mitigate lost revenue as players can compete in Buzztime bonus games for prizes right at the device.

“Casinos want to increase player duration, create engaging experiences, and increase loyalty,” said Tom Doyle, vice president of product management at Scientific Games. “Buzztime has achieved these goals for over 30 years at bars and restaurants, where the dynamics are similar to those at casinos. We think introducing fun bonusing games like Buzztime in our Elite Bonusing Suite will be an exciting new way for casinos to attract and engage players, especially during slot tournaments.”

“This agreement exemplifies our strategy to leverage our existing game investments into new revenue streams,” said Ram Krishanan, CEO for NTN Buzztime. “Our software—standalone or integrated into our customizable handheld tablet—is highly scalable. And, Buzztime has a strong reputation for working well with other companies to achieve their goals. We are excited to grow our business by bringing our expertise to more markets and to deliver impact for their customers.”