Slot machine-based bonus play—whether its free spins, pick’em games, multipliers, mystery jackpots, cascades, wheel bonuses, progressives or other new features—adds an extra element of anticipation, entertainment and potential rewards for the player; and for these reasons, remains a go-to mechanic for gaming machine producers and designers.

“Bonuses in slot games have long been a fundamental part of any game—they are a key reason why players play,” said Kathleen McLaughlin, vice president of marketing and product management, NOVOMATIC Americas. “It is where the creative focus of the developer and interactive curiosity of the player meets and creates compelling gaming entertainment.” 

“Today, bonus events are an essential design element for most any successful slot product, especially video slots,” added 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.’” 

Regardless of the type of bonus, players are looking for a bonus experience to be memorable, fun and something they can talk about and share with other people. Creativity and good mathematics just might be the key to the success of such slot bonus features. “Creativity gives players that memorable entertainment factor, and we’ll continue to see outstanding new concepts and iterations on how bonuses are delivered,” Walther said. “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.” 

Also worth mentioning are other game mechanics and cabinet features that help draw in the player and creates more interaction. “Larger screen sizes, new technology and enhanced hardware is allowing manufacturers to create more player interaction which is driving bonus features to new levels,” said Abhinay Bhagavatula, vice president, engineering and products at Eclipse Gaming. “In addition, game themes which allow players to reach new levels of bonus rounds and rewards thru the perception of skill are also heightening player entertainment.”  

Greg Colella, vice president product marketing at Scientific Games, believes that as the trend towards the layering of bonuses (where once a player is awarded a bonus, they have the opportunity to win other more lucrative bonuses) continues, game developers will experiment with skilled-based play options that offer rewards based, in part, on a player’s skill level. Also, as game makers continue to license brands, unique bonuses based on elements of these brands will continue to be developed, driving new innovations in bonusing.

Below are a few of the different bonus strategies game manufacturers are utilizing in their latest slot creations.


Potentially large free game wins on titles like China Shores have long been a favorite of Konami players. “When a lucky player watches those free game spins tally into hundreds of dollars, that becomes an incredibly memorable experience,” Walther said. 

Players will also see bonus features and events associated with Konami’s Xtra Reward series. Xtra Reward has been 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. Xtra Reward gives players an added bonus for an extra ante bet, for an additional boost while remaining in attainable range of the player’s desired bet level. 


Konami’s Agent
Konami’s Agent: Magnifying Jackpots, one of the the latest original Strike Zone releases, featuring art based on the Sherlock Holmes detective stories.


Drawing on the company’s roots in consumer entertainment, adventure-driven bonus features are another noticeable trend with Konami games. Castlevania-themed slots is one such game, allowing players to travel to Dracula’s Castle and battle against a series of harrowing foes for larger potential jackpot prizes. Meanwhile, in the new Purrfect Pirates series, players have the chance to shove off on various different bonus voyages with the game’s kooky kitty characters as they search for treasure. 

Konami’s Strike Zone has become one of the top new bonus features this year, with games including Star Watch Magma, Star Watch Fire, Celestial Sun Riches and Celestial Moon Riches. The Strike Zone is a special reel area that players are invited to expand in order to increase the odds of winning select bonus events whenever certain symbols land within its borders. As players increase their bet, the Strike Zone immediately expands to reflect the player’s added investment toward extra bonus opportunities. Players increase their extra bet amount to further expand the Strike Zone, where every wild eclipse symbol transforms to random 2x or 3x multipliers and each sun or moon symbol awards a wheel bonus if the free game feature is triggered. These single screen game themes for Concerto Crescent and Stack allow players to increase the Strike Zone by entire reel strips from left to right, up to the entire frame. Any random prize symbols that land in the Strike Zone instantly award a credit prize or a wheel spin bonus with guaranteed Mini, Major, Mega or Maxi jackpot. 

Agent: Magnifying Jackpots and Inspector: Sign of the Jackpots are the latest original Strike Zone releases, both featuring art based on the Sherlock Holmes detective stories.   

“There’s a very powerful element of excitement and anticipation in each spin when players can see the special symbols reeling across the frame as progressive meters tally higher and higher,” Walther said. With this in mind, Konami has recently released a number of symbol-driven progressive releases for single screen Crescent and Stack that have had exceptional results. Games like Lucky O’Leary Jackpots and Dragon Emblem Jackpots have built-in standalone progressives that players can claim by collecting the correct combination of colored jackpot symbols on the reels. Konami’s newest Castlevania-themed slot release, called Castlevania: Ring of the Heavens, also includes a symbol-driven progressive jackpot. Anytime a player lands a Feature Wild symbol on reels one and five, players enter the Castlevania Feature and follow the hero through a trial against the dark forces. 

A’Coins Matey!, an original new five-reel release for Concerto upright and Slant, uses instant credit prize symbols which allow players to watch their credit awards tally higher as they collect more credit symbols. Throughout game play, coin symbols appear across all reels with random credit prize amounts, and any that land with a collect symbol on reel five are instantly awarded along with a free game bonus. A pirate ship sails into the top screen to keep a tally on the credits, as the player begins a very memorable coin-collecting adventure, as long as the green ocean monster stays at bay.  

“Konami continues to show a leading edge in community-style, multi-station bonus entertainment—tracing back to the popularity of Titan 360 and rooted in the company’s history in amusement and arcade entertainment,” Walther said. “Because of its decades-long history in amusement and arcade, Konami is able to leverage that technology to bring new engaging formats to the casino sector that are unlike anything else available to market.” 


NOVOMATIC has been the producer of leading slot games in European and Latin American markets for decades. More recently, the company started to develop slots for the U.S. and Asia, as well as online and social gaming markets. 

Slot bonus play is attuned to the various markets and segments in which the games target. Popular themes may be adjusted for different bonus ratios dependent on customers’ tastes and regulations. “This dictates the freedom to create different types of bonus play,” McLaughlin said. “The history is deep, an example being NOVOMATIC UK company Bell-Fruit Games, having pioneered slot machines with various bonus concepts for more than 50 years. Over the years, impressive game mechanics and bonuses have been fine-tuned for specific market segments. A recent success here is the bonus-rich Batman series of games for European markets that includes bonuses such as the Bat Wheel of Fortune, the Power Up feature and the Joker Streak.”


Konami’s Agent
NOVOMATIC’S Enchanted Fortunes Linked Jackpot featuring bonus mechanics that connects to a four-level linked progressive.


A wide variety of bonuses that enhance the base game and use themes in creative ways are attracting attention. Free spins are widely implemented bonus events in slot games. Branded titles offer content that characterizes bonuses and develops stories. From Dusk Till Dawn is one such example for NOVOMATIC, featuring the Bonus Twister Wheel that leads to two special free games bonuses. In the Dancing Bonus, Salma Hayek’s character dances around the reels for 10 free spins, acting as a ‘Dancing Wild’ that can fill up the reels. The Mugshot Bonus starts with three free spins and the free spin counter resets to three every time a mugshot appears, with some engaging action along the way. In addition, the game features three random bonuses, each with its own volatility and that can trigger on any spin, as well as a two-level standalone progressive that randomly activates at any time and bet.

Standalone and linked progressives from NOVOMATIC have been big attractions with operators and players as well. “The Asian theme Asian Fortunes quickly became one of the best-selling NOVOMATIC games in the U.S. with its pick’em bonus that corresponds to a four-level progressive jackpot,” McLaughlin said. This concept was taken further with the Enchanted Fortunes Linked Jackpot that launched with a series of diverse themes, all featuring the same bonus mechanic that connects to a four-level linked progressive. While each game features different variations of math models, players search for a Wild symbol across all Enchanted Fortunes themes that may trigger a pick’em bonus and guarantee a jackpot win. Players select from 12 images that reveal different levels corresponding to a progressive jackpot level.


Hot Fire bonus from NOVOMATIC
The Hot Fire bonus from NOVOMATIC’S Dusk Till Dawn slot game.


In addition to unique free spin bonuses, random bonuses and mini-bonuses in themed slots such as From Dusk Till Dawn and MacGyver, new bonus concepts are often introduced in games. Recent concepts popular with players include the Extra Added Wilds feature in the Viking & Dragon slot where the Dragon breathes a fire of coins across the reels and awards 3-15 additional Wild coins. 

“New concepts for bonusing in slot games are only limited by imagination and new technologies will spur further creativity in this field,” McLaughlin said. “NOVOMATIC focuses on increasing player duration through bonuses and creating stimulating, unique gaming experiences every time a player engages with a game. Whether that is achieved through the theme, mathematics, land-based or social gaming, bonusing adds layers of entertainment and dimension to the overall experience.”


Scientific Games has a storied history when it comes to bonus play concepts and developments.

“Our legacy slot brands, Bally, Shuffle Master and WMS, were at the forefront of bonus play development in slot machines, incorporating some of the earliest bonus features like the re-spin, nudge, or bonus wheel, which grew in popularity,” Colella said. “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.”


Scientific Games Cash Spin Deluxe
Scientific Games Cash Spin Deluxe.


According to Scientific Games, free games or free spins continue to be a favorite of players and can be found in some form in just about every slot machine on the casino floor. The free games bonus also serves as a foundation for other types of bonuses with enhancements such as added wild symbols, locking symbols, raining or stacked symbols and modifications to reel sets.

Nearly every game in the Scientific Games slot library contains some sort of bonus play. Some of the most popular games incorporate one or more of the following categories of bonus play:

  • Free Games,where players are awarded a number of free spins.  Lock-and-spin variations of the free games bonus are currently featured in the successful Lock It Link and Ultimate Fire Link game series.
  • Progressive Pick Features, where players pick to match symbols for progressive jackpots.  This feature can be found in the company’s Duo Fu Duo Cai games, such as 88 Fortunes and 5 Treasures. In the Fu Bat Jackpot Feature, players pick to match Fu Babies symbols for progressive jackpots.
  • Scatter Pays, as seen in Quick Hit games, where when a specific number of scattered Quick Hit symbols appear on the reels, a corresponding jackpot or multiplier is awarded. This feature is oftentimes incorporated into a free game bonus as well.
  • Wheel Bonuses are another popular feature for the company where a wheel can award credit prizes, additional bonuses and progressive jackpots, as seen in Cash Spin Deluxe.
  • Specific Themed-based Bonuses, which are based on a licensed brand, such as the MONOPOLY Board Game Bonus in the company’s new MONOPOLY Hot Shot game, where players roll dice to move around the MONOPOLY game board to win additional bonuses and credit prizes.  

“Scientific Games is constantly striving to create new technologies to incorporate into our games and cabinets, as well as incorporating new technologies being developed by other industries,” Colella said. “These new technologies have the potential to spark the creation of new, innovative and increasingly interactive bonus play.”


Aruze Gaming has a rich history of unique bonus play concepts. It has experimented with many ways to trigger bonuses and unconventional ways for players to participate in them, as demonstrated in the company’s popular Paradise Fishing game. Close to 99 percent of slot games at Aruze now contain some kind of bonus play, according to press materials.

Aruze’s development team is reportedly highly influenced by the pachislot and pachinko parlors of Japan and this has always given its games a distinctive feel. The company believes that operators have an appreciation for the bonuses it has created that are enhanced by increasing the wager. They see Aruze is adding value to the player’s experience as they increase their overall spend. 

Some of the latest bonus strategies incorporated into slots for Aruze are its Leap to Riches games, the first in the company’s Activ-Play line of games where operators can choose how much they want skill to influence the overall RTP. 

The company stated that they are “excited to see how technology evolves, as new bonus game styles are frequently inspired by leading-edge technology. As players continue to become more sophisticated, games need to push the boundaries of innovation to really surprise them.” 


Bonus features have always been an essential design element for all of Eclipse Gaming’s slot products. Historically, Eclipse provided additional value to the player mainly through free spin bonuses.  As the company has expanded its product line, its focus is to provide the player with many levels of gaming entertainment through a variety of entertaining bonus features and compelling wins for the players.

“We place a high level of importance on appealing to a range of player styles, so we innovate our themes with a variety of bonus strategies including Free Spin Overloads, Wild Doublers, Double Wheel Bonus and Multi-level Wins,” Bhagavatula said.  

Two of the company’s most popular themes—Mermaid Multipliers and Super Slots of Cash—feature 10X Wild Multipliers on the first reel and award up to 10X the line win. Also, with its new Big & Bad: 3 Wild Pigs, the company incorporated free spin overloads, a pick bonus and multi-level wins to provide the player with more interaction, more entertainment and more rewards.

“All of our games support our mystery ‘must hit by’ progressive jackpots which create a tremendous amount of anticipation and excitement for the players to chase the jackpot as it gets closer to hitting,” Bhagavatula said. “In the next few months, Eclipse will also launch new games featuring Anyline Progressives which are tied directly to each of the nice paylines and have a higher hit frequency. We will also release new themes which incorporate persistent state bonusing.”


Through Oasis 360, Aristocrat has been developing bonusing modules as part of its casino management systems solution since the early 2000s. Through the years it has evolved its bonusing modules by incorporating multiple new elements. Recently, the company extended its bonusing applications into its kiosk, progressive and mobile platforms while continuing to provide a wide library at the nCompass player tracking unit.

“Bonus play is becoming much more popular as patrons seek a more rewarding experience with each trip,” said Thomas Castleberry, vice president of systems marketing at Aristocrat. “By utilizing systems bonusing, operators are now able to provide additional rewards to players beyond cash such as points, comps and prizes. Operators can define which slot events will trigger awards in the bonusing applications. This becomes an automated and personalized experience for the patron.”

Aristocrat believes both operators and players experience the most excitement through floor-wide promotions, specifically floor-wide mystery progressive bonusing. “Operators utilizing Aristocrat’s ONE LINK bonusing system to implement carded and uncarded Floorwide Mystery Progressive Bonuses have experienced a lift in coin-in and a reduction in issued free play, which has been a win-win for operators and players,” Castleberry said.

Some of Aristocrat’s latest bonusing strategies include floor-wide mystery progressives with consolation prizes. This helps to promote carded play and can help to increase visitation. 

Aristocrat is continuing to invest in technologies which encompass the entire player’s journey—from mobile and web-based applications to floor-wide and personalized casino applications, making sure its casino customers are able to provide the greatest level of excitement and enjoyment for their patrons and to gain a competitive advantage. “Eventually patrons will experience multi-touch bonusing which may involve all devices—phone, EGM and kiosk—to earn bonus rewards and receive the maximum benefit,” Castleberry said.


AGS is a global company focused on creating a diverse mix of entertaining gaming experiences for every kind of player, with roots in the Class II Native American gaming market. “Progressives add another layer of excitement to the bonus or bonuses of a game,” said Brett Vela, slot product manager at AGS. “Players now find themselves chasing a visible top award. We have had a ton of success in Class II with our floor-wide So Hot Progressive, and we continue to expand that into the Class III market with our Xtreme Jackpots library.”


AGS Xtreme Jackpots
AGS Xtreme Jackpots four bank with topper.


 Many of the company’s newer and most successful games offer players the ability to choose their own volatility. They often sacrifice a number of free spins to add additional wilds or lines into their bonus rounds.

 It’s no secret that signage and display technology has become much more advanced and AGS is incorporating this into slot bonus events. “Although our sign hardware is relatively simple, our sign content is designed specifically to create excitement and show achievability,” Vela said. “For example, our Xtreme Jackpots sign content displays anytime a player wins one of the progressive amounts.” 


Today, if it wasn’t for the mandated bingo card facsimile on the front of the machine, a customer would be hard pressed to tell the difference between a Class II and a Class III play experience… except in one vital area. The bingo card math on which Class II games are based is difficult to manipulate when it comes to certain styles of linked jackpot bonuses, at least compared to Class III slots that utilize random number generators.

This is where Ainsworth’s AnyBet product comes into play. Simply stated, AnyBet is a first-of-its-kind, patent-pending technology that offers Class II machine players the chance to win huge mystery progressive slot jackpots at any bet level. With AnyBet, a player can drop $0.25 into a machine and walk away with $5,000 or wager $0.40 and win more than $10,000.


Ainsworth’s AnyBet Class II
Ainsworth’s AnyBet Class II mystery progressive.


“AnyBet is the only Class II mystery progressive that pays the full amount of the progressive regardless of the wager,” said Dave Waters, director of technical services and hardware for Ainsworth, in the May issue of Slot Management & Marketing. “Our patented technologies provide true odds across all wagers and math models. The result allows linking of over 50 titles to a large progressive, which increments the jackpot more rapidly. We designed this to be given away very frequently.”

“The key innovation is in player fairness and engagement… games that require a match bet for progressives leave a smaller bettor out of contention for the progressive, and that makes the game less appealing and lowers the expected value of return for the player,” Waters added. “AnyBet solves this problem by giving every player true odds and a chance to win a life-enhancing progressive.”