Popular Online Slot Themes for 2021

Popular Online Slot Themes for 2021

From ancient Greece and Norse mythology, to space, movies and fairytales, slot machines feature the themes players crave. There are thousands of themed slot machines available in 2020, each one offering a unique set of bonus features and payouts.

You can now choose from a huge range of legal online slots in Pennsylvania. But what are the most popular slot machine themes found at the best casinos? Let's explore why developers revisit the same themes time and time again.

Why Are Themed Slots So Popular?

Every slot game has some kind of theme, whether it be on the casino floor in Las Vegas, at a brick-and-mortar casino in Philly or at one of our top-rated online PA casinos. It might be as simple as Egypt or animals, but the theme will inform the symbols and bonus features you will find in the game.

Slot game developers love to revisit the same slot machine themes as they know they will be a hit with a large portion of players. Gamblers like familiarity, especially if a theme is associated with big-paying bonus features.

For example, Microgaming's Thunderstruck slot is nearly 25 years old. The game has proven so popular that most other developers now have their own Norse-themed slot.

And the large developers will spend big bucks to launch a branded game based on a popular Hollywood movie or TV show. Players are familiar with the source material and will likely be more comfortable playing the game.

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Popular Themed Slot Machines for 2020

There are dozens of slot themes available now, with thousands of games for those who love playing slots for real money at the best PA casinos. We've selected some of the most popular themes, together with a few recommended games. Try your luck and play play free pa slots today.


Take a trip to China and play the best Asian-themed slots on the market. With a heavy emphasis on luck and Chinese New Year, Asian slots are usually crammed with lucky images such as lions, red lanterns and gold coins.

You can usually find a bonus game or two in the best Asian-themed slots. Hit a Jackpot Bonus in WMS's Dancing Drums or win free spins with a wild symbol.

Recommended Slots: Lights (NetEnt), 88 Fortunes (Shuffle Master), Lion Festival (Konami)

Action & Adventure

If you are a slot player who wants some more action in your online gambling, an adventure-themed slot is for you. Take a trip into the wild with heroes such as Lara Croft or Rich Wilde, or take out the machine gun and shoot for glory in games like BetSoft's The Slotfather.

Everyone loves some high-octane action when they watch movies, so why not enjoy some adrenaline when you gamble? Soak in the up-tempo music, loud sound effects and big jackpots with an action-themed slot.

Recommended Slots: Rich Wilde's Book of Dead (Play'n GO), Tomb Raider (Microgaming), Spartacus Gladiator of Rome (WMS), Bruce Lee (WMS)


Crime has been a popular slot machine theme since the first online slots appeared. Microgaming's Cops 'n Robbers slot featured a policeman on the hunt for a dastardly robber. The game is still popular today and has even spawned a sequel.

More recently, BetSoft has released 3D crime-themed slots like After Night Falls and The Slotfather, complete with immersive video sequences and big jackpots.

The '80s retro theme runs through more recent games like Hotline and Neon Staxx, both from NetEnt. Hit expanding wilds and free spins and you make your way through the multi-level bonuses.

Recommended Slots: Jack Hammer (NetEnt), Jack Hammer 2 (NetEnt), Hotline (NetEnt)


Relive your favorite rock bands and musicians with a music-themed slot. Music-themed games have been hugely popular in land-based casinos, but many titles have made their way to the online casino.

PA-licensed NetEnt has released a whole series of online slots based on popular rock bands. Enjoy actual live footage of artists like Jimi Hendrix, Guns N' Rose and Motorhead in NetEnt's branded slots. The games feature trademarked imagery and sound clips - the perfect combination for music fans everywhere.

Recommended Slots: Guns N' Roses (NetEnt), Motorhead (NetEnt), Jimi Hendrix (NetEnt)


Everyone loves to be scared once in a while. Horror has been one of the most popular slot themes for developers over the years.

From Playtech's Full Moon Fortunes with its werewolf theme to Microgaming's vampire-themed Immortal Romance, developers love nothing more than to shock players.

In Blood Suckers and Blood Suckers II, NetEnt have produced two of the best-paying online slots in the world. Enjoy free spins, a hidden treasure bonus round and random features like the Bonus Shot.

Recommended Slots: Blood Suckers (NetEnt), Blood Suckers II (NetEnt), The Invisible Man (NetEnt)

Gems & Jewels

Jewels have long been a common feature of slots. More recent examples include Twin Spin and Dazzle Me from NetEnt, and the legendary Da Vinci Diamonds from IGT.

Da Vinci Diamonds pioneered the Tumbling Reels feature, where winning combinations are removed from the reels to give players the chance of hitting further winners.

Why are diamonds so popular in themed slot machines? Perhaps slots developers just want to give the player an idea of what he or she can buy with a jackpot.

Recommended Slots: Twin Spin (NetEnt), Dazzle Me (NetEnt), Triple Diamond (IGT), Da Vinci Diamonds (IGT)


The very first slot machines featured fruit symbols. Instead of cash, you would win flavored chewing gum according to the fruit symbols appearing on a payline.

The fruit theme is still a hit with developers and players today. Fruit-themed classic slots often feature just a few paylines and go light on bonus features. Try NetEnt's Grand Spinn with multiplier wilds, nudge feature and three big jackpots.

Recommended Slots: Grand Spinn (NetEnt), Double Ruby (Everi), Triple Red Hot 7s (IGT), Neon Reels (iSoftBet)

Games & Gameshows

Are you missing your favorite gameshow or board game? Branded games have long been popular among themed slot machines players.

Barcrest and WMS have both released a range of slots based on the popular board game, MONOPOLY. Enjoy locked wilds and a progressive multiplier for big wins, or lock in dancing wilds for added payouts.

Or try IGT's Jeopardy! Slot machine, based on the hit TV game show. Land a screen of wild symbols to earn the jackpot.

Recommended Slots: MONOPOLY Mega Movers (WMS), MONOPOLY Big Event (Barcrest), Wheel of Fortune (IGT)

Fantasy & Magic

The fantasy genre is one that lends itself well to online slots. Take a trip into a fantasy world and take on mythical beasts to win the jackpot. Or, join a wizard or witch and conjure up potions that will turn into big-paying prizes.

NetEnt's high-volatility Conan slot is played on 6 reels and features a pay-both-ways set-up. The game has mystery symbols with mystery multipliers. If a reel appears stacked, Conan leaps into action to battle a mighty monster for the chance of winning a big jackpot.

Recommended Slots: Magic Portals (NetEnt), Beowulf (Quickspin), Conan (NetEnt)

Fairies & Fairytales

From fantasy to fairies. Although fairytales are popular with children, they're also a big deal for slot developers.

From the beautiful Pixies of the Forest from IGT to NetEnt's Jack and the Beanstalk, fairytales have proven furtive ground for software manufacturers.

Fairytale-themed slots also tend to feature amazing graphics and interesting bonuses. Check out NetEnt's Fairytale Legends: Hansel and Gretel with stacked wild re-spins, free spins and thrilling random features.

Recommended Slots: Fairytale Legends: Hansel and Gretel (NetEnt), Jack and the Beanstalk (NetEnt), Pixies of the Forest (IGT)


Making money is the aim of every slot, but sometimes money becomes the theme. Money-themed slots feature bank notes, gold bars and bank vaults just waiting to be broken into.

AGS Interactive's Rakin' Bacon is a money-themed online slot featuring high-paying gold rings and bars. The game also features four progressive jackpots that pay out enough money for you to set up your own private vault.

Recommended Slots: Rakin' Bacon (AGS Interactive), Mr Cashback (Playtech)

CHECK OUT: What Is A Progressive Slot?


Who can resist a cute cat or a mighty tiger when they play slots? Animals form the backbone of popular online slots from Mega Moolah and Raging Rhino to AGS Interactive's Longhorn Jackpots.

Typically, the fiercer the creature, the higher the payout. Find stacked rhinos in WMS's hit Raging Rhino slot or land the lions in Mega Moolah for a big-money jackpot.

The trademarks of a good animal-themed slot are great graphics, animation and great bonuses. Go on the hunt yourself for the best themed slot machines.

Recommended Slots: Double Wolf (Everi), Mega Moolah (Microgaming), White Orchid (IGT), Raging Rhino (WMS)

TV & Movies

Branded slot machines don't just focus on music. You will also find plenty of games based on hit films and TV shows. Many branded TV and movie slots start life in the land-based casino, but you can now find plenty of games adapted specially for online casinos.

The biggest tie-in slots, such as Microgaming's Bridesmaids, feature actual images and video sequences from the source film. WMS's Friends slot was many years in the making, but it features a series of bonus rounds based on the show's best moments.

Recommended Slots: Jumanji (NetEnt), Friends (WMS), Terminator 2 (Microgaming)

Greek Mythology

Who can resist a trip to Mount Olympus for a slots party with Zeus, Aphrodite and Poseidon? Greek myths are a rich vein of inspiration for slots developers: mythical creatures, powerful gods, and magical weapons all play a part in games like Zeus III and IGT's Golden Goddess.

And don't forget Playtech's awesome Age of the Gods slots. These myth-themed games form part of a larger range of progressive slots, each with its own unique bonus features.

Recommended Slots: Golden Goddess (High 5 Games), Zeus III (WMS), Olympus Strikes (AGS Interactive)

Norse Mythology

From Greek mythology to Norse myths. Microgaming's classic Thunderstruck slot introduced online gamblers to the mighty Thor, the god of thunder.

Since then, Norse mythology has proven to be one of the best slot machine themes. Scandinavian giants, NetEnt, are the masters of the genre, with games like Asgardian Stones featuring Colossal symbols that provide even bigger winning combinations.

Recommended Slots: Asgardian Stones (NetEnt), Thunderstruck II (Microgaming)


Mexican-themed slots have been a popular addition to online casinos in recent years. Titles like Spinata Grande and Play'n GO's Grim Muerto are packed with color and iconic imagery from Mexican festivals.

If you're looking for themed slot machines with lots of hot chili action, authentic Mexican music and a lot of great images, check out some Mexican-themed slots.

Recommended Slots: Spinata Grande (NetEnt), Chili Chili Fire (Konami)


For years, Barcrest was the master of the Irish-themed slot. Its Rainbow Riches slots set the benchmark for Irish-themed games, complete with leprechauns, pots of gold and Celtic music.

Other developers have jumped on the Irish bandwagon, such as NetEnt with their Finn's Golden Tavern slot. But for high-volatility Irish-themed slots fun, look no further than Rainbow Riches and its many sequels.

Recommended Slots: Finn and the Swirly Spin (NetEnt), Rainbow Riches Pick 'n Mix (WMS), Rainbow Riches (Barcrest)


Ancient Egypt has been a popular source of material for video slots developers over the years. IGT's Cleopatra game - and the progressive slot follow-up - MegaJackpots Cleopatra - are two of the best, but look out too for Crown of Egypt, also from IGT.

Recommended Slots: Crown of Egypt (IGT), Cleopatra (IGT)

Wild West

Take a trip back in time to a world of desperados, gunslingers and frontier towns. The Wild West and the Gold Rush have inspired dozens of online slots, but who doesn't want to strike it rich?

Check out NetEnt's 3D Dead or Alive slot, or go for gold in BetSoft's Boom Brothers. Both games boast animated graphics and a host of explosive bonus features.

Recommended Slots: Dead or Alive (NetEnt), Wild Wild West (NetEnt)


Blast off into outer space with a selection of science fiction slots. Take on alien cows in WMS's Invaders from the Planet Moolah or become one with the stars in Starmania or Starburst.

Sci-fi is one of the most enduring slot machine themes around.

Recommended Games: Drive Multiplier Mayhem (NetEnt), Elements: The Awakening (NetEnt), Starmania (NextGen)

Where Can I Find Themed Slots?

Looking for themed slot machines online? In 2020, you can play hundreds of legit online slots at the best casinos in Pennsylvania. Whether you are looking for a Greek mythology-themed bonus slot or an animal-themed progressive, we have it covered.

Check out our list of the best online slots right here at PennStakes.com. Often, you can play real-money games online that you just won't find in your local casino, or even one in Pittsburgh or Philadelphia. Play for a few cents or hit the max bet button and try to win the progressive jackpot.

And when you play online slots, you can claim a super casino bonus just by signing up. Make a first deposit and earn free spins on your favorite games. It's like winning free money just for doing the thing you love most.

You'll find a list of top PA online casinos right here. Read our reviews and discover the best slots bonuses for casino players in our state.



Jon Young is a writer & magazine editor with over 12 years' experience in the gaming sector. He has written on everything from poker, slots, mobile gambling, sportsbooks & online casinos in Pennsylvania. When not trying to take down the Mega Moolah jackpot he can be found playing poker tournaments in casinos.

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