If necessity is the mother of invention, the challenge must have fathered innovation because game makers are always challenging themselves to come up with the craziest, most innovative concepts for the slots they create.

This continuous drive to create new and engaging online games is the secret behind so many legendary games that we all love to play. The theme of the slot is one aspect of the game where developers let their creativity run wild, and rightly so. I, for one, love to discover slots by theme. My favorite ones are the pirate-themed slots (like Dead Man’s Trail or 9 Skulls of Gold) and the adventure ones (like Gonzo’s Quest). But there’s surely something for everyone because the list of slot themes is (almost) endless.

You may be asking yourself, why would I want to play slots by theme? There may be no reason, or perhaps you are drawn to a particular category of slots because you are a fan of the theme. Many players choose a theme because they feel a personal connection with it.

Listed below are some of the most popular types of themes that have been used for online slots.

• Christmas Slots - It’s always the season to be jolly with Xmas-themed slots! Games like Big Bad Wolf Christmas Special, Aloha! Christmas, 9 Gifts of Christmas, Big Bass Christmas Bash, Christmas Big Bass Bonanza, Christmas Carol Megaways, Ding Dong Christmas Bells, and Fishin’ Frenzy Christmas will give you Christmas cheer all year round!
• Ancient Egypt Slots – This is one of those themes that remains ageless. Many titles with an Ancient Egyptian theme come to mind, but probably the most famous in this category is Book of Dead, a slot by Play’n GO that has become one of the legends of the industry. Others I really dig are the Eye of Horus, Light of Ra, Hand of Anubis, Curse of the Mummies, and 4 Secret Pyramids.
• Greek Mythology Slots - The mythical stories from one of the world’s most influential cultures have supplied game developers with an endless source of subject matter that fits perfectly with modern slots. Try Zeus, Gates of Olympus, Legacy of the Gods, Helios Fury, Book of 99, Gods of Troy, Gods of Olympus, slots in the Age of the Gods series or Gates of Troy for starters.

• Fairytale Slots – For sure, fairytale-themed slots are some of the most popular around. The power of the stories we all grew up with and knew so well seems to fit perfectly into the virtual world of online gambling. Games like Adventures Beyond Wonderland, Big Bad Wolf: Pigs of Steel, Big Bad Wolf, Fairytale Legends: Red Riding Hood, Fairytale Legends: Hansel and Gretel, Fairest of them All, Beauty and the Beast, 9 Enchanted Beans, and Jack and the Beanstalk capture the essence of the original stories while offering players the chance to win real-money prizes.
• Safari Slots – The African theme has gained popularity with slots like Safari Sun, Mega Moolah, Wild Herd, King of Cats, Great Rhino Megaways, Gator Gold Gigablox, Safari King, Savanna Stampede and Serengeti Wilds. This is a fun theme that allows game developers to incorporate unique sounds and visuals into their games.
• Comic Slots – Those who love superheroes and other comic characters will have a blast playing slots like Wonder Woman, Batman, Inspector Gadget, Rick and Morty, Minions, Superman and many more!
• Sports Slots – The game is on! Slots like Football Star, Hugo Goal, Break Away, Break Away Lucky Wilds and Basketball Star pack all the adrenalin of the stadium onto the reels of these fantastic examples of games with a sports theme.
• Football Slots - Among all the sports-themed slots online, slots with a football theme are the most popular. Some of the best are Football Finals X UP, Football Glory, D10S Maradona.
• Movie and TV Slots – Taking inspiration from popular movies and TV shows like The Goonies, Gremlins, Rambo, Game of Thrones, The Matrix, Narcos, Gordon Ramsay: Hell's Kitchen and Battlestar Galactica, game makers have gifted us with great looking slots that stay true to the essence of each movie or tv show they represent. Most of these games are trademarked, and feature visuals are taken straight from the source material.
• Bonanza Slots – With games like Bonanza by BTG and Sweet Bonanza by Pragmatic Play, there's little to say about this category of slots. These are games that have disrupted the gaming industry and still enjoy a huge following.

• Aztec, Mayan, and Inca Slots – This theme is another one that’s full of mystery and wonder and makes for an amazing backdrop for slots. Games like Gemstone of Aztec, Fortunes of Aztec, Incan Adventure, 4 Masks of Inca, Mayan Waterfalls, Legacy of Inca, John Hunter and the Mayan Gods, Mayan Multi Mayhem, Book of Aztec, Aztec Falls, and Rich Wilde and the Aztec Idols are a lot of fun to play!
• American Slots – The true American spirit fills the reels of slots like Land Of The Free by Nolimit City or American Gold Fever by Games Global. Slots with an American theme focus on historical and cultural elements that resonate with the right audience. Some add a humorous twist for an extra dose of fun.   
• Wild Slots – There are untameable beasts lurking on the reels of wild-themed slots – buffalos and bison, dinosaurs and wild horses. Play at your own peril!
• Treasure Slots – The quest for finding long-lost treasures is a common theme in movies, literature, and also in slots. Whether it’s sunken, buried or hidden away in some secretive place, you will have the time of your life looking for it in slots like Treasures of Troy, Octopus Treasure, Mystic Panther Treasures of the Wild, Legendary Treasures, Jin Ji Bao Xi Endless Treasure and Da Vinci's Treasure.
• Viking Slots – For people who didn’t leave much behind in terms of recorded history, these seafaring folk surely did leave their mark. Book of Vikings, Vikings Go Berzerk, Vikings Go To Valhalla, Viking Gods: Thor & Loki, Viking Queen, Ring of Odin, Odin's Riches, Odin: Protector of Realms, and Valhalla Saga: Thunder of Thor are but a few of the vast number of games with a Viking or Norse-mythology theme.
• Halloween Slots – Ghouls, vampires, witches and all sorts of creepy monsters take center stage in slots inspired by the Halloween celebration. Here are some of my favorite slots in this category: Immortal Romance, Castle of Terror, Book of Shadows, Jack O’Lantern Mystery Mirror, Joker Lanterns Hold and Win, Tricks and Treats, Full Moon Fever, and Nightmare Family Megaways.
• Asian Slots – Games with an oriental theme focus on cultural aspects that many Westerners find fascinating. These include elements from nature, such as the cherry blossoms, the history, such as legends of samurai, and oriental concepts about luck and wealth. Try Thai Blossoms, Sakura Fortune and Sakura Fortune 2, Sakura Dragon, Royal Dragon Infinity Reels, Fortune Dragon, Power of Asia, Moon Princess, or Koi Princess to get a taste of the Orient.
• Wild West Slots – Dead or Alive, Dead or Alive 2, Magnificent 7, Wild Wild West: The Great Train Heist, Wild West Gold Megaways, Wild West Duels, Deadwood, Money Train, Tombstone R.I.P

• Game Show Slots – Big shows that have kept families glued to their TV screens for years turn out to be great material on which to base real money slots. Some of the best examples in this category are Who Wants to be a Millionaire, Millionaire Mystery Box, Millionaire Rush Megaways, Deal or No Deal and Wheel of Fortune.
• Pirate Slots – Ahoy mate! Hoist the black flag and get ready to plunder on the reels of pirate-themed slots like Cursed Seas, Pirates’ Plenty Megaways, 9 Skulls of Gold, Pirate Golden Age, Dead Man’s Gold, Dead Man’s Trail, and Pirate Sharky!
• Fishing Slots – Casting a line for a chance to catch the big fish has never been so exciting! Fishin’ Frenzy, Big Bass Bonanza, Fish’n’Nudge, Bigger Bass Blizzard, Big Bass Amazon Xtreme, 4 Fantastic Lobsters and other fishing-themed slots can give you hours of fun, just like the real thing. 
• Music Slots – Game developers and the music industry teamed up to create branded slots that pack impressive soundtracks and bonus features taken straight from some of the most popular music acts. Have a listen to Alice Cooper and the Tome of Madness, Helloween, Elvis the King Lives, Danger High Voltage, Punk Rocker, Top Dawgs, The Final Countdown, Motörhead, Guns N' Roses, Jimi Hendrix, Ozzy Osbourne, Disco Danny or Dirty Dancing and get in the groove!
• Adventure Slots – This is a theme I really love since the slots here are usually full of captivating bonus features that add layers of fun to the playing experience. Some of the best slots with an adventure theme are Rich Wilde and the Tome of Madness, Rich Wilde and the Wandering City, Rich Wilde and The Shield of Athena, Rich Wilde and the Amulet of Dead, Return of the Green Knight, Gonzo’s Quest, Gonzo’s Gold, John Hunter and the Quest for Bermuda Riches, and John Hunter and the Tomb of the Scarab Queen. There are more, of course, so check out my page dedicated to Adventure Slots and see if you can pick out a favorite.
• Magic Slots - The Magic Cauldron - Enchanted Brew, The Magic Orb, Magician's Secret, Fire Blaze: Green Wizard, Fire Blaze: Blue Wizard, Wizard of Gems, 3 Lucky Witches, Witches Riches, Magikspell, Arctic Enchantress
• Alien and Space Slots – Reactoonz, Gargantoonz, Alien Robots, Cowboys and Aliens, Space MIners, Spaceman, Space Wars 2 Powerpoints, Space Battle, Retro Galaxy, Stars of Orion
• Fruit and Sweets Slots – Fruits have decorated the reels of slot machines since the very beginning. When slots made the shift from land-based casinos to online, fruits were also among the first symbols to be used in slots, together with all sorts of candies. There’s something nostalgic about fruit-themed or sweet-themed slots that makes them super fun to play. Get a taste of Stars n' Sweets Hold & Win, Candy Stars, Sweet Bonanza, Hansel & Gretel Candyhouse, Fruit vs Candy, Don’t Eat the Candy, Candy Paradise, Candy Jar Clusters, Candy Blitz, or Jammin' Jars, and you’ll see what I mean.
• Gem Slots – Gems are one of the oldest themes when it comes to slots. Developers continue to use them as symbols on modern slots to this day. If you like glinting precious stones, then here are some gem-themed slots to look out for Sizzling Gems, Dream Drop Diamonds, Gem Crush, Frozen Diamonds, Joker Gems, GEMiX, Gems Infinity Reels, Divine Diamonds, Gems Bonanza, Diamond Cascade, and Prism of Gems.
• Irish Slots – If someone asks me to name a symbol of luck, the first one that comes to mind would be the shamrock, and the second the leprechaun. Both are Irish, and you can find them in all Irish luck-themed slots such as Rainbow Riches, 9 Pots of Gold, Shamrock Money Pot, Irish Eyes, Shamrock Holmes Megaways, Rainbow Riches Power Mix, Shamrock Miner, Leprechaun’s Vault, Leprechaun's Magic Megaways, and Lucky Leprechaun Clusters.
• Rainbow Riches Slots – The Rainbow Riches slot series contains popular games known for their colorful graphics, simple but fun gameplay, and unconventional bonus features which vary from game to game. Rainbow Riches Reels of Gold or Rainbow Riches Power Mix come with a unique layout, while Rainbow Riches Megaways uses the Megaways engine developed by Big Time Gaming to boost the ways to win up to 117,649 on every spin.
• Bizarre Slot Themes – While most game providers focus on themes that can be called mainstream, developers like No Limit City and Hacksaw Gaming have taken a different route. With titles like Punk Toilet, Benny the Beer, Mental, Densho, San Quentin xWays and Das xBoot, the two game makers challenge the industry by tackling sensitive topics in an unusual, often humoristic (and very artistic) way.
• Animal Slots – Buffalos and wolves, mustangs and cats, dogs, bunnies, and crazy chickens make for noisy but fun-filled online animal slots! Step into a virtual real money zoo with games like The Dog House Megaways, Big Bad Wolf Megaways or Buffalo Blitz II.
• 777 Slots – The slots bearing the 7 symbols so commonly associated with luck all offer straightforward gameplay with simple mechanics. This lets you focus on the fun aspect of the games, some of which have become cult classics, like Fire Joker and 9 Pots of Gold Megaways.

The online casinos in the list that follows have all been carefully reviewed to ensure they provide a fair and secure gaming environment. For each one, I've checked the licenses, payment options, responsible gambling measures, terms for bonuses and promotions, as well as the games being offered. All of them have great selections of slots with themes, so take your pick and enjoy playing.

Online video slots provide the best canvas for game makers to unleash their creativity. They do so by exploring a wide range of slot themes, creating visuals and bonus features around these themes, and, of course, offering a great experience to the players.

As you can see from the list above, the range of slot themes is quite large, and there’s no limit to where the imagination can take the creative minds behind these games. And my list is far from exhaustive. There are dozens of other themes that I have not covered.

Online casino software providers look everywhere for inspiration. Developers buy the rights to develop games from movie franchises, music acts, TV shows, comic books, and even famous people such as Joe Exotic. The available technology enables them to create awesomeness, which is why, whether it’s an adaptation of a movie, TV series, or game show, a slot inspired by a long-lost civilization, or your favorite rock band, you can expect new themed slots to look and feel great.