Slot WIKI Slot Wiki

Betting 1, 3, 2, then 6 units in order as you keep winning.

Versions in which Pragmatic Play relaunched popular games with much bigger multipliers and max wins. "1000" is added to the end of the name, and a signature trait is multiplier symbols that can reach up to 1,000x.

A game company that started in the UK in 2002 with a virtual football game. Based in Brighton, it supplies 750+ slots from studios including 1X2gaming and Iron Dog Studio, along with virtual sports, table games and arcade games.

A casino game company that launched in the US in 2005 as "American Gaming Systems." It started with Class II slots for Native American tribal casinos, then expanded into slots, table games, and online games, and is best known for the "Rakin' Bacon" series.

A setup where the player can choose how many lines to activate.

A slot machine company that Aristocrat founder Len Ainsworth started anew in Australia in 1995. It is listed on the Australian Securities Exchange, and Austria's Novomatic is its largest shareholder. Novomatic's attempt to acquire it outright in 2025-2026 fell through.

This is the online gambling regulator of Alderney, a small island in the English Channel. Founded in 2000, it is considered a costly but trusted "whitelist" jurisdiction, with annual fees by revenue tier and a requirement to host servers locally.

A gaming machine company founded in Austria in 1993. It is headquartered in Rutzenmoos in northern Austria, builds slot cabinets, multiplayer systems, and jackpot and casino management systems, and exports 90% of its output.

An online casino license issued in the name of Anjouan, an island in Comoros, Africa. It's cheap and fast, so many new casinos use it, but the Comoros government denies the issuing body's legitimacy, which has caused major controversy.

An option that raises the bet on every spin, usually by about 25%, in exchange for a higher chance of triggering free spins. Wazdan's Double Chance and Nolimit City's xBet belong to the same family.

A global slot machine company that launched in 1953 in Sydney, Australia. It is Australia's largest and one of the world's leading casino machine makers, behind signature slot series like Buffalo, Lightning Link, and Dragon Link.

A theme of lucky symbols like dragons, fortune characters, wealth gods, and koi.

A feature that spins automatically for a set number of times.

NetEnt's name for winning symbols breaking and new symbols dropping from above.

A slot studio founded in Malta in 2018 that created the "PopWins" mechanic, where winning symbols pop and split in two, making the reels grow. Known for "-Pop" games like CherryPop and PopRocks, and for Floridaman.

A theme built around ancient Latin American ruins and gold.

A slot provider that started as the game development team at SOFTSWISS and became independent under the BGaming brand in 2018. It was early to adopt cryptocurrency payments and provably fair games, and the Elvis Frog series is its signature work.

A game testing lab that launched in 1981 in Las Vegas, USA, and describes itself as "the oldest private independent gaming test lab." It tests slots, RNGs, online games, and lotteries, and is recognized in more than 480 jurisdictions.

All the money you have set aside specifically for gambling.

A collection of terms for managing your gambling funds and protecting yourself, such as bankroll, loss limit, win goal, chasing losses, tilt, deposit limit, and self-exclusion.

The normal spin state outside of any bonus.

A big win that comes from the base game rather than a bonus.

A single place for the basic terms used in every slot, such as reels, paylines, ways, bet level and autoplay.

It is Belgium's gambling regulator. Belgium is one of Europe's strictest countries, with a minimum age of 21 for all gambling, a 200 euro weekly deposit limit, a bonus ban and an advertising ban.

A setting that determines how many coins you bet per line.

A slot provider founded in 1999 that made its name in 2006 with its cinematic 3D "Slots3" series. Headquartered in Valletta, Malta, it has recently been releasing "Hold & Win" slots steadily.

A collection of rules that change your bet size after wins and losses, such as Martingale, Paroli, d'Alembert, Fibonacci, and the Kelly criterion. It also explains why no system can change the house edge.

The standard amount for a single bet, set as a share of your bankroll.

A slot provider founded in Sydney, Australia in 2011, and the company that created Megaways. It scored hits like Bonanza and Extra Chilli, and was acquired by Evolution in 2021 for up to 450 million euros.

The presentation that usually appears on wins of about 10-20x the bet or more.

An empty space with no picture. Mostly used in classic slots to adjust win probability.

A slot provider launched in the UK in 2001, and part of Germany's Gauselmann Group (Merkur) since 2008. It's known for the Fishin' Frenzy series, its progressive jackpot "Jackpot King", and its early adoption of Megaways.

Content where several people each open a bonus and compare results.

A feature that lets you pay a set multiple of your bet to jump straight into free spins or a bonus round. Also called feature buy, and banned in the UK since 2019.

The deadline for meeting the bonus and wagering conditions.

A collection of slot bonus features sorted by type, including free spins, respins, Hold & Spin, tumbles, multipliers and bonus buy.

A value showing how many spins, on average, it takes for a bonus feature like free spins to trigger once. "1/150" means once every 150 spins on average, and it matters for understanding volatility and bonus buy prices.

Content where bonuses are collected across several games and opened all at once.

The share of the RTP that comes from bonus features.

A dedicated symbol that starts a bonus game or special feature.

A genre where the book symbol doubles as wild and scatter and an expanding symbol appears during free spins.

A slot provider launched on the Isle of Man in 2014. It makes a wide range of HTML5 slots, from classic fruit slots to noir themes, with teams in Malta, the UK, Germany, Poland, Romania and more.

A slot provider launched in 2015. It's known for "Hold & Win" jackpot slots, and in 2021 it spun off its regulated-market business as "3 Oaks Gaming". The BNG brand operates under a Curaçao license.

A win type that pays from the right as well as from the left.

Slots that use real brands such as movies, TV shows, musicians, and games.

It is the betting and online gaming regulator under Brazil's Ministry of Finance. The regulated market opened on January 1, 2025, with more than 80 brands licensed in the first year, and Brazil has emerged as one of the world's largest online slot markets.

The mindset of treating winnings as not really your own money and betting them again too easily.

An Asian provider that launched in Taipei, Taiwan in 2016. It's known for slots as well as multiplayer fishing games, and all of its games are GLI certified.

A bright theme with candy, jelly, and cake symbols.

Money you can withdraw right away versus bonus money that still has conditions attached.

Playtech's money symbol collection feature brand.

A promotion that returns part of the amount you lost over a set period.

A collection of terms used in online casino bonuses and their conditions, such as welcome bonus, deposit bonus, no-deposit bonus, cashback, wagering requirement, game contribution, and max cashout.

The casino's cashier window that handles chip exchange and cash services.

A token used in place of cash inside a casino.

The main area of a casino where the game tables and slot machines are.

A collection of the game types you can find in online casinos besides slots. It covers turbo games like Crash, Plinko, and Mines, draw-style games like Keno, Bingo, and fishing games, plus RNG table games, live dealer games, game shows, and video poker.

A staff member dedicated to regular and high-stakes customers who looks after their perks.

South Korea has 17 government-licensed casinos. Of these, 16 are for foreigners only, and Kangwon Land in Jeongseon, Gangwon Province is the only one Korean citizens can legally use. All unlicensed online casinos are illegal.

Betting bigger and playing longer to try to win back what you lost.

An old-style 3-reel slot with fruit, 7s and BAR symbols.

A win system where, instead of paylines, matching symbols must connect horizontally or vertically in groups of a minimum size (usually 5). It is mostly used together with tumble and on large grids.

The amount of a single coin, which is the unit of betting.

A symbol that gathers and pays out the values of all money symbols on screen.

A system where collecting certain symbols fills a meter and upgrades a feature once it is full.

It is Colombia's agency that manages the state gambling monopoly. In 2017 it issued Latin America's first online casino and betting licenses, and it later became a model for regulation across the region.

Perks a casino gives customers for free, such as rooms and meals.

The probability of the opposite event, such as "never happening even once."

A range likely to contain the true value.

A feature that lets you lock your own account for a day up to several weeks.

The balance you can use inside the game.

An online casino that handles deposits and withdrawals in cryptocurrency.

This is the online gambling license of Curaçao in the Caribbean. It was long known as the easiest license to obtain, but when the new gambling law (LOK) took effect in December 2024, master licenses were abolished and licenses are now issued directly by the government.

Red Tiger's jackpot that is guaranteed to drop within a set time.

When you enter a bonus but it ends with almost no payout.

A spin with no win at all.

A casino employee who runs a table game.

A mode where you play with virtual credits and no real money.

This is the gambling regulator under Denmark's Ministry of Taxation. It opened an online casino market early by European standards in 2012, and in 2025 online casino overtook lotteries to become the most popular form of gambling among Danes.

A bonus given in proportion to the amount you deposit.

A cap on how much money you can deposit per day, week, or month.

Relax Gaming's network progressive jackpot.

Pragmatic Play's network tournament and prize draw promotion.

A stretch where no wins or bonuses show up for a long time.

A structure where two wilds face off and the winner's multiplier applies.

A slot machine manufacturer that launched in Sofia, Bulgaria in 2002. It makes machines widely placed in casinos across Eastern Europe, Latin America, and Africa, and is known for classic fruit slots like 40 Super Hot and Shining Crown and the "Jackpot Cards" mystery jackpot.

A slot studio founded in Stockholm, Sweden in 2012. Known for "X-iter", which lets you pick a game mode and jump straight in, and the Pirots series where birds collect gems.

A theme with pharaoh, pyramid, and scarab symbols.

A slot provider that launched in 2012 in Prague, Czech Republic. Rather than extreme volatility, it focuses on distinctive art, animation, and games that are easy for anyone to enjoy, and it won Product of the Year in 2015 for "Ninja."

The highest level of win presentation.

A Maltese casino and sports betting technology company founded in 2008. It supplies the CasinoEngine game distribution platform and sports betting solutions, and also owns in-house game studios such as Spearhead Studios, Armadillo Studios and Fantasma Games.

The world's largest live casino provider, founded in Sweden in 2006. It created live game shows like Crazy Time and Lightning Roulette, and by acquiring NetEnt, Red Tiger, Big Time Gaming, and Nolimit City it also became a major group in slots.

A slot provider that launched in 2017, headquartered in Limassol, Cyprus, with a development center in Kyiv, Ukraine. It is known for 3D graphics, RPG-style progression structures, and its in-house engine, "Spinential."

Games you cannot play with a bonus or that do not count toward wagering.

A feature where the reel height or grid grows larger during a bonus.

A wild that expands to fill the entire reel when it lands.

The average value you get per try if you repeat a choice countless times. In slots it is calculated as "bet × (RTP - 100%)", and it is almost always negative.

The average loss, calculated as total wagers × house edge.

A slot studio founded in Stockholm, Sweden in 2017. Known for unique mechanics, imaginative themes and high-volatility slots, it was acquired by the platform company EveryMatrix in 2024.

Following the sequence 1, 1, 2, 3, 5, 8 ..., moving to the next number after each loss.

Playtech's respin and jackpot feature brand.

A theme where an angler collects fish money symbols.

A jackpot whose amount is preset as a multiple of your bet.

A setup where all lines are always active and the number of lines cannot be changed.

Betting the same amount every time, regardless of results.

It is France's gambling regulator. The 2010 online gambling law opened only sports betting, horse racing and poker, and online slots and casinos are still banned. France is one of two EU countries that block online casinos.

Free spins an operator grants for use on specific games.

A demo version that lets you spin slots with virtual credits instead of real money. The rules and odds match the real version, so it's used to check a game's structure and volatility without spending anything.

A promotion that gives you a set number of free spins on a specific slot.

The classic slot bonus round, triggered when a certain number of symbols such as scatters land, giving you a set number of spins with no extra bet.

Free spins where the player picks the combination of spin count and multiplier.

A classic theme using cherry, lemon, watermelon, 7, and BAR symbols.

The world's largest gaming test lab, launched in 1989 in New Jersey, USA. It checks whether slot machines and online games meet regulatory standards, and it created industry standard documents such as GLI-11 and GLI-19.

A game provider headquartered in Yerevan, Armenia, and part of the Digitain Group. It makes crash games, quick games, skill games and slots, and has won several awards for crash games with 98%+ RTP such as Tower Rush and Maestro.

A feature where you risk a win, for example by guessing a card color, to try to double it.

The mistaken belief that, in independent events, something that hasn't happened for a while is "due." Every slot spin is independent through the RNG, so previous results do not affect the next spin's probability.

A support service to turn to when you need help with a gambling problem.

The percentage of each bet that counts toward wagering, by game type.

A provider established on the Isle of Man in 2021 that acquired Microgaming's game portfolio and distribution business in 2022. It supplies about 1,300 games from more than 40 dedicated studios and took over the Mega Moolah jackpot.

A London-based game company that holds the rights to "Slingo," a game that combines slots and bingo. After acquiring Slingo in 2015, it creates Slingo games combined with popular slot brands and licenses them to many casinos.

A slot provider founded in Berlin, Germany in 2008. It started out making games for German land-based gaming halls, then moved online, and is best known for German-style classic slots like Ramses Book and Crystal Ball.

A collection of general casino terms such as dealer, pit boss, high roller, junket, VIP room, casino chip, rolling chip, comp, and marker.

This gambling regulator was created jointly by Germany's 16 states. It legalized online slots in July 2021, but its rules are among the strictest in the world: a 1 euro bet per spin, a 5-second gap between spins, and a 1,000 euro monthly deposit limit.

An online gambling license from the British territory of Gibraltar, at the southern tip of the Iberian Peninsula. Major betting and casino companies are based there, and a new gambling law took effect in October 2025.

A slot mechanic made by Yggdrasil. Giant symbols from 2x2 to 4x4, and up to 6x6 in some games, land on the reels and split into single symbols, one per cell, when wins are counted.

A variant that adds one extra unit on top of doubling, to increase profit when recovering losses.

Greece's gambling regulator. Under the new online gambling law (4635/2019), it issues separate betting and casino licenses with 7-year terms, while part of state-owned OPAP's monopoly remains.

A theme featuring Zeus, Poseidon, and Medusa.

All the cells on a slot screen, made up of reels and rows.

A format where entering the jackpot feature always wins a jackpot at some tier.

A slot and table game supplier that launched in 2012. It's known for its in-house math models and sound design, and in 2025 it won licenses in Brazil, Denmark, and Greece in quick succession, expanding to more than 24 jurisdictions.

A provider that started with scratch cards in 2018 and shifted to slots in 2019. It grew rapidly with Wanted Dead Or a Wild and Chaos Crew, and listed on Nasdaq Stockholm in 2025 at a valuation of about 2 billion euros.

Random numbers drawn from physical phenomena such as electrical noise.

A customer who bets very large amounts.

A symbol with a high payout that appears rarely. Usually game characters or themed pictures.

The history of slot machines, from the mechanical "Liberty Bell" in 1890s San Francisco through electromechanical slots, video slots, virtual reels, online casinos, Megaways, and mobile slots.

The share of all spins that produce a win, regardless of the amount. A 25% hit rate means a win about once every 4 spins on average, and it is a separate concept from RTP.

A bonus that locks money symbols in place and respins; the spin count resets whenever a new symbol lands.

A bonus where landing a certain number of money symbols locks them in place and starts respins, with the respin count resetting each time a new symbol lands. Also known as Hold & Win or money respins.

The share of money wagered that the casino actually keeps.

A dark theme featuring zombies, vampires, and monsters.

A Las Vegas-style classic theme with 7, flame, and star symbols.

The share of wagers the game operator is designed to keep over the long run. In slots it is 100% minus the RTP, so an RTP of 96.5% means a house edge of 3.5%.

A guide to the numbers and information to check when choosing a slot. It covers how to read RTP, volatility, max win, hit frequency, bonus frequency, and bet range against your budget and goals, and the order for checking them in a demo first.

A fast play mode introduced by Pragmatic Play. It skips the reel animation and shows results right away, provides a history of past spins and replays, and the RTP stays the same.

A global casino gaming machine company founded in the US in 1975. It created Megabucks, Wheel of Fortune, and Cleopatra, and in 2025 Apollo acquired its gaming and digital business and merged it with Everi to form the new IGT.

A feature that gives a reward when you complete a set task.

Events where an earlier result does not affect a later one.

If symbols revealed by xWays are on screen, those symbols expand too.

A slot mechanic created by ReelPlay of Australia. Each time the rightmost reel is part of a win, a new reel is added, and the multiplier goes up with every extra reel.

A gaming technology company known for gaming machines in UK betting shops and pubs and for "virtual sports." Headquartered in New York and listed on Nasdaq, it supplies server-based gaming machines, virtual sports, and online slots.

This is the gambling regulator of the Isle of Man, a Crown Dependency between Britain and Ireland. Founded in 1962, its 2001 online gambling law and low gambling duty (up to 1.5%) have attracted major companies like Microgaming and Playtech.

Italy's Customs and Monopolies Agency oversees gambling regulation. It legalized online slots in 2011, and in November 2025 it introduced a new system with a 7 million euro license fee, a 9-year term and one site per license. It is the second-largest online market in Europe after the UK.

The share of each bet that goes into the jackpot pool.

A collection of slot jackpot types and related terms, such as fixed jackpots, progressive jackpots, wide-area jackpots, and must-drop jackpots.

A symbol labeled with a jackpot name such as Mini, Major or Grand.

A theme featuring samurai, ninjas, and maneki-neko.

A business that gathers VIP customers, brings them to a casino, and earns a commission.

The process of verifying a player's identity and age.

This is the gambling regulator of Kahnawake, a Mohawk territory in Quebec, Canada. Founded in 1996, it has issued online gambling permits since 1999 based on Indigenous self-governance, making it one of the world's earliest online regulators.

A slot provider launched in 2016 with bases in Malta and Kraków, Poland. It is known for its "HyperBet" feature, which raises your bet to improve bonus chances, and for games like Joker Max and Raging Bull.

A formula that calculates the optimal bet fraction from your win probability and the payout odds.

The casino gaming division of Japan's Konami Group. It started operating in Australia in 1996 and the US in 1997, and builds slot machines and the "SYNKROS" casino management system from its base in Las Vegas.

A commission under the Prime Minister that oversees and manages South Korea's legal gaming industries as a whole. Launched in 2007, it manages industry size through a revenue cap system and monitors illegal online gambling. Legal gaming revenue in 2025 exceeded 26 trillion won.

Building a list of numbers and betting the sum of the two end numbers.

A probability principle stating that as the number of trials grows, the average of actual results gets closer to the theoretical expected value. A slot's RTP only lines up after hundreds of thousands to millions of spins.

The live ranking table of a tournament.

A reward given when your tier rises based on cumulative wagers.

A major casino gaming company based in Las Vegas, USA, formerly known as Scientific Games. It acquired Bally, WMS, and Shuffle Master, and changed its name in 2022 after selling its lottery and sports betting businesses.

The gambling regulator under Lithuania's Ministry of Finance. It legalized online gambling in 2016, raised the gambling age to 21 in 2025, and has announced a full advertising ban for 2028, tightening regulation quickly.

A jackpot that builds up only within a single game or a single casino.

The amount you decide in advance that, once lost, means you stop no matter what.

A result presented like a win even though it pays less than the bet.

A symbol with a low payout that appears often. Usually card letters like A, K, Q, J and 10.

A system that gives points and tier perks the more you bet.

The gaming regulator of EU member state Malta. Launched in 2001, it licenses many slot providers, including Pragmatic Play, Nolimit City, and Play'n GO.

A credit line a casino lends to a customer.

Doubling your bet after every loss so that a single win recovers all earlier losses.

The maximum amount you can bet per spin or round while using a bonus.

The maximum amount you can withdraw from winnings made with a bonus.

The upper limit of what can be won in a single spin or bonus round. It is usually shown as a multiple of the total bet, such as "up to 5,000x," and in many games the round ends immediately once it is reached.

Max win is the cap set by the game's rules, while a jackpot is a separate prize.

Microgaming's flagship progressive jackpot slot.

A win presentation one level above Big Win.

A large symbol that takes up several positions, such as 2×2 or 3×3.

A structure where symbols used in a cluster win split into four smaller symbols.

A patented slot mechanic created by Australia's Big Time Gaming (BTG). The reel heights change on every spin, so the number of ways to win can grow up to 117,649.

A gaming company founded in Germany in 1957 by Paul Gauselmann, renamed from "Gauselmann Group" to "Merkur Group" in 2024. It makes German arcade gaming machines, operates about 800 Merkur arcades, and also supplies online slots.

This is the gambling regulator of the U.S. state of Michigan. It launched online casino and sports betting at the same time in January 2021, and with $3.1 billion in online casino revenue in 2025, Michigan became one of the largest markets in the U.S.

Launched on the Isle of Man in 1994, it is the pioneer of online casino software. It's best known for the Guinness World Record-setting Mega Moolah jackpot, and in 2022 it transferred its games business to "Games Global".

The smallest and largest amounts you can bet in a game.

A mechanic where money symbols showing cash values appear on screen, and when a collector symbol (such as the fisherman) lands too, all those values are gathered and paid out. The Big Bass series and Fishing Frenzy are the best-known examples.

A symbol that shows a value as a multiple of your bet.

A method of finding probabilities and averages by repeating a random experiment on a computer countless times. Slot providers and testing labs use billions of virtual spins to verify RTP and volatility.

The probability that all independent events occur is the product of each probability.

A number that multiplies your win, such as 2x, 10x, or 100x. There are several types, including multiplier symbols, multiplier wilds, progressive multipliers, and position multipliers, and they are the key to max wins worth tens of thousands of times your bet.

A wild that multiplies the win when it is part of a winning combination.

A symbol showing a number that multiplies the win.

A jackpot guaranteed to drop before a set time or amount is reached.

A random reward whose contents are unknown in advance.

A feature where all mystery symbols are revealed as the same symbol at once.

A symbol that all turn into the same random symbol once the spin ends.

A result that stops just one position short of a win.

Launched in Stockholm, Sweden in 1996, it is a pioneer of online slots. It created Starburst, Gonzo's Quest and Mega Fortune, and was acquired by Evolution in 2020 for about 19.6 billion SEK.

It is the Netherlands' gambling regulator. The online casino market opened in October 2021, but after deposit limits and tax increases, an analysis found the illegal market grew larger than the legal one in the first half of 2025.

This is the gambling regulator of Nevada, the U.S. state home to Las Vegas. Founded in 1955, it oversaw record Nevada casino revenue of $15.8 billion in 2025, the fifth straight year of records. Online casino is still not allowed.

This is the gambling enforcement agency of the US state of New Jersey. It opened the first full-scale online casino market in the US in November 2013, and in 2025 online casino revenue ($2.91 billion) surpassed land-based casinos for the first time.

A small bonus given just for signing up, with no deposit required.

A slot provider that started in Stockholm, Sweden. It's known for x-mechanics like xWays and xNudge, dark black-humor themes, and max wins in the tens of thousands of times the bet, and it was acquired by Evolution in 2022.

A theme featuring Thor, Odin, and Vikings.

One of Europe's largest gambling companies, founded in Austria in 1980 by Johann Graf. It both manufactures slot machines and operates casinos and gaming halls, and supplies online slots like "Book of Ra" and "Sizzling Hot" through its subsidiary Greentube.

A feature that shifts a reel by one position to create a win or trigger a bonus.

This is the alcohol and gambling regulator of the Canadian province of Ontario. It opened a private online casino market in April 2022 together with its subsidiary iGaming Ontario (iGO), and online revenue for fiscal 2024-25 was CAD 3.2 billion.

A progressive jackpot network that Pragmatic Play launched in August 2024 exclusively for the Dutch market. It has four jackpot tiers, Mini, Maxi, Mega and Giga, and can only be played at legal Dutch online casinos.

Aiming for just 1 unit of profit per cycle and raising the bet only after wins.

A rare result that lies very far from the average.

A design document laying out a slot's reel setup, win probabilities, and RTP.

A mobile-focused slot provider that launched in 2015. It's especially popular in Asia and Brazil for portrait-orientation games and Asian-themed hits like Mahjong Ways and Fortune Tiger.

A game distribution platform (aggregator) and game studio founded in 2011. Its technology hub is in Sofia, Bulgaria, and after Aspire Global in 2019 and then NeoGames, it now belongs to Aristocrat Interactive.

Doubling your bet after every win, then returning to the starting bet after a set number of wins.

A breakdown of which sizes of wins make up the RTP.

A set line that counts for wins. Matching symbols must connect along that line.

A table listing each symbol's payouts and the game rules.

This is the gambling regulator of the US state of Pennsylvania. It launched online casinos in July 2019, and despite a steep 54% tax rate on online slots, online casino revenue topped $2.7 billion in 2025.

Betting only a fixed percentage (for example, 1%) of your current funds.

It is the Philippines' state-owned gambling company and regulator. In 2025, the Philippine gambling market hit a record 396.1 billion pesos, and online games overtook casino revenue for the first time. The offshore-facing online business (POGO) was banned outright at the end of 2024.

A bonus where you choose from several boxes or items to reveal prizes.

A manager who oversees the pit, an area made up of several tables.

A slot provider headquartered in Växjö, Sweden. It was making mobile games before smartphones existed, and is best known for Book of Dead and Reactoonz. It supplies more than 400 games to over 35 regulated markets.

A Malta-based slot provider founded in 2012. It is known for its "Hold & Win" series such as Buffalo Power and Solar Queen, as well as its "Hit the Bonus" series, and it entered Brazil's regulated market in 2025.

A London-listed gaming technology company founded in Tartu, Estonia in 1999. It covers slots, live casino, poker, bingo, and sports, and is known for the Age of the Gods jackpots and movie-branded slots.

A structure where winning symbols pop and turn into two new symbols, growing the grid.

It is the gambling regulator within Portugal's tourism authority. The 2015 online gambling law led to the first licenses in 2016, and in Q4 2025 casino made up 63% of the 337.6 million euro in online revenue.

The core feature of Pragmatic Play's PowerNudge series. After a win, the winning reels nudge down one position and new symbols drop in to chase consecutive wins, and in free spins the multiplier goes up by 1 with every nudge.

A global game supplier that launched in 2015. It makes slots and live casino games, and holds certifications and licenses in more than 30 jurisdictions, including Malta MGA and UK UKGC.

A format where cash or free spin prizes drop on random spins during play.

A collection of probability and statistics terms you need to understand slot math, such as independent events, probability distribution, expected loss, confidence interval, PAR sheet, loss disguised as win, and pseudo-random numbers.

A table of every possible outcome and its probability.

A jackpot that keeps growing as a portion of each bet is added, until someone wins it.

A multiplier that keeps growing as chains or spins continue.

A method that lets players verify for themselves, using cryptographic hashes, that a game result was not tampered with after the bet was placed. It is mainly used in crypto casino games such as Crash and Dice.

A collection of slot structures named by providers, such as Megaclusters, Infinity Reels, GigaBlox, PopWins, Avalanche, and DuelReels, plus jackpot and reward brands like Daily Drop, Dream Drop, Mega Moolah, and Cash Collect.

Numbers that look random but are produced by a fixed formula.

A slot studio launched in London, UK in 2010. It's known for high volatility hits like Jammin' Jars, Razor Shark and Big Bamboo, and in 2023 LeoVegas, part of MGM Resorts, took a controlling stake.

A slot studio founded in 2011 by three friends in Stockholm. Known for Big Bad Wolf and Sakura Fortune, it still makes its own games independently after being acquired by Playtech in 2016.

The random number generator that decides the result of every slot spin. Each spin is independent of previous results, and testing labs such as GLI, eCOGRA and BMM verify its fairness.

The length before a pseudo-random sequence first repeats.

The starting value from which a pseudo-random generator begins producing numbers.

Blackjack, roulette, and similar games where a random number generator decides results with no dealer.

An early online casino software company launched in Atlanta, US, in 1998. It is known for its "Real Series" slots and progressive jackpots like Aztec's Millions, but some casinos using RTG software have been criticized over payout issues.

A theoretical value showing what percentage of total bets a slot is designed to pay back as winnings over the long run. In Korean it is called 환수율.

Rankings of the official RTP and max win multipliers for the 874 slots in the AI Slot free slot database. It includes the top 20 highest RTP slots, the top 20 highest max win slots, RTP and max win distributions, and a comparison by provider.

A service that collects user play records and shows results per game.

Even for the same slot, a provider may build several RTP levels and let each casino pick one. For example, there may be 96.5%, 95.5%, and 94.5% versions: the screen looks the same, but the long-term return rate differs.

A reward that returns a set percentage of your wagers.

A feature that can trigger at random at any time in the base game.

A jackpot that can trigger randomly on any spin, with no specific combination needed.

A wild that is added at a random position during a spin.

A statistical test to check whether numbers are truly random.

A reminder at set intervals showing your play time and net results.

A game provider founded in Valencia, Spain, in 2011. It started with social casino games and began supplying real-money slots in 2016. It is known for slots with 3D graphics and storylines, and features like "Total Replay."

A slot provider launched in 2014, known for its "Daily Drop" jackpot that is guaranteed to hit every day. It was acquired by NetEnt in 2019 and has been part of the Evolution group since 2020.

One vertical column of symbols that spins. Five reels is the standard.

A slot studio from Wales, UK that began releasing games in 2020. An affiliated studio that uses Pragmatic Play as its sole distribution channel, it created the worldwide hit "Big Bass Bonanza" and the Big Bass series.

An xSplit variant where an entire reel splits in one go.

A reward given for getting someone else to sign up.

A game developer and aggregator that launched in Malta in 2010. It's known for the Money Train series and the Dream Drop jackpot, and it runs "Powered by Relax," which distributes other studios' games.

A bonus given to existing players when they deposit again.

A feature that spins once more while some reels or symbols stay locked in place.

When scatters land again during free spins and add more spins to the round.

The probability of losing your entire set bankroll. It varies greatly with bet size, a game's volatility, and play time, and when RTP is below 100%, it approaches 1 the longer you play.

A VIP chip that cannot be cashed out and can only be used for betting.

Romania's National Gambling Office. It has issued online gambling licenses since 2015, creating one of Eastern Europe's largest regulated markets, and is known for a strict structure that also requires separate licenses for game suppliers.

One horizontal line. A 5×3 slot has 3 rows.

The number of observations used in a measurement. In slots, the number of spins.

A symbol that triggers free spins and other features when a set number lands, regardless of position.

A win type where a set number of matching symbols pays regardless of position.

The base amount a jackpot resets to after it is won.

A program that lets you block yourself from playing for several months up to permanently.

One stretch of play in a single sitting.

A provider launched in 2012 and headquartered in Douglas, Isle of Man. With several development studios across Europe and Asia, it makes slots, arcade and table games, and player engagement tools, and has released many Megaways games.

A collection of terms such as win presentations like Big Win and Mega Win, play expressions like dry spell and tease, streaming terms like bonus hunt and slot streamer, and service terms like social casino and sweepstakes casino.

A collection of online casino promotion terms such as slot tournaments, leaderboards, Drops & Wins, prize drops, in-game missions, free rounds, rakeback, and level-up rewards.

A broadcaster who live-streams slot play.

A collection of the types of pictures (symbols) you see on a slot screen. It covers regular symbols, wild types, scatters, money and collect symbols, and special symbols like mystery and multiplier symbols, all in one place.

A collection of themes commonly used in slots and the features that often come with them, from classic fruit and 7s to Egypt, Greek myth, Norse myth, Aztec, Asian fortune, pirates, fishing, candy, horror, and branded slots.

An event where players compete for points over a set period, with prizes by rank.

A provider launched in Tbilisi, Georgia, in 2015, best known for the crash game "JetX." JetX came out in January 2019, about three weeks before Spribe's Aviator, and is considered one of the games that opened up the crash game genre.

A casino game app played only with virtual coins that cannot be exchanged for cash.

An Asia-focused slot provider launched in 2007. Headquartered in the Philippines, it is widely known in Southeast Asia for themes built on Asian culture and for fishing games, and it has recently been expanding into the European market.

This is Spain's online gambling regulator. The 2011 Gambling Act opened the market in 2012, and online slots were allowed in 2015. No new general license tenders have been held since 2018, so the only way into the market is by acquisition.

One turn of the reels. It means a single round.

A Malta-based slot provider founded in 2014. It is known for its Demi Gods series, the "Hold & Hit" bonus, the "Universe" concept that links multiple games, and its network tournament "Spinoleague".

A symbol holding two or more of the same picture in one position, counted as multiple symbols.

A structure where symbols split and the grid grows.

A system where a multiplier is marked on a winning cell and applies to the next wins there.

A wild that spreads to turn neighboring positions into wilds.

A provider launched in Tbilisi, Georgia in 2018 that created the crash game "Aviator." It specializes in short-round "turbo games" rather than slots, and uses the Provably Fair method in all of its games.

A wild that lands as a vertical stack covering several positions.

A slot provider founded in the Netherlands in 2015, now part of Greentube within the Novomatic Group. It is known for "Super Stake," which unlocks features when you raise your bet, "Quattro," which spins four slots at once, and branded Megaways slots.

A bonus where the bonus amount itself cannot be withdrawn, only the winnings.

A wild that stays locked in place for several spins after landing.

A higher-tier bonus that starts with better conditions than regular free spins.

A special scatter found in Pragmatic Play's Super Scatter series. While triggering free spins, it also pays an instant win from 100x up to 50,000x the bet, depending on how many land together.

This is Sweden's gambling regulator. It ended the state monopoly in January 2019 and opened a licensed market with strict rules, such as allowing only a first-time sign-up bonus. Regulated market revenue in 2025 was 28.2 billion kronor.

A slot site in the US that operates under sweepstakes (prize draw) law.

Switzerland's casino regulator. Under the Money Gaming Act confirmed by a 2018 referendum, only Swiss land-based casinos can run online casinos, and about 3,000 foreign sites are blocked.

A feature where multiple reels are matched to show the same symbols and spin together.

An effect that builds tension as if a bonus is about to trigger, then misses.

The belief that some slots are "paying well lately" or that a slot that hasn't paid in a while is "due." Slot results are independent on every spin, so past results can't predict the next one.

The expected loss a casino uses to calculate a player's value.

The difference between the designed figure and the figure actually observed.

An independent slot studio founded in Stockholm, Sweden in 2012 by former NetEnt developers. Putting "quality over quantity" first, it releases only about one game a month, and is known for Esqueleto Explosivo and the Pink Elephants series.

A jackpot split into several levels, such as Mini, Minor, Major, and Grand.

A state where your emotions are shaken and you make reckless bets unlike your usual play.

Setting how long you will play in one sitting.

The full amount you wager on one spin.

A bonus where you move along a board path collecting prizes.

A symbol that changes other symbols into higher-paying ones.

A theme about pirate ships, treasure chests, and maps.

A mechanic used in Pragmatic Play's Triple Pot lineup. Colored scatters are collected into three pots (jars) in blue, red, and green, and the pots filled in the bonus add multiplier effects.

A mechanic where winning symbols disappear and new symbols drop in, allowing chain wins.

A mechanic where winning symbols disappear and new ones drop in from above, so a single spin can produce a chain of wins. Also called cascade, avalanche, or reaction.

A setting that speeds up the reel animation.

The gambling regulator for Great Britain. Launched in 2007, it is considered to have some of the strictest rules in the world, such as online slot stake limits and spin speed limits.

A distribution in which every value is equally likely.

A separate gaming area reserved for high-stakes customers.

Statistical values that show how widely results are spread around the average. In slots, they are the math behind volatility: even at the same RTP, a larger standard deviation means much more uneven results.

A modern slot with 5 or more reels, animations and bonus features.

The idea that the reels you see on screen differ from the reels that set the real probabilities. How many of each symbol are placed on the reel strip determines each symbol's chance of appearing and the RTP.

The tendency of a slot to pay out wins, describing how often and how big they come. Also called variance, and it is a separate concept from RTP.

A single number that expresses a slot's volatility. Based on the standard deviation, it shows how widely results can scatter at a set confidence level, and the higher the number, the more uneven the results.

The amount you must bet before you can withdraw a bonus.

A wild that moves one position with each spin.

A win type where, instead of lines, matching symbols on consecutive reels from the left form a win.

A slot provider that launched in Cyprus in 2010 and later moved to Malta. It's known for its "Volatility Levels," where players pick the volatility themselves, as well as Hold the Jackpot and the Coin series.

Setting different appearance rates for each symbol or outcome.

A bonus given to players who sign up and make their first deposit.

A bonus where you spin a wheel to receive prizes or features.

A jackpot that pools bets from multiple casinos and multiple games.

A versatile symbol that substitutes for other regular symbols to complete a winning combination.

The amount you decide in advance that, once won, means you stop.

The high-value jackpot brand of Games Global (formerly Microgaming).

An ELK Studios feature that lets you choose from several bonus entry modes at different prices.

A slot provider founded in 2013 by Fredrik Elmqvist, a former NetEnt CEO. Known for visually rich slots like Vikings Go Berzerk and Valley Of The Gods, the Gigablox and Splitz mechanics, and its external studio program "YG Masters".

A gaming machine company founded in 2007 by Johnny Ortiz, headquartered in Luxembourg with development in Barcelona, Spain. It started with video bingo, entered video slots in 2016, and is especially strong in Latin American casinos.

A gentle approach: raise the bet by 1 unit after a loss and lower it by 1 unit after a win.

A testing and certification body that launched in 2003 in London, UK, as a self-regulatory organization for the online gambling industry. It tests game software and RNGs, awards the "Safe and Fair" seal to operators, and also handles player dispute resolution (ADR).

A Malta-based slot provider founded in 2010 that also runs the Game Aggregation Platform (GAP). It was acquired by IGT in 2022, and when Apollo bought IGT's gaming business in 2025, it became part of the new IGT group.

An online game testing and certification body headquartered in Melbourne, Australia. It tests the random number generators (RNG) and RTP of online casinos and game providers and issues certificates, and is often seen certifying crypto casinos and smaller providers.

Nolimit City's own in-house game features. This page gathers 20 mechanics that start with "x", such as xWays, xNudge, xSplit, and xBomb.

An option to pay a little extra on your bet to raise the chance of entering the bonus.

A wild explodes, removing nearby symbols and adding +1 to the multiplier of the next cascade.

If you reach the max win, you get one more chance to boost it by 2x, 3x, 5x, 7x, or 10x.

If a single cascade has 2 or more clusters, the multiplier gets +1 from the second one onward.

A crash-style feature where the multiplier climbs and could burst at any moment.

A feature that can hit the max win in a single go without any other feature.

The screen glitches mid-spin and drops special feature symbols.

Sucks in symbols on screen and spits them back out as split symbols.

A moving character picks up symbols of the same color and pays out.

A feature that unleashes several x mechanics at once within a single spin.

A wild dedicated to a specific reel is pushed to expand across the whole reel, adding +1 to the multiplier.

Wilds nudge one position at a time to cover the reel, adding +1 to the multiplier with each nudge.

Removes wins smaller than the bet and stores them toward feature progress.

Expands the game screen (active area) to increase win chances.

When xSplit lands, the symbols to its left in that row split in two and the space becomes a wild.

Buy extra spins at the end of a round while keeping your progress.

An xWays symbol expands into 2 to 4 of the same symbol, greatly increasing the number of ways.

Adds +1 to the multiplier of nearby regular symbols and wilds.

A game where you bet whether a number from 0 to 100 will land above or below a target.

A TV-show-style live game built around a host, a big wheel, and bonus games.

A format that streams games run by a real dealer in real time.

A game where the multiplier rises with each tile you open while avoiding mines.

A machine-style game where you build a poker hand from five cards to earn a payout.

A game where numbers on your card are drawn, and the first to complete a set pattern wins.

An instant lottery-style game where you scratch to reveal hidden symbols.

A game where you cash out before a rising multiplier randomly stops.

A game where you pick numbers from 1 to 80 and are paid by how many match the 20 drawn.

A game where a ball bounces off pins and lands in a slot at the bottom, paying that slot's multiplier.

An arcade game where you shoot swimming fish and earn multipliers for catching them.

A game where you guess whether the next card will be higher or lower than the current one.