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Slots Guide

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The Full Slots Guide

Every day, millions of players wager billions of dollars on slot machines.

Slots are the hottest casino games going, both online and offline. In the United States, slots account for about 80 percent of casino revenue, and electronic gaming has grown by leaps and bounds in Europe and on the Pacific Rim, too.

That’s heady stuff for slots, with their humble beginnings in a three-reel game called the Liberty Bell, invented by San Francisco mechanic Charles Fey in 1895.

To claim their place at the top of the casino class, slots went through a technology revolution that made them multi-faceted entertainment experiences with animation, sound effects and games within a game as bonus events.

Jackpots are important, too. The chance to win thousands of dollars or more for a very small bet is in every player’s mind. Understand that the really big pays are rare treats and losing sessions are common. Enjoy the wins when they come, and meanwhile, have fun with slot entertainment.

Every game has its basics. Here are some things every player should know modern video slots, online and offline.


Let’s cut to the chase and put every player’s top questions first: How can I win? How can I tell when a game is ready to pay off?

The short answer is that slots are games of pure chance that give no sign when they’re ready to pay off.

Las Vegas-style slots, used in most American jurisdictions including online as well as a growing number of casinos around the world, use a random number generator to determine results.

When you spin the reels, the RNG generates numbers. Other programming then maps those numbers onto reel positions. If, for one reel, the RNG generates No. 18, and the map says No. 18 corresponds to a cherry symbol in the middle position, then the game will stop the reel with a cherry in the middle position.

There is no way to anticipate what the RNG will do. You just bet your money and take your chances.

Now, let’s get down to basics.


The most popular slot games are played on a video screen. The games you play on your computer, phone or pad use the screen of your device, while those in offline casinos have the screen in a free-standing machine.

Online, if your device has touch screen capabilities, you can touch to wager and play. If not, you can point and click with your mouse. Offline, you can either touch the screen or use buttons on a panel below the screen.


On the screen, you’ll find reels that spin when you play, and each reel contains a number of symbols.

The symbols can be almost everything. Symbols that have been used for decades, such as 7s, fruit pictures and bars, are still in use, Many games have symbols designed to reflect the game theme – gift boxes, noisemakers and balloons in the popular game Jackpot Party, or scarabs, sphinxes and pyramids in Cleopatra.

The most common configuration has five video reels, each three symbols deep – effectively a 5-by-3 grid. However, some games use reels that are four symbols deep, some use more or fewer than five reels, and some have different numbers of symbols on different reels.

Slots Guide: MAKING A BET

To play, you’ll need credits on a meter on your screen. Offline, you slide paper currency into a bill validator to buy credits. Most modern slot machines no longer have slots to drop coins.

Offline, most credits are bought via electronic funds transfers. Check the rules on the website where you plan to play for rules on how to buy credits.

You bet by touching buttons on the screen or, on offline games, by hitting buttons on a panel just below the screen. Choose your bet size and hit the button to spin the reels.

Slots Guide: PAYLINES

As has been the case on slots ever since the Liberty Bell, the idea is to line up matching symbols on a payline that extends across the screen.

On early three-reel slots, there was only one payline, straight across the middle symbols on each reel.

Today, video and online slots almost always have multiple paylines, and they don’t have to be a straight line. The first massively popular video slot, Reel ’Em In in 1997, had five paylines. There were lines straight across the top, middle and bottom reel positions, and there was a V line and an inverted V, or chevron.

Slots have evolved, and almost any path connecting symbols across the screen can be a payline. Thirty, 40 and 50-line games are common, and 100 line games are out there.

Slots Guide: PAY TABLES

Different winners pay different amounts, with those that occur most frequently paying the least and the rarest paying the most.

You usually can get a look at the pay table by touching the Help menu.

To give a simple example, imagine a game with just four different symbols: 7s, cherries, oranges and watermelons.

Each pays off when you line up three, four or five in a row.

When you look at the pay table, you’ll see a picture of the symbol along with the payoffs for each winner. Four our sample, if you see a 7 icon followed by the number 5,000 next to five 7 icons, the number 500 next to four 7 icons and 50 next to three 7 icons, it means the game pays 5,000 credits if you line up five 7s, 500 for four 7s and 50 for three 7s.

Next to a cherry icon, you might see payoffs of 250 for five cherries, 100 for four and 25 for three, then 150, 30 and 10 for the oranges and 50, 15 and 5 for the melons.

If you get one of the smaller payoffs on only one line, you might win less money than you wager. That’s part of the normal workings of modern slots. The small paybacks are designed to keep you engaged and give you credits to keep playing until bigger winning combinations and multiple-line paybacks come.


A huge part of the fun on the slots and a large portion of the payback comes from bonus events. Sometimes these are launched by landing special bonus symbols on the screen. Some machines have what are called “mystery bonuses” that can launch even on an apparently losing spin as a random number generator tracks playing time, total wagers or other parameters determined by the casino and the game manufacturer.

Bonus events can take many forms, but these are the most common:

**FREE SPINS: These are the most common bonuses, especially on low-denomination slots such as penny. You get a specific number of free spins. Sometimes they’re on the regular game reels, but sometimes there are special free spin reels that include only high-paying symbols, and sometimes there are extras such as symbols that multiply your winnings on a given spin.

**PICK-A-PRIZE: Instead of the reels, your screen shows you a scene related to the game theme. On that screen, you touch items to reveal bonus credits. A durable example is the long-popular Jackpot Party, in which you touch gift boxes to reveal either credits or a “Pooper” character who ends the party.

**WHEEL SPINS: A vertical wheel is marked off into segments, and you touch a button or a screen to start it spinning. The position that stops on top indicates your credit win. The prime examples are classic Wheel of Fortune slots.

When you’re in a bonus event, you are adding credits to your meter without risking money on additional wagers. They’re fun to play, and to many players, the bonuses are why they play the games.


If you see a game with a display showing constantly increasing jackpot amounts, you’re playing a progressive machine.

On progressives, a portion of each bet is added to the pot until somebody wins it. After it’s won, the jackpot amount is reset at a base value and starts building again.

Some jackpot slots run into the millions of dollars and can go months, even years without someone winning. But video and online slots often have frequent-hit, multi-tiered jackpots with levels such as mini, minor, maxi and grand, or bronze, silver, gold, platinum.

The lower-level jackpots may be only a few dollars, designed to give you the excitement of winning and a small sum to keep playing. Top levels can be hundreds or thousands or more.

Some progressives are won by lining up special jackpot symbols, but mystery jackpots are very common. One frequently used way to program mystery jackpots if for the RNG to set a target jackpot, and the player whose bet increases the pot to that amount wins the prize.


For many decades after the Liberty Bell, most slots had three mechanical reels. You can still find such games offline today.

Online, representations of three-reel games work in the same way as the video slots described above. Offline, there are programming differences because of the need for physical reels to be small enough to fit in machine casings, but your results still are determined by a random number generator.


Slot results are random and unpredictable, and odds are set up so the house will win more often than you do. Enjoy the entertainment experience, don’t bet money you can’t afford to lose, enjoy the wins when they come, but play primarily for fun. Good luck!