Slot Machine Basics 101

Let's begin with a little bit of basic knowledge about slot machines.
Modern Slot Machines work on a computer program that randomly selects winning combinations. Winning percentages and odds are set by the manufacturer and are calculated by millions of spins made with computer simulations.
A Slot Machine is a mechanical device employing three, four, five, or more circular reels of varying dimensions. Each of these reels has several symbols, either painted on or attached to it. Most common designs are Cherries, Bars, the Jackpot Symbol, and the Number 7.
Theme Machines are very popular, using red, white, and blue 7's symbol which trade on American patriotism. To better understand Slot Machine Strategies and how Winning at Slot Machines can be easy, you must first know what kind of Slot Machine you are playing and understand Slot Machine Strategy.
Three Reels vs. Four Reels
Common sense should dictate that it is far easier to line up three matching symbols for a Slot Machine win, than four. To get four of anything is very hard, even on liberal Video Poker. On a Reel Slot Machine, three 7's can be achieved much more often than four 7's on a Four-Reel machine. Look for Three Reel machines to play.
Progressive Slots
Progressive Slot Machines are usually Four-Reel machines which offer an open-ended jackpot that increases in value after each pull on every machine within a linked group. The top jackpot can be won only if the maximum number of coins is played and all the winning symbols correctly line up on the pay line. Progressive Slots do not pay off very often, however if you want to play a Progressive Slots, pick one whose Primary and Secondary jackpots are at a high level.
Two-Coin vs. Three-Coin Machines
In a Two-Coin machine, for the top jackpot, or maybe even the top two or three jackpots, the second-coin play will pay considerably more than just double the one-coin jackpot. For example: top jackpot payoff on a Two-Coin machine is three 7's, paying $1,000, the same three 7's pays only $400 if you played only one coin. The Three Coin machine will show much higher payoffs for the top jackpots with the three coins played. Three-Coin machines might look more lucrative in their payoff than Two-Coin machines, but don't be fooled! The player also has to bet more to get the higher payout. Consequently, the player will lose more money. One final piece of advice: whatever slot you play, Two-Coin, Three-Coin, Four-Coin, etc., always play the maximum number of coins. If you don't, you are not maximizing your winnings.
One Payline vs. Three Paylines
Most Slot Machines show the Center line marked as a payline. To win you must line up a winning combination on that center payline and on that line only. But many machines show Three Paylines: at the top, center, and bottom of the window. This means that a winning combination lined up correctly on any of the three Paylines will pay. The advantage of Three-Paying Machines is they give you more chances of winning and you can get double and triple pays if winning combinations appear on more than one payline together. The disadvantages are that the payoffs are usually very small and the top jackpot is paid only if you line up the proper winning symbols in the correct sequence on the bottom, or third payline. Another disadvantage is that Three-Payline machines are always three-coin machines. Some machines offer five, or even eight paylines but, once again, you have to play five or eight coins per pull. Remember, great advice, play Two-Coin maximum, Three Reel, One Payline Slot Machines.
Double-Up Symbols
An increasing variety of machines now employ so-called Double-Up symbols on their reels. This symbol, usually circular or in the shape of a diamond in a circle, and always bearing the words "Double" across its face, can be very valuable to the slot player. The payoff amount is Double and these Double Symbols also substitute forany other symbol. However, there are not many Double Machines available at casinos. The good Double-Up machines are normally found stuck somewhere in the middle of a group of bad machines, or are relegated to some obscure part of the casino.