There are basically two categories of cash-paying slot machines. First we'll look at free slot machine games without all of the bells and whistles. These types of slots and fairly straight forward and not much explanation is required. Then we are going to talk about progressive slot machines and video slots. These are the more recent (and popular) slot games to come around in recent years. Players have fallen in love with video slot machines because they tend to offer multiple pay lines and the opportunity to win extra money via bonus rounds.

• Straight slot machines - These types of machines always pay earnings according to a predetermined payout schedule that pays the same amount every time a specific symbol combination is hit.

For instance, a straight slot machine will have a payout schedule for the amount of coins one bets. The jackpot for a one coin bet may payout 800 coins, while a two coin bet pays 1,600 coins and a three coin bet pays a jackpot of 2,400 coins. Depending on what the value of the coin size is, the monetary payout will vary.  For this particular payout scale, if the coin size was fifty cents, a three coin bet would payout $1,200 (.50 x 2,400), while a coin size of $1 would payout $2,400 (1 x 2,400) for a three coin bet.  On a straight slot machine, these payouts will always be the same.

• Progressive slot machine - The jackpot payouts for these types of machines are progressive, meaning they progressively grow as more coins are put into the machine.  Depending on the type of progressive jackpots (stand-alone, in-house and wide area) the more bets are made, the greater the jackpot grows.  Stand-along progressive jackpots build from a single machine, in-house progressives grow from a network or bank of machines located in a single casino, and wide area progressive slot machines grow the largest because they are tied into a network of slots being played at multiple casinos at once.

All progressive slot machines will display the accumulating progressive jackpot on a digital monitor typically located at the top of the machine.  When the jackpot is hit by a player, the amount will automatically drop to whatever the default jackpot is, and will begin accumulating again.

Players can determine whether a machine is progressive or not by looking at the top payout on the payout schedule.  If it is, then the top payout will say "progressive".  Other than that, the payout schedule will look like any straight slot machine, for other than the top payout, all other symbol combo payouts are fixed on progressive machines.

Some things to keep in mind about progressive slots:

Players generally have slightly better odds of winning on these machines, which amounts to about 2%.  Although this is better than nothing, luck is still the overall factor for winning it big.

In order to take home the largest progressive jackpot, players must bet on all of the pay-lines of the machine.  For instance, a progressive machine with a fixed bet of $.50 and ten pay-lines would have a max bet of $5 for each spin (.50 x 10).  Players must be sure they can afford to bet this much over an extended length of time, if they have hopes of winning the progressive jackpot.  If not, one should find a machine with a lower max bet.  Just keep in mind that each pay-line offers a chance to win.  In other words, betting on multiple pay-lines simply gets in more bets on a single spin of the reels.

Playing the max bet on a progressive machine may end up costing more; However, keep in mind that the difference in jackpot winnings is prodigious between a max bet made on all the pay-lines at once than a bet made on one or a few pay-lines. This is why you will hear most players advise to always bet the max on progressive slots.  If not, and you happen to hit the jackpot symbol combo, you will lose out on a whole lot of winnings.