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Different types of Slot Machines

By Henry Tamburin

If you love to play the slots then you had better know the difference between a Multiplier vs a Buy a Pay vs a nudge slot machine. Here’s a guide to help.



The term refers to slot machines that take multiple coins and the number of coins played multiplies the winning payoffs. For example one cherry on the pay line might pay 2 coins with one coin played, and ten coins with five coins played.


On most multiplier machines the payoffs are proportional to the number of coins played except for the jackpot. You usually get a bonus payoff for maximum coins played when you hit the jackpot. For example hitting three 7’s on the payline might pay 100 coins for one coin played but if you play 2 coins you would win 500 coins (instead of 200 coins). The overall return percentage for these machines includes the bonus jackpot payoff; therefore if a player plays less than maximum coins the theoretical return percentage is lower. This feature encourages players to bet the maximum amount on each spin.


There are some machines, however, that pay off in direct proportion to the number of coins played (e.g. in the above example the machine would pay 200 coins for 2 coins played). With these types of slots, you are not penalized with a lower return percentage for playing less than the maximum number of coins.


Buy a Pay

These types of machines are the most confusing to players. Their characteristic feature is that each coin played activates a set of jackpot symbols. In essence when you insert more coins you are “buying” additional jackpot symbols. An example is a Sizzling 7’s machine. If you inserted one coin and three Sizzling 7’s showed on the center payline, you would not win a thing. It’s only after you insert the second coin in these machines that the Sizzling 7’s jackpot becomes active (with one coin played the single bars, double bars, triple bars, etc are active but not the Sizzling 7’s).


It’s very important if you play these types of machines that you play the maximum coins. You would not feel very good if you hit a winning combination or worse a jackpot, and then discover that because you didn’t play enough coins, you end up winning nothing.


How do you recognize a buy-a-pay machine? Check the payout schedule on the face of the machine. If you see a different combination of winning symbols when a second coin is played compared to one coin played, this is a buy-a-pay machine.

On these types of slot machines, once the reels stop spinning symbols will move to the center payline from just above or below it. The most common nudge machine is a version of Double Diamonds. Some of the bars and diamonds will drop to the payline.


On these machines you could end up with a winning spin even if no winning symbols appear on the center pay line when the reels first stopped. This is the draw that gets players to play.


Wild Pay
This refers to a specific type of slot machine where you have the chance to double, triple, even five and ten times the winning payout if a wild symbol lines up on the pay line. If more than one wild symbol lines up, the payout is multiplied again.


Examples of these types of slots are Double Diamonds, Five and Ten Times Pay, and Treasure Tunnel. Slot players enjoy playing these machines because they like to see their winning payoffs multiplied.


Second Chance
On newer type slot machines, players have a second chance to win thanks to the new slot machines that offer “slot bonusing”.  An example is the bonus wheel on Wheel of Gold slot machine. When the bonus symbol appears on the pay line, the bonus wheel on top of the slot machine spins. When it stops it awards a player a bonus payout. The bonusing concept encourages players to play longer because psychologically they win something they didn’t expect.


A progressive slot machine takes a percentage of all the coins that are played and adds it to a jackpot that increases in value. When a player hits the winning jackpot symbols, he/she wins the total accumulated in the jackpot. The progressive meter then resets the jackpot to a minimum payoff. In general casinos have a leeway on what percentage of coins played is added to the jackpot (usually it’s between 0.5 to 2%).


There are two types of progressives. The Megabucks and Quartermania are examples of progressive slots that are linked to other similar machines in different casinos. By linking the machines, the jackpots often exceed several million dollars. These progressives are known in the industry as revenue participation games because the slot manufacturer owns the machine and the casino essentially leases the floor space to them. The revenue from these machines is shared between the manufacturer and the casino.


The other types of progressives are the multiple progressives like the Cool Million slots. On these machines you can win any one of three progressive jackpots by lining up specific symbols corresponding to the three jackpots. Another plus for Cool Millions is that they guarantee to pay the first million of a jackpot and the rest in installments (most other progressives pay the jackpot in installments over 20 years).