While the slot machines of today have been developed in
the image and style of the original machine prototype, they
function via an entirely different system. Nowadays, the
resulting symbol combinations are dictated by a computer
chip inside the slot itself, rather than by the activity
of the spinning reels.
Predetermined stopping points controlled by the computer
chip are used to stop each reel, which in turn, are regulated
by small, digitized bursts of electricity. Not like the
currents of electricity which operate standard electric
devices, the controlled bursts generated by the step motors
are able to halt the spinning reels at exactly the right
Although this sounds like pre-programming, which it is,
the pre-programming that involves the payout percentage
of a machine is determined by another device - the random
number generator (RNG). With the RNG in place, each spin
of the reels has an equal chance of striking a big win.
With the RNG engaged, hundreds of numbers ranging from
one to several billion are being generated each second.
The number that is generated the exact millisecond a player
presses the spin button or pulls the slot arm is the same
number that will then be processed into a program that syncs
the number with where the particular stopping point will
be for each reel.
This is how the operations of
a 3-reel slot machine take place.
You pull the handle or press the button, and the computer
records the next three numbers from the random number generator.
The first number is used to determine the position of the
first reel, the second number is used for the second reel
and the third number is used for the third reel. For this
example, let's say the first number is 123,456,789.
The player begins by pushing the spin button or pulling
the handle of the machine, at which time the computer chip
will record the very next three numbers that were generated
by the RNG. Each number corresponds to one of the reels
(3 numbers for 3 reels), which are then processed into a
simple calculation that will ultimately create a number
that tells the reels where to stop. Let us say the first
number corresponding to the first reel is 333.
The calculation that is used next involves dividing the
RNG generated number by multiplied values of 32, up to a
value of 512. Since each machine is programmed differently,
for the above example we shall say the computer chip uses
the value of 32.
After running this particular calculation, we get 14 with
a remainder of 2. The remainder is an important consideration
for it shows there are only 32 possible end results of this
calculation (it cannot be larger than 32 or smaller than
0). The computer then maps the 32 possible values out as
stops on a computerized reel of 32 stops.
These computerized stops each correspond to the actual
stops on the reel (they tell the reels which stop to cease
spinning). Since there are less actual stops on a reel than
the 32 stops on the computerized reel, some of the actual
stops will correspond to more than one of the computerized
stops. And when you add all three reels together, the possibilities
This mode of operation is a great advantage to modern day
slot machines. The computer system is responsible for governing
whether a machine is going to be loose or tight, and just
how much money it pays out over the long run. Not only is
less oversight required, the outcome will always be mathematically