Unpredictability is omnipresent in life, from dealing playing cards, through contracting an illness or getting promoted, to the rise or fall of equity markets. For those attempting to make the calls on how economies will fare it is important to distinguish between three different forms of unpredictability. Rolling dice conveniently illustrates all three.
With a well-balanced six-sided die, the probabilities of all possible outcomes can be calculated in advance. For example, getting three sixes in a row should happen on average once every 216 times. We call this intrinsic unpredictability, as it depends only on the random properties that are intrinsic to rolling the dice.
via In all probability, economic forecasts are probably wrong.