To be concrete, consider the simple case of throwing a dice. Every face has a probability to be thrown. The outcome of all throws is non-random (it is a fixed pattern determined by throwing the dice a lot of times).
On this pattern, you can apply a new chance of appearing. If you throw with two dices, a new pattern will emerge. This is because different dices will produce different outcomes (only in the case of perfect dices, the chance distribution of each one is the same as for the others). The chance that the dices used in separate throws is the same is very small. But there is a chance. And this chance is measured by applying the chance to the non-random chance distributions of a dice.

To be concrete, consider the simple case of throwing a dice. Every face has a probability to be thrown. The outcome of all throws is non-random (it is a fixed pattern determined by throwing the dice a lot of times).
On this pattern, you can apply a new chance of appearing. If you throw with two dices, a new pattern will emerge. This is because different dices will produce different outcomes (only in the case of perfect dices, the chance distribution of each one is the same as for the others). The chance that the dices used in separate throws is the same is very small. But there is a chance. And this chance is measured by applying the chance to the non-random chance distributions of a dice (for every dice this is a different distribution, though they are all quite alike).