Because true randomness is not repeatable, many effects simulate randomness by using a calculation that generates seemingly random results for each value of a Random Seed property. Multiple instances of the same effect will give the same results if all of their settings—including the Random Seed property values—are the same. This allows you to get predictable, deterministic results, while still achieving the appearance of randomness.

Changing the Random Seed value doesn’t make things more or less random; it only makes them seem random in a different way.

You can add randomness to any property with the expressions in the Random Numbers category.