From roulette wheels to action-adventure games, randomness plays a major role in the gaming world. It is for any scenario where opponents or scenes are created dynamically and for those where users need “on the fly” randomness.
This is a far cry from my memories of the 1980s, when gaming was a lot less enjoyable precisely because everything was predictable- if your character went on a mission once, the next time you played the mission would be exactly the same. As you can imagine, this got very boring very quickly.