Chris Wilson talks about how PoE implements RNG (and procedural generation) little bit in his GDC talk which is on youtube, he mentions one of the design pillar

Chris Wilson talks about how PoE implements RNG (and procedural generation) little bit in his GDC talk which is on youtube, he mentions one of the design pillars of the game is "multiple overlapping axis of randomness" the whole video is really good. I love the amount of randomness that exists in the game some of the items that can drop are completely build defining (legion jewels and Watcher's Eyes for example) but also hugely random if you manage to get your hands on one with interesting rolls it feels like possibilities are endless. At the same time I think they have realized players like some amount of agency as well a lot of the newer content they've introduced has semi-deterministic outcomes where player's action can influence the rewards stuff like Syndicate hideouts, incursion temple etc. Gives you some control over what items you will get at the end of the content.