The only way to influence rolls is when you are gambling. When you gamble your character level influences the ilvl. I can never remember if it’s +5/-4 or the other way around, but basically if you have a character below certain ilvl thresholds, then you can take certain affix and suffix out of the pool of options for what can roll. What can roll will still roll at random though.

Three resources that can be helpful:

https://diablo2.diablowiki.net/Item_Generation_Tutorial
https://asukawang.com/blog/under-the-hood-diablo-ii-item-generation/
https://www.cis.upenn.edu/~cis110/11fa/hw/hw06/index.html

Last one cracked me up

Try gambling a bunch of rings on a high level char

Most will be low level shit

Even tho ilvl = +/-5 clvl

The ilvl of items depends on the mlvl of the monster. That's based on the level of the area.. (85 being the highest outside of terror zones)

Champions get +2 on top of area level

Bosses and superuniques also have differing mlvl (baal =99)
Item level = monster level for drops