I was thinking about fallout 4 difficulty, and I think you should add a custom difficulty. Where for example, you want easy difficulty, but you want higher legendary spawning. Things like that, have under the custom difficulty screen a whole selection of all the different things you can tweak. As mentioned before the list could include higher legendary spawns, more enemy damage, lowered damage dealt and even if you want reduced healing rate on the lower difficulties. And by each you have a check box, and you can check the ones you want added then also next to them have a slider for you to indicate how high you want that selection effected.



Lets say I want to play on easy difficulty, but I want the same legendary spawn rate as very hard. So I would select easy, check off the legendary spawn adjuster, and then move the slider over from 0.5x (the rate legendaries spawn in on easy) over to 2x (the rate legendaries spawn in for very hard difficulty)


This is only my suggestion but I thought it would make things interesting to be able to mix difficulty styles into a way every player would like it to be.

That is a perfect idea for a sort of sandbox type of game. I think some mods might add something like that, I remember skyrim had some but I never really bothered installing difficulty mods for beth games, I only wanted enemies to do more dmg but I don't like to do little dmg myself.