D&D (2024) Heavily Obscured/Greater Invisibility and targeting spells?

[Zardnaar]

So I may have messed up and encounter

Rules say you can't target someone vehind full cover.

Firing into heavily obscured area eg darkness you are blind. If someone's in darkness on a grid would you put minis down and let PCs fire at them with disadvantage or does being "blind" prevent that?

Greater invisible also says something like you cant target them. But you can use disadvantage to attack. I ruled this as you cant aim say Eldritch Blast or archer but can swing a sword blindly if they're in your grill.

Once again say mini on battlemap. Players will know where that mini is even if it's invisible. Wat happens if you're invisible in the darkness.

Hunger of Hadar similar deal. They're blind but you gave disadvantage to hit them. With devils sight you woukd gain advantage to hit?

How are others running this. I may have screwed up an encounter badly but idk.

 

[AlViking]

You can target unless the spell specifically states target you can see. Eldritch Blast is just a ranged spell attack so attack with disadvantage. Hunger of Hadar is an area effect centered on a point within range so it's unaffected. You can't magic missile the darkness but you can fireball it. Assuming the point is not completely obstructed of course.

 

[mellored]

Many spells say "target you can see". But not all.
Eldritch Blast doesn't.

Also, if both parties are blind, then you get both disadvantage and advantage, which cancels out (also means no sneak attack).