Do you need to be hidden to get advantage when attacking while unseen?

Question

I always assumed you needed to be hidden to get advantage when attacking/disadvantage when being attacked, but after looking at the rules I'm fairly certain this is not the case. There's a chance I'm reading into it incorrectly, though.

For example, assume I have greater invisibility cast on myself. No matter how many attacks I make, or whether or not my enemy knows where I am (but can't actually see me), do I still have advantage to hit and they have disadvantage to hit me?

I think that's what's accurate. This would implicate that "Hidden" means "Enemies don't know where you are and think you could be anywhere", which changes my prior understanding of hiding drastically.

Am I correct on this?

Answer 1

You do not need to hide

As you've stated, the rules for advantage are regarding Unseen Attackers and Targets.

Hiding successfully* simply means that they are uncertain or unaware of your location because you have, hopefully, successfully hidden yourself (unless they have another sense that discloses your location).

As soon as you attack, your location is known but the rules on Unseen Attackers and Targets remains in place (as long as you are still unseen.)

When a creature can't see you, you have advantage on attack rolls against it. If you are hidden--both unseen and unheard--when you make an attack, you give away your location when the attack hits or misses.

*Hiding successfully includes things such as a stealth roll beating perception and DM approval of your hiding spot as a valid location to hide.

Answer 2

You are reading this correctly.

Being hidden specifically means unseen and unheard. If you're merely unseen but still heard, you are not hidden, but still have all the benefits of being unseen, including advantage when attacking and others attacking you with disadvantage.