At 18th level, you gain preternatural senses that help you fight creatures you can’t see. When you attack a creature you can’t see, your inability to see it doesn’t impose disadvantage on your attack rolls against it.
You are also aware of the location of any invisible creature within 30 feet of you, provided that the creature isn’t hidden from you and you aren’t blinded or deafened.
The Devs made some comments over the years that hidden was the by-the-book way to conceal your location though DM may decide other methods also did.
Only thing is DM who decide to have invisible creature's location unknown must determine a check DC to possibly discover or else theyère impossible to.
@wax_eagle can you target a creature who is obscured but not hidden? More precisely, is hidden the only way to conceal position? @JeremyECrawford Being hidden is the by-the-book way to conceal your position. The DM may decide that other methods can also conceal it.
@fritomuncher My PC uses the invisibility spell, does he auto hide or do I still need to take the hide action to not be targeted? @JeremyECrawford The invisibility spell doesn't automatically hide you; you still make noise.
@quadhund But is the invisible person considered hidden as a result of casting invisibility?
@JeremyECrawford Invisible = unseen. Hidden = unseen and unheard.
DRAGONTALK PODCAST: Jeremy Crawford: When you're in invisible it doesn't mean your silent. If you really want to make sure people don't know where you are, you need to hide, you make a Dexterity (Stealth) check and you're hoping that they are not only not gonna notice any visual traces of where you are but they are not gonna hear you
There are a couple of good threads related to this topic that I'd like to recommend, but they were created and discussed under the 2014 rules. Useful for people using that edition, but I think they have still valid ruling for the 2024 rules (this is my personal opinion though, and I'm really not trying to convince many people about it)
I've seen a bit of back and forth on this, and I found an answer in a very odd location: The 2014 Rogue class features!
At 14th level, 2014 rogues get Blindsense
From this, you can extrapolate that you normally can't know which square in invisible creature is in.
So is Ranger's Feral Senses feature;
The Devs made some comments over the years that hidden was the by-the-book way to conceal your location though DM may decide other methods also did.
Only thing is DM who decide to have invisible creature's location unknown must determine a check DC to possibly discover or else theyère impossible to.
Considering those are 2014 features, it's of limited value for parsing how this is supposed to function for 2024.
There are a couple of good threads related to this topic that I'd like to recommend, but they were created and discussed under the 2014 rules. Useful for people using that edition, but I think they have still valid ruling for the 2024 rules (this is my personal opinion though, and I'm really not trying to convince many people about it)
This about 5E14 since in 5E24 the Rogue's Blindsense no longer exist and the Ranger Feral Senses was reworded.
Rules for Unseen Attackers and Targets though essentially remained the same regarding location.