It is possible to use the stealth skill to "hide" in D&D 5e. But are there any mechanical benefits to doing so?
In combat, you gain advantage on an attack if your target can't see you, and confer disadvantage on their attack. Since you must be unseen to hide in the first place, what extra benefit does hiding get you?
Out of combat benefits might be harder to enumerate, but are there good examples where hiding might provide something more than just a good stealth check would?
Best Answer
Best to go back to the source on this; italics are my emphasis.
PHB p.177
PHB p.177
PHB Errata
PHB p.179
PHB p.183
Note: Darkvision in darkness is dim light and results in a lightly obscured area. Darkvision added to dim light gives bright light. Torches, lanterns etc give bright and dim light.
My takeaways from all of this:
Hidden means "unseen and unheard" (p. 195) so it incorporates and is superior to being merely "unseen". If the circumstances are right it can be better than invisibility without needing the spell.
Consider a combat with darkvision only (everywhere is lightly obscured). If there are things to hide behind (pillars, tables, walls) then the rogue can move behind one, hide and move anywhere that is no closer to the enemy with a good chance (Wisdom (Perception) at disadvantage) that no one knows where he is. Anyone targeting has to guess his location and even if they do they attack with disadvantage. If you are clever, you can move where the enemy is likely to move past you (AoO) on their turn or have your big strong Barbarian/Fighter/Ranger/Cleric companion grapple someone and bring them to you.
Example
A party is camped at night in a featureless plain (i.e. no cover at all) and are attacked by a group of goblins. Now, goblins have this:
and
Assume that there is a campfire giving bright light for 15 feet and dim light for another 15 feet. Also, assume 2 (of 4) PCs have darkvision.
At the start of the combat, the goblins spread out around the camp and attempt to hide. They have time to get in position so let's give them advantage. As they approach they are "unseen and unheard" and have a Dexterity (Stealth) DC of [highest 1 of 2d20]+6.
A passive Wisdom (Perception) check is appropriate (with disadvantage unless the goblins are within dim light range and the PC has darkvision) to see if the PC on watch hears or sees anything as they approach to just inside the ring of (dim) light. A non-proficient PC with average wisdom has a passive Wisdom (Perception) of 10, -5 for disadvantage means he is not going to hear anything, ever. A 1-4 level Cleric will have a passive Wisdom (Perception) of 15 or 16, by 8-12 level this rises to 19 to 20 and at 17-20 to 22 say; the goblins will creep up un this gal about 80%, 55% and 36% of the time respectively.
If they are undetected, they attack with surprise, each shoots an arrow (with advantage if within the bright light) steps out of the light and darkvision range (5 feet). Attacking reveals their location, so they use the remainder of their movement (25 feet) to circle around in the dark to confuse the party.
Now the PCs are in a real bind - they have no targets (every goblin is in the dark) but the goblins can see them due to the fire. If they extinguish the fire the non-darkvision PCs are blind but the darvision PCs aren't much better off.
Every turn each goblin moves towards where the PCs last were, fires his bow (revealing their location) if he sees one, then moves out of darkvision range and hides again (without advantage). Now the PCs can move towards a given goblin, actively looking so we make active perception checks (with disadvantage for low light). What are the chances they find him? For Wisdom (Perception) modifiers of 0, +5 and +10 they are 12.7%, 30.9% and 55.5% respectively.
If they do find him, well the goblin was at least 65 feet away so without special abilities no one can close to melee this round; they can use a ranged weapon or spell or a saving throw type spell (normally overkill for 1 goblin but needs must).
If the goblin survives he can move, Hide (bonus action) and Dash (action) to start the cat and mouse game again. Meanwhile the other goblins are sniping all the while.
Be careful; this is a likely TPK for low to mid level PCs and even high level PCs will burn some serious resources.
Real world hiding
Just to remind you that people can be hidden without being invisible, can you see the sniper in this photo? Better be quick because they'll use their action this round to put a bullet in your head. You have 6 seconds if you use your action to Search.
If you didn't find them then you can practice with this Wired article.