How can a party defend against the Nightmare Haunting action of a Night Hag?

Question

This question was asked previously with respect to D&D 3.5:

What are the ways that a CR-appropriate party can stop a Night Hag's dream haunting?

There are some interesting answers there, but none of them were selected as the answer, and the monster has changed between editions. In particular, that question notes that Night Hag's CR was 9 in the previous edition, whereas currently they are CR 5. Presumably, a full-strength 5th level party of four adventurers should be able to defeat a Night Hag.

The Night Hag has the following action:

Nightmare Haunting (1/Day): While on the Ethereal Plane, the hag magically touches a sleeping humanoid on the Material Plane. A Protection from Evil and Good spell cast on the target prevents this contact, as does a Magic Circle. As long as the contact persists, the target has dreadful visions. If these visions last for at least 1 hour, the target gains no benefit from its rest, and its hit point maximum is reduced by 5 (1d10). If this effect reduces the target’s hit point maximum to 0, the target dies, and if the target was evil, its soul is trapped in the hag’s soul bag. The reduction to the target’s hit point maximum lasts until removed by the Greater Restoration spell or similar magic.

Let's assume that a 5th level party has already had a member suffer one night of Nightmare Haunting, and through player knowledge, role-played interactions, or Arcana checks, they've figured out they're facing a Night Hag and are expecting night two. Let's also assume they have all the knowledge of the Night Hag MM entry, knowledge of all the spells in the PH (and a mix of caster's who can prepare any spell up to 3rd level), and no magic items.

Contact can be "prevented" by:

• Protection from Evil and Good, which is 1st level, but only lasts 10 minutes.
• Magic Circle, which is 3rd level, and lasts an hour.

But since the Night Hag can come any time during the night, it's not clear that these spells are helpful. Magic Circle lasts longer if cast at higher level, but it doesn't help our 5th level party, and depending on your DM's sleep rules (not well-covered in RAW), may not be helpful until you get to an 8th or 9th level slot.

So in order to "prevent" contact, you wait for the Night Hag to arrive, then you cast the spell. But how does the party even know the Night Hag is there? See Invisibility can be used to see ethereal creatures, but it only lasts an hour, and the Night Hag can come any time during the night.

Then, if the party realizes the Night Hag is there but the Nightmare Haunting hasn't started, a spellcaster casts Protection from Evil and Good or Magic Circle. So the Night Hag goes away, and comes back after the spell expires. Repeat until no more spell slots, or at least deprive most of the party of their long rest.

So the party realizes it's fruitless to drive the Night Hag off before the Nightmare Haunting has begun. The spellcaster waits for the Night Hag to begin Nightmare Haunting a sleeping party member, then casts Protection from Evil and Good or Magic Circle. The Night Hag's 1/day power is spent. But do these spells even work? It's not clear to me that "prevented" means "stops" in this context. (And what does Magic Circle even do if you cast it on an area that already contains an excluded creature?)

In fact, the Night Hag still seems pretty challenging for higher level parties when used this way. Greater Restoration at least removes reduction of HP maximum, but killing the long rest can allow the Night Hag to systematically weaken a party. Etherealness lasts 8 hours and will eventually allow the party to post a sentinel in the Ethereal Plane (and hope the Night Hag doesn't kill the sentinel).

Please help before I TPK my players.

Answer 1

Magic Circle and Protection from Good and Evil

If the Hag always finds the party about the same time of night, they could cast either in preparation for the hag to keep the Hag out. Protection would be better, as the Hag might forget to detect magic and waste the casting on an attempt to touch someone who is already protected.

Protection from Evil and Good is only an action to cast, so it can be cast easily even when the attack has started.

[W]hat does Magic Circle even do if you cast it on an area that already contains an excluded creature?

Traps the creature inside. The spell says:

When you cast this spell, you can elect to cause its magic to operate in the reverse direction, preventing a creature of the specified type from leaving the cylinder and protecting targets outside it.

So could trap the Hag -- but the problem here is that the casting Magic Circle takes 1 minute. Unless the DM allows you to hold completion of a spell similar to a ready action -- But that isn't RAW.

Oil of Etherealness

Applying the oil takes 10 minutes, and it lasts 1 hour. It will allow you to be on the ethereal plane. If you fight and break the touch the Hag, the Haunt attack is used for the day. If you secure the Heartstone, she can't get back to the ethereal plane, and if you kill the Hag, she'll be banished back to Hell.

Turn the Hag

• Paladins of the Oath of Devotion's Turn the Unholy works when the Hags enters the material plane to attack.

• Paladins of the Oath of Ancient's Turn the Faithless doesn't require Sight, if the Fey or Fiend hears the chanting they have to flee.

• Paladins for the Oath of Vengeance can frighten a fey or fiend they see using Abjure Enemy.

Force Damage Won't Work, but Things of Force Do

A traveler on the Ethereal Plane is invisible and utterly silent to someone on the overlapped plane, and solid objects on the overlapped plane don't hamper the movement of a creature in the Border Ethereal The exceptions are certain magical effects (including anything made of magical force) and living beings.

However closer reading is that things made out of magical force hamper movement -- force damage doesn't pass through realms. This is made clear by a tweet from Jeremy Crawford:

https://twitter.com/JeremyECrawford/status/745062527118123009

No general rule causes force damage to pass from one plane of existence to another. #DnD

So while Magic Missle or Eldritch Blast won't help, the following will: - Leomond's Tiny Hut - Wall of Force - Force Cage

Wake the Sleeper Will Not Work

Originally I thought that waking the sleeper would work. I said:

Simple answer are typically missed.

Always keep one party member on watch. If someone always keeps watch (changing shifts so everyone gets full rest) they can look for party members having nightmares. Having a nightmare of terrifying images isn't a quiet thing -- ask any parent. Try putting the people with highest perception on watch at the times you're most vulnerable, like the middle of the night.

Once awake, the nightmare ends. If caught before an hour, the negative effects don't take hold. The ability only works on sleeping people on the material plane. The hags "Nightmare Haunting" is used up for for that 24 hours.

However, RAI based on this tweet from Mike Mearls, that isn't the way it works. The victim only has to be asleep to start the nightmare haunt, but waking doesn't end it.

Alarm Won't Tell You She's coming

I thought Alarm might give you some warning, but its effect appears to be limited to the material plane. (Unless you cast it while in the Ethereal?)

Answer 2

I recommend Leomund's Tiny Hut. It's a 3rd level ritual cast spell for bards and wizards that lasts 8 hours. It is described as:

10-foot-radius immobile dome of force

and among other things, it's description include this:

Creatures and objects within the dome when you cast this spell can move through it freely. All other creatures and objects are barred from passing through it. Spells and other magical effects can't extend through the dome or be cast through it.

In addition, from the DMG page 48, on the Border Ethereal:

A traveler on the Ethereal Plane is invisible and utterly silent to someone on the overlapped plane, and solid objects on the overlapped plane don't hamper the movement of a creature in the Border Ethereal The exceptions are certain magical effects (including anything made of magical force) and living beings.

While some people have expressed concerns about foes burrowing under the dome, it has been clarified that the dome includes a floor.

As long as the hag isn't within the dome's area when the spell is cast, you should have no issue getting an uninterrupted long rest.

Answer 3

As per the RAW description, the Hag can only initiate the contact once every 24 hours. They can't continue to try again if it's interrupted

The ability allows the Hag to can touch someone in the material plane and give them nightmares. If the contact lasts for more than one hour, the creature loses the effect of a long rest. If the creature has Magic Circle or Protection from Good/Evil cast on them, the contact is prevented. The Hag can only attempt this action once every 24 hours.

You are correct in that it will probably be most beneficial to wait until one of the players gets touched by the Night Hag before attempting to do anything about it (this is why you keep watches). Once one of the players starts having nightmares, wake up the Cleric and have them cast Protection from Evil. This will interrupt the Night Hag's ability, and the contact will not have lasted for more than an hour (unless your Cleric is really lethargic).

Since the contact didn't last an hour, the player doesn't lose the effect of a long rest. Furthermore, if the Night Hag wants to try again, she needs to wait until the next day. By that time, if the player begins to be haunted by the Hag then another casting of Protection from Good/Evil will stop it.

The 'Nightmare Haunting' ability includes the initial touch. The Hag can't simply repeat this touch at will because they can only do the touch as part of their once-per-day ability. Once the touch is interrupted or stopped by one of the listed spells, the Hag's ability is over. They will have to utilize the ability again to try again, and they can only try the ability once per day.

Answer 4

Buy a wagon

A party of 5th level adventurers, regardless of their access to magic, very probably have access to some form of overland transport or the funds to purchase some. In order to haunt a character the hag needs to maintain contact, which is much more difficult to do if the target is moving around, particularly if it is moving faster than the hag can, herself, move while ethereal. Sleep in shifts during the day if your DM wont let your horses/oxen/skeletal minions/whatever travel through the night.

If you are travelling long distances over water instead the question is pretty much moot because any decent ocean faring vessel will be travelling faster than the hag pretty much all the time.

Answer 5

Be an elf.

PHB page 23:

Trance. Elves don't need to sleep. Instead, they meditate deeply, remaining semiconscious.

Monster manual page 178:

the hag magically touches a sleeping humanoid on the Material plane

Or be a level 11 monk and already have Tranquility active, and have the Hag fail the wisdom save: PHB page 80:

At the end of a long rest, you gain the effect of a sanctuary spell that lasts until the start of your next long rest

PHB Page 272:

any creature who targets the warded creature with an attack or a harmful spell must first make a wisdom saving throw. On a failed save, the creature must choose a new target or lose the attack or spell.

So if you consider the magical touch to be either an attack or harmful spell, this may work.

Answer 6

Find and kill the hag, seems to be the only real response. All others seem to require a LOT of trouble or luck.