Nightmare 5e: Stats, Ethereal Stride and the Fiendish Mount

A nightmare is a CR 3 Large fiend (700 XP), a burning black horse with AC 13, 68 hit points, a 60-foot walking speed and a 90-foot fly speed. Alone it is a modest fight: one hooves attack a turn for 20 damage, 7 of it fire. Its real job is carrying someone. It grants its rider resistance to fire, and its Ethereal Stride action takes it and up to three willing creatures to the Ethereal Plane, which makes it the best escape vehicle a CR 3 creature can offer a villain. The 2024 version is nearly identical: its hooves deal 3d6 fire instead of 2d6, and it can hover.

Table of Contents

• •Nightmare Stat Block (2014)
• •Nightmare in the 2024 Rules
• •How the Nightmare Fights
• •The Nightmare as a Mount
• •Running a Nightmare Encounter
• •How Players Beat a Nightmare
• •Nightmare Encounter Ideas
• •Frequently Asked Questions

Nightmare Stat Block (2014)

The SRD 5.1 nightmare.

Compared to the devils and demons it often serves, a nightmare is fragile. It has no Magic Resistance, no saving throw proficiencies, no damage resistances and no condition immunities. Its only defense is fire immunity. It is a plain Fiend with no devil or demon subtype, and it understands Abyssal, Common and Infernal, so it can take orders from either side.

Two details are easy to miss. It has no darkvision, and its Illumination trait sheds bright light for 10 feet and dim light for 10 more. In a dark dungeon it sees by its own glow, and everyone else can see it coming. A nightmare can't ambush anything at night.

Nightmare in the 2024 Rules

Hover is the change that matters. A 2014 nightmare that is knocked prone or has its speed reduced to 0 in the air falls. The 2024 nightmare stays up. If your players like knocking flying mounts out of the sky, the 2014 version is much easier to bring down with a well-timed Command or a grapple.

How the Nightmare Fights

On its own, a nightmare hits with one hooves attack at +6. Against AC 16 that hits on a 10 or better (55%), for about 11 expected damage a turn in 2014 or about 13 in 2024. That's not much at CR 3. A nightmare fighting alone should not stand still and trade blows.

Hit and fly. With a 90-foot fly speed, it can swoop in, kick, and climb back out of reach. Characters without ranged attacks spend the fight watching it circle. It provokes an opportunity attack when it leaves, but with 68 HP it can absorb a few.

Leave through the Ethereal. Ethereal Stride takes its action, so it can't attack on the same turn. Once it and its passengers are on the Ethereal Plane, creatures on the Material Plane can't see or touch them without magic like See Invisibility or truesight (the SRD's Etherealness spell describes how the plane works). The Stride has no listed duration. The nightmare stays until it uses the action again, and it can come back somewhere else.

Return behind the party. Because it can cross back from the Ethereal Plane at will, a nightmare is a good ambusher despite its glow. Returning costs its action, so it steps out of the Ethereal right next to the party's healer and kicks on its next turn. If the healer backs away first, that provokes an opportunity attack.

The Nightmare as a Mount

A Medium or smaller rider can ride a nightmare, because a mount must be at least one size larger than its rider. The mounted combat rules in both SRDs let you control a mount only if it's trained to accept a rider, and SRD 5.1 adds that intelligent creatures act independently. A nightmare has Intelligence 10 and its own evil alignment, so run it as an independent mount: it keeps its own initiative, moves where it wants and attacks on its own turn. The rider still gets a full turn of their own.

For a villain, that means:

• •Two attackers in one space. A rider with a lance or a spell plus the nightmare's hooves, both with 90-foot flight.
• •Fire resistance for the rider. Confer Fire Resistance lets a mounted villain stand in their own fire spells or ride through a burning building.
• •A built-in escape. The rider counts as a willing creature within 5 feet. When the fight turns, the nightmare strides into the Ethereal with its rider and up to two more allies.

Can players get one? Not through Find Steed. The 2014 spell offers a warhorse, pony, camel, elk or mastiff ("your GM might allow other animals"), and the 2024 spell uses its own Otherworldly Steed stat block. A nightmare as a player mount is a DM's reward, not a spell option, and at CR 3 it's a big one for a low-level party.

Running a Nightmare Encounter

A lone nightmare is 700 XP. Using the 2024 budget for four characters:

Under the 2014 Dungeon Master's Guide guidelines (used by our encounter calculator), the nightmare and knight pair counts as 1,400 x 1.5 = 2,100 XP, which is Deadly for four level 4 characters (2,000) and Medium for level 5.

The XP math assumes a fight to the finish. A nightmare that escapes with its rider makes the encounter shorter and the villain recurring. Decide before the fight whether it will run.

How Players Beat a Nightmare

• •Hit its saves. Every save is unproficient: Wisdom +1, Dexterity +2, Charisma +2. It has no Magic Resistance, so Command works well. It understands Common, so "Grovel" knocks it prone. Under the 2024 rules the rider must then make a DC 10 Dexterity save or fall off; under the 2014 rules the rider is dismounted unless they spend their reaction to land on their feet. A 2014 nightmare that goes prone in the air falls.
• •Don't use fire. It is immune, and its rider probably resists it. Cold, lightning, thunder, radiant and force all deal full damage.
• •Stop the escape. Ethereal Stride is an action. Paralysis from Hold Monster, or anything that keeps it Incapacitated, stops the Stride. Banishment against its +2 Charisma save removes the escape route along with the horse.
• •Kill the horse first. 68 HP and AC 13 is less than most riders. Once the nightmare falls, the villain is grounded and the escape is gone.
• •Bring See Invisibility. A nightmare that vanished into the Ethereal is still there. Truesight or See Invisibility lets the party watch where it goes.

Nightmare Encounter Ideas

The rider who never stays. A masked knight has struck three caravans and vanished every time, horse and all, when the guards rallied. The trick is Ethereal Stride. The party needs to stop the horse, not the knight, and the clue is the scorch marks where the hoofprints end.

The stable fire. A nightmare is chained in a noble's stable, a gift from a devil the noble shouldn't be dealing with. Its glow is visible through the slats at night. If someone opens the stall, it burns its way out and goes looking for the noble's daughter, who is the one person it has been told to carry home.

The ghost lantern. Travelers report a floating light moving across the marsh at night, with nothing visible beneath it. It's a nightmare half in and half out of the Ethereal, searching for a rider it lost. Treat it as a hostile creature that could become an ally if the party finds what it's looking for.

Frequently Asked Questions

What CR is a nightmare in 5e?

A nightmare is CR 3 and worth 700 XP in both the 2014 and 2024 rules.

Can a nightmare carry people to the Ethereal Plane?

Yes. Ethereal Stride takes the nightmare and up to three willing creatures within 5 feet of it from the Material Plane to the Ethereal Plane, or back. Unwilling creatures can't be taken along.

Can a paladin's Find Steed summon a nightmare?

Not by the rules as written. The 2014 Find Steed lists a warhorse, pony, camel, elk or mastiff and lets the GM allow other animals. The 2024 spell summons an Otherworldly Steed with its own stat block, which can be a Fiend but uses those statistics, not the nightmare's.

Is a nightmare a devil or a demon?

Neither. It is a Large Fiend with no subtype, neutral evil, and it understands Abyssal, Common and Infernal. It has none of the shared demon or devil defenses like Magic Resistance.

Does a nightmare give its rider fire resistance?

Yes. Confer Fire Resistance lets the nightmare grant resistance to fire damage to its rider. In 2024 the resistance lasts only while the rider is on the nightmare.

Stat blocks: System Reference Document 5.1 (2014) and 5.2.1 (2024), Wizards of the Coast, CC-BY-4.0. Tactics, encounter math and ideas are Loreify's own.