Being lost in a swamp sucks. Trust me, I’ve been there. It’s cold, there’s not nearly enough solid ground, and there are probably alligators a lot closer than you’d like.
So when you see a light in the distance, it’s only natural to think, “Finally! A real person that can help me get out of this mess.”
That’s when the Will o’ Wisp gets you.
This pale ball of light hangs out in swamps, forests, and even urban areas, luring travelers further and further until they are hopelessly lost and fall prey to environmental hazards, are eaten by monsters, or simply freeze to death.
And what do these bright little creatures get? Well, as Chaotic Evil undead, they mostly just like causing problems on purpose, but there’s also the matter of feeding on their victim’s life force as they die…
Did you know that creatures that lure unwary travelers to their doom are common in myths and legends?
Jack o’ lanterns, Hinkypunks, friar’s lantern, Aleya’s, the Chir Batti, Aarnivalkea, and others are all names for the same kind of creature: a mysterious light in the wilderness that leads to doom (or fae gold, depending on the myth in question).
The Wisp’s basic stats are as follows:
- STR 1 (-5), DEX 28 (+9), CON 10 (+0), INT 13 (+1), WIS 14 (+2), CHA 11 (+0)
- AC: 19
- Hit Points: 9d4 (22 average)
- Speed: 0 ft. 50 ft. fly (hover)
- Damage Resistances: Acid. Cold, Necrotic, Fire, Thunder, and nonmagical Bludgeoning, Piercing, and Slashing
- Damage Immunities: Lightning, Poison
- Condition Immunities: Exhaustion, Grappled, Paralyzed, Poisoned, Prone, Restrained, Unconscious
- Proficiency Bonus: +2
- Passive Perception: 10
- Senses: Darkvision 120 ft.
- Languages: The languages it knew when alive
- Challenge Rating: 2
As you can see, Wisps are pretty hard to hit and are about as smart as a mildly smart person. Even if you do manage to hit it, it has a host of resistances to lower the damage. Notably, its strength score is abysmal.
In addition to these general stats, it also has four abilities and three unique actions.
Wisps are unable to hold or wear anything (Ephemeral), but they do have Incorporeal Movement, which allows them to move through objects and creatures as difficult terrain.
They take 5d10 force damage if they end their turn inside an object.
Wisps also glow, shedding bright light in a 5- to 20-foot radius and dim light for an equal number of additional feet. As a bonus action, Wisps can alter this radius.
Also as a bonus action, Wisps can Consume Life, targeting a living creature within 5 feet of it that has 0 hit points and forcing that creature to make a DC 10 Constitution saving throw.
If it fails, it dies, and the Wisp regains 2d6 (10 avg) hit points.
In combat, the Wisp can either Shock its enemies or turn Invisible. Both take an action.
Shock is a melee spell attack (+4 to hit) with a range of 5 feet that does 2d8 (9avg) lightning damage to one creature.
The Wisp and its glow can also turn invisible until it attacks, uses Consume Life, or drops concentration (like a spell).
Behavior & Tactics
The Wisp is a predator that likes to let the environment or others do the actual killing. This simple fact, along with its evil nature, informs much of its behaviors and tactics.
Wisps are built for evasion, stealth, and trickery, and while their high AC and resistances can make them difficult to attack, effectively their low hit points mean that direct combat is so not their style.
Will o’ Wisps are usually cowardly, preferring to use Consume Life on creatures that are already dying or using Shock on creatures who can’t fight back.
They spend their time wandering their environment, feeding on small animals or looking for the lost and the vulnerable.
In Pathfinder, Will ‘o Wisps did not age. Some would organize into societies called “strings” for unknown purposes.
If you had the means or the power, you might compel a Wisp to tell you the secrets it had accumulated over an immortal lifetime.
In 5e, Wisps are the souls of evil creatures who die in situations of great despair; they are undead stuck in the pattern of inflicting their deaths on others.
They seek out opportunities for cruelty and are intelligent enough to leverage their knowledge of the area against even experienced adventurers.
Encountering Will o’ the Wisps
An encounter involving these glow-balls of death is likely to start with a somewhat desperate situation, like either being actually lost in a swamp or simply trying to search a dark and difficult-to-navigate area for some goal or larger enemy.
Whatever the specifics, Wisps try to target people who would react favorably to a distant light, seeking it out rather than hiding from it.
If they can get someone to follow them, they use their invisibility and speed to maneuver to various distant points, encouraging their victims to take convoluted paths that result in total disorientation.
These paths usually end in some terrible place: a sudden cliff that someone might fall off in the fog, an alligator den, quicksand, a patch of poisonous gas, etc.
They might also just bait a desperate person into wandering so far they can never escape the wilderness and die after a few days of wandering in circles, driven mad by a twinkling light that never gets closer.
Wisps are fairly intelligent, and higher-level parties might find themselves hunting down a wisp only to run directly into the lair of a much more powerful monster who’s been expecting them.
Wisps can actually speak, so they can coordinate and plan with allies if they so desire.
However, should their allies be defeated, their Chaotic Evil nature means that they will have no trouble using Consume Life on their former ally and fleeing.
Unless the party is fairly low level or for some reason you’re using a lot of Wisps together as a combat encounter, most Wisps will prefer to lead others into greater danger rather than fighting themselves.
As an encounter, they should be run as a complication to a larger fight rather than serving as the main focus themselves.
Potential allies can be anything from a den of wolves to a local necromancer. However, many people suggest using a Shambling Mound because they can heal from the Wisps’ lightning damage.
Also, the rules are not totally clear about whether a Wisp can end their turn in the space of a creature. It makes sense that it would be possible, and the rules even specify by omission that the Wisp would not take damage.
However, there is a general rule that states a creature cannot willingly end their turn in the same space as another creature.
If you decide this strategy is on the table for Wisps, you might make an encounter consisting of a Shambling Mound with a Wisp hiding inside it, constantly healing the Mound each round with Shock.
Such a symbiotic relationship between even a single Wisp and a Mound could be very dangerous.
If you really want a tough battle, see how many Wisps you can cram into a single Shambling Mound to supercharge it.
When it does go down, your players will be weakened and left facing a swarm of whispering shadows.
Will o’ the Wisp Combat Tactics
Of course, preference and real life often diverge, and a Wisp might easily find themselves in full-on combat. Maybe it thinks it can win, or maybe the party is able to prevent them from simply fleeing.
If a Wisp does have to simply face the party, they’ll likely take full advantage of their maneuverability and incorporeality.
A typical rotation for a wisp might start with it being invisible and then moving toward an enemy and using Shock (with advantage because it started out invisible!). Then the wisp would use its remaining movement to retreat.
This could mean the Wisp simply flies straight up as high as it can to avoid melee, but this is only a last resort.
Using incorporeality, the Wisp can hide inside the hollow spaces of trees or potentially in the underground warrens of rabbits.
A Wisp will likely have taken note of places to hide across its territory, and incorporeality means that options are easy to find.
From total cover, the Wisp will be indestructible. It can use the next round to turn invisible and reposition, setting up another usage of Shock with advantage.
To really increase the survivability of your wisp, you can have it leave combat to find a small animal, shock it, and then use Consume Life on it to heal.
Remember though that a Wisp may not be able to find such sources as easily as hidey-holes, that there will be a limited number of animals close enough, and that the party may be able to prevent it from escaping altogether.
Counter Tactics for Players
Despite the Wisp’s ability to evade damage, players do have access to some effective counters to the Wisp’s tactics.
Firstly, don’t follow strange lights or whispering voices! These are likely Wisps, despite what they might try to tell you.
If you absolutely have to follow these lights, assume you’re walking into a trap. Ready actions, unsheathe weapons and set up buff spells. If you can send advance scouts like familiars or an Arcane Eye.
See Invisibility can be quite effective against Wisps.
In combat, use the rules for damaging objects when a wisp goes to ground. While they have total cover, the object housing them does not. Break that apart to expose the Wisp to attack!
You can also ready attacks while the Wisp is hiding. A round it spends repositioning and turning invisible is a round you can spend getting ready to crush it when it does appear.
Eventually, the Wisp might not be able to hide anywhere, and it could try to flee.
Wisps are pretty much immune to most forms of control, being incorporeal and immune to a variety of conditions, so if it flees, there’s not much you can do.
The best low-level option to lock down a Wisp is the 2nd-level spell Earthbind. This spell targets the Wisp’s Strength save, so it’s almost guaranteed to fail.
It doesn’t impose any conditions on the Wisp that it’s immune to either. Instead, it simply prevents it from flying anywhere, which effectively reduces the Wisp’s speed to 0 since it can only move by flying.
Remember that a Wisp with no movement can still attack, and Earthbind is concentration. Stay out of its range!
Finally, remember to keep your allies above 0HP! This is especially critical with Wisps because of their Consume Life ability.
You might be able to kill a wisp, but it’s better than most creatures at permanently slaying at least one of your own.
Will o’ Wisps: Flavoring and Lore
There are a few straightforward ways to add flavor to Wisps and to make them scary.
In D&D 5e, Wisps are undead, so you might rely on ghost tropes or have them serve (voluntarily or involuntarily) a local necromancer.
They can be powerful allies, are intelligent enough to take complex orders, and can speak to command less intelligent undead.
Swarms of Wisps can also be terrifying to fight, especially if they surround you. As Tiny creatures, you could potentially stack them in a dense cluster.
You can also take advantage of their variable lighting ability. Draw players into a dark space that appears brightly lit, only to have that illumination vanish to a pinprick when it’s revealed to come from a Wisp.
Having players struggle to illuminate their surroundings mid combat to avoid death by disadvantage can add a very real element of panic, especially if they were unprepared for the lights to go out.
However, for maximum flavor and homebrew ideas, I recommend turning to mythology.
There are countless stories of malicious lights in the fog to draw on, each with their own characteristics and personality. You can start looking at some of these tales here for these creatures.
In 3.5/Pathfinder, Will o’ Wisps were aberrations, not undead, and often stories call them fae.
Don’t be afraid to restructure the kind of creature your players face while still keeping the core of a sinister light in the woods, just beyond the effective range of a crossbow.