AC 17
HP 28 (8d6; bloodied 14)
Speed 0 ft., fly 50 ft. (hover)
Proficiency +2; Maneuver DC 17
Damage Immunities lightning, poison
Damage Resistances acid, cold, fire, necrotic, thunder; damage from nonmagical weapons
Condition Immunities fatigue, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 120 ft., passive Perception 12
Languages the languages it knew in life
Conductive. Each time a creature touches the will-o’-wisp or hits it with a metal melee weapon for the first time on a turn, the creature takes 7 (2d6) lightning damage. This trait doesn’t function while the will-o’-wisp’s glow is extinguished.
Insubstantial. The will-o’-wisp can’t pick up or move objects or creatures. It can move through creatures and objects. It takes 5 (1d10) force damage if it ends its turn inside an object.
Treasure Sense. The will-o’-wisp knows the location of coins, gems, and other nonmagical wealth within 500 feet.
Undead Nature. A will-o’-wisp doesn’t require air, sustenance, or sleep.
ACTIONS
Shock. Melee Spell Attack: +4 to hit, reach 5 ft., one target. Hit: 10 (3d6) lightning damage. The will-o’-wisp can’t make this attack while its glow is extinguished.
BONUS ACTIONS
Illumination. The will-o’-wisp alters the radius of its glow (shedding bright light in a 5- to 20-foot radius and dim light for the same number of feet beyond that radius), changes the color of its glow, or extinguishes its glow (making it invisible ).
Combat
The will-o’-wisp attacks, turns invisible, and then moves to safety. On its next turn it moves to melee range, turns visible, and attacks. It repeats this pattern. The will-o’-wisp fights only to preserve its treasure. It may retreat to summon allies or otherwise cause trouble.
Legends and Lore
With an Arcana or Religion check, characters can learn the following:
DC 10 Undead spirits known as will-o’-wisps take the form of glowing spheres of light to lead unwary travelers astray.
DC 15 Will-o’-wisps have no physical bodies, making them insubstantial and immune to most forms of damage.
DC 20 Every will-o’-wisp guards a secret cache of wealth that it coveted in life. The path to a will-o’-wisp’s treasure, however, is fraught with peril.
Will-o’-wisps, also called corpse lights, are glowing balls of light that appear at night and lure travelers into danger. Seen from a distance, they resemble beckoning lanterns or cheery cottage windows—but those who pursue them are more likely to lose their lives than find their way.
Markers of Hidden Treasure. Will-o’-wisps are the undead spirits of misers who couldn’t bear to leave their worldly wealth behind as they passed on to the afterlife. They haunt their former hoards, guarding secret caches or traveling a lonely circuit between buried treasures.
Some foolish souls may try to follow a wisp to its treasure trove. Such pursuits are dangerous: a will-o’-wisp, cunning in the defense of its hoard, travels over precipices, traps, and other hazards even when it believes itself alone. If a will-o’-wisp becomes aware of pursuers, it chooses an even deadlier route.
Malevolent Spirits. Will-o’-wisps have few thoughts beyond preserving and adding to their hoards. They rarely attack creatures directly except to defend their treasure, but they may lead travelers astray in order to acquire their wealth. Some will-o’-wisps lure creatures into bogs and quicksand: an enemy caught in a mire is self-burying treasure. Other will-o’-wisps prefer to lead creatures into the clutches of unintelligent monsters, gloating over the coins that accumulate in the monster’s lair. Still others, the undead shades of greedy pirates, appear amidst storms, shining deceptive signals to lead ships onto deadly shoals.
Wilderness and Underground Behavior
1-3 On its way to a treasure cache; if it notices travelers, it leads them through dangerous obstacles (monsters, bogs, traps, cliffs)
4 Attacks travelers directly: tries to do so in an area of standing water (it gains advantage on on shock attacks made against creatures in the water)
5 Hovering above its most recent victim
6 Circling a hazard such as a sinkhole, hunting pit trap, or pit trap
Sea Behavior
1 Masquerading as the signal lights of a ship, trying to lead vessels onto a dangerous reef
2 Blinking like a lighthouse beacon
3 Following a ship, pointing it out to enemies
4 Clinging to a mast, shocking anyone who climbs it
1 A distant flicker of blue light
2 Cheery orange light, like a bobbing lantern, on the horizon
3 A distant steady light
4 A flash like a bolt of lightning splits the sky
Will-o’-wisps can be found at night in deserted and dangerous places, particularly swamps and bodies of water.
CR 0–2 will-o’-wisp
Treasure 150 gp, 400 sp, 500 cp, potion of greater healing , eyes of the eagle
CR 3–4 2 will-o’-wisps ; will-o’-wisp with 1 or 2 ghouls or shadows
Treasure 350 gp, 3 jasper gemstones (50 gp each), spell scroll of locate object , 1 shortsword (made of obsidian; doesn’t conduct electricity)
CR 5–10 will-o’-wisp with flesh guardian , owlbear , or shambling mound
Treasure 50 pp, 600 gp, deeds of ownership to property in slums or ruins, unsigned last will and testament, 3 potions of superior healing , ring of swimming