With the publication of Tasha’s Caldron of Everything, the game introduced the concepts of Supernatural Regions to 5th edition Dungeons and Dragons. Areas that have variable and mysterious effects that might be invoked by specific actions or conditions. Within Icewind Dale are localized arcane phenomenon zones said to manifest The Heart of Winter, that is the conjunction of planar regions brought into alignment with Icewind Dale as a function of Auril’s ongoing enchantments. Small clusters of these supernatural phenomenon ebb and flow across the region and it has been growing in frequency, intensity, and size as time progresses.

Arcane scholars suspect casting of spells such as Control Weather, Magnificent Mansion, or similar spells may cause one of these regions to manifest.

The Heart of Winter Supernatural Region

A rustic town forzen in ice.
Image Credit Wizards of the Coast

Consider rolling on the Heart of Winter Magical Effects table when the following circumstances occur in one of these regions.

  • After spending more than an hour resting.
  • A creature is brought to zero hit points.
  • A spell is cast that does Thunder, Cold, or Fire damage.
  • An open flame is produced naturally or by a spell.
  • A creature is Paralyzed

Heart of Winter Magical Effects

d100 Effect
1-5 All flames are extinguished, magical or natural. Any spell producing a flame effect, heat, or controls temperature fails or ends.
6-10 A spell cast that delivers cold damage does not use a spell slot or charge as normal. This can occur only once per person or item in a given day.
11-15 One of the characters in the region must succeed on a DC 15 Wisdom saving throw or be transformed into a Yeti, as if by the polymorph spell. This last for 1 hour or until dispelled.
16-20 Frost and ice begin to cover the area rapidly for 1 minute. For the duration, each round on initiative 20 (losing all ties) one random creature in the area takes 2d4 cold damage.
21-25 Simple or martial weapons in the region that are nonmagical radiate with intense cold. For 1 hour, they become magic weapons that grant +1d4 cold damage in addition to weapon damage.
26-30 Each character in the region is able to cast the Frostbite cantrip as if they were a 1st level caster if they do not already know the spell. The spell save DC is 15.
31-35 Any deep snow in the region acts as Quicksand for the next 10 minutes. See ‘Wilderness Hazards: Quicksand” in the DMG.
36-40 Any humanoid who dies in the next hour rises as a Coldlight Walker, within 2d4 minutes. See Appendix C of Rime of the Frostmaiden.
41-45 One of the characters in the region must succeed on a DC 15 Wisdom saving throw or be transformed into a Chwinga, as if by the polymorph spell. This lasts for 1 hour. See Appendix C of Rime of the Frostmaiden.
46-50 1d10 Ice Mephits appear and immediately attack any humanoids present.
51-55 A deceased humanoid in the region is covered in a sheath of clear magical ice, and is effected by the spell Gentle Repose for the next 10 days or until the ice is broken.
56-60 One random creature in the region receives terrifying visions of a dead frozen world and must succeed on a DC 14 Wisdom saving throw or be frightened and may reroll their saving throw once every minute. The frightened creature will drop any items it is carrying and use the dash action to run in a random direction for the duration. They may repeat the saving throw if they move into obvious danger or are damaged.
61-65 A dense mist permeates the region and when it clears, any creatures and objects caught in the mist find themselves teleported to a random location on top of the Reghed Glacier.
66-70 Extreme cold intensifies in the region and ice begins to form on everyone and everything and a powerful magical wind swirls about. For the next 10 minutes, every creature must make a DC 13 Constitution saving throw or suffer one level of exhaustion. Anyone wearing Cold Weather gear or with resistance to cold may make the saving throw at advantage. Creatures immune to cold damage are also immune to the effects.
71-75 All surfaces become covered in a thick layer of ice for the next 10 minutes, all terrain is considered difficult, and any creature not prone must succeed on a DC 14 Dexterity save or fall prone. Creatures on an incline roll at disadvantage. Creatures with four or more legs make the roll at advantage.
76-78 Creatures in the region lose their ability to speak and don’t need to breath and cannot suffocate for one hour. Spells with a verbal requirement cannot be cast.All creatures gain resistance to fire and have advantage on saves against fire damage for 1 hour.
79-81 Floating shards of ice appear or break away from the ground and begin to swirl through the region for the next minute. On initiative 20 (losing all ties) the ice shards make ranged weapon attack (+6 to hit) against one random creature in the region. On a hit the target takes 3d6 piercing damage.
82-85 The wounds of any creature in the region ice over, stopping any bleeding but preventing them from healing. For the next hour, any spell cast to restore hit points to an effected creature fails, and the caster loses the spell slot. Spells granting temporary hit points are unaffected.
86-90 Rage and anger fills the mind of one random creature in the region for 1 minute. For the duration, the creature has advantage on attack rolls and any attack made against them is at advantage.
91-95 The skin of one random creature turns a deep blue for one hour, and they gain immunity to cold damage.
96-00 The eyes of one random creature turn completely blue, for the next hour they have darkvision. Creatures already possessing darkvision have their range doubled for the duration. Additionally they appear invisible to any creature with darkvision for the duration.