Curses and Magical Contagions
A curse is a magical burden that lasts for a specified time or until it is ended by some means. A magical contagion is an adverse effect of magical origin that is contagious by definition. The following sections discuss curses and magical contagions in detail.
Curses
A curse typically takes one of the forms detailed below.
Bestow Curse
The simplest curses are created by the Bestow Curse spell. The effects of such curses are limited and can be ended by the Remove Curse spell. Bestow Curse provides useful benchmarks for gauging the potency of other curses. A curse that lasts for 1 minute equates to a level 3 spell, while one that lasts until dispelled equates to a level 9 spell.
Cursed Creatures
Some monsters are associated with curses, whether as part of their origins or due to their ability to spread curses-werewolves being a prime example.
You decide how a spell like Remove Curse affects a creature with accursed origins. For example, you might decide that a mummy was created through a curse and it can be destroyed permanently only by casting Remove Curse on its corpse.
Cursed Magic Items
Cursed magic items are created deliberately or originate as the result of supernatural events. Such items are detailed in "Magic Items."
Narrative Curses
A curse might manifest during an adventure when a creature's violation of a taboo warrants supernatural punishment, such as breaking a vow, defiling a tomb, or murdering an innocent. Such a curse can have any effects you design, or it might be a customized version of another type of curse discussed in this section. A creature affected by such a curse should know why they're being punished and be able to learn how to end their curse, likely by symbolically righting the wrong they committed. How a spell like Remove Curse affects a curse that's part of your adventure is up to you-the spell might merely suppress the effects of the curse for a time. Regardless, narrative curses should feel like rare, potent magic rooted in the lore of your campaign.
Environmental Curses
Some locations are so suffused with evil that anyone who lingers there is burdened with a curse. Demonic Possession is one example of an environmental curse. Demonic Possession. Demonic Possession arises from the chaos and evil of the Abyss and commonly besets creatures that interact with demonic objects or linger in desecrated locations, where demonic spirits await victims. A creature that becomes the target of Demonic Possession must succeed on a DC 15 Charisma saving throw or be possessed by a bodiless demonic entity. Whenever the possessed creature rolls a 1 on a D20 Test, the demonic entity takes control of the creature and determines the creature's behavior thereafter. At the end of each of the possessed creature's later turns, the creature makes a DC 15 Charisma saving throw, regaining control of itself on a success. After finishing a Long Rest, a creature with Demonic Possession makes a DC 15 Charisma saving throw. On a successful save, the effect ends on the creature. A Dispel Evil and Good spell or any magic that removes a curse also ends the effect on it.
Magical Contagions
Alchemists, potion brewers, and areas of wild magic are credited with creating the first magical contagions. An outbreak of such a contagion can form the basis of an adventure as characters search for a cure and try to stop the contagion's spread.
Rest and Recuperation
If a creature infected with a magical contagion spends 3 days recuperating-engaging in no activities that would interrupt a Long Rest-the creature makes a DC 15 Constitution saving throw at the end of the recuperation period. On a successful save, the creature has Advantage on saving throws to fight off the magical contagion for the next 24 hours.
Example Contagions
The following examples show how magical contagions can work. Feel free to alter the saving throw DCs, effects, and other characteristics of these contagions to suit your campaign.
Cackle Fever
Magical Contagion Cheaply made potions and elixirs are sometimes tainted by Cackle Fever, which affects Humanoids only (gnomes are strangely immune). A creature suffers the following effects 1d4 days after infection:
Fever. The creature gains 1 Exhaustion level, which lasts until the contagion ends on the creature. Uncontrollable Laughter. While the creature has the Exhaustion condition, the creature makes a DC 13 Constitution saving throw each time it takes damage other than Psychic damage. On a failed save, the creature takes 5 (1d10) Psychic damage and has the Incapacitated condition as it laughs uncontrollably. At the end of each of its turns, the creature repeats the save, ending the effect on itself on a success. After 1 minute, it succeeds automatically. Fighting the Contagion. At the end of each Long Rest, an infected creature makes a DC 13 Constitution saving throw. After the creature succeeds on three of these saves, the contagion ends on it, and the creature is immune to Cackle Fever for 1 year. Spreading the Contagion. Any Humanoid (other than a gnome) that starts its turn within a 10 -foot Emanation originating from a creature infected with Cackle Fever must succeed on a DC 10 Constitution saving throw or also become infected with the contagion. On a successful save, the Humanoid can't catch the contagion from that particular infected creature for the next 24 hours.
Sewer Plague
Magical Contagion Fouled potions and alchemical waste can give rise to Sewer Plague, which incubates in sewers and refuse heaps and is sometimes transmitted by creatures that dwell in such areas, including otyughs and rats. Any Humanoid that is wounded by a creature that carries the contagion or that comes into contact with contaminated filth or offal must succeed on a DC 11 Constitution saving throw or become infected with Sewer Plague. A creature suffers the following effects 1 d 4 days after infection: Fatigue. The creature gains 1 Exhaustion level. Weakness. While the creature has any Exhaustion levels, it regains only half the normal number of Hit Points from spending Hit Point Dice. Restlessness. While the creature has any Exhaustion levels, finishing a Long Rest neither restores lost Hit Points nor reduces the creature's Exhaustion level.
Fighting the Contagion. Daily at dawn, an infected creature makes a DC 11 Constitution saving throw. On a failed save, the creature gains 1 Exhaustion level as its fatigue worsens. On a successful save, the creature's Exhaustion level decreases by 1 . If the creature's Exhaustion level is reduced to 0 , the contagion ends on the creature.
Sight Rot
Magical Contagion Any Beast or Humanoid that drinks water tainted by Sight Rot must succeed on a DC 15 Constitution saving throw or have the Blinded condition until the contagion ends.
Fighting the Contagion. Magic such as a Heal or Lesser Restoration spell ends the contagion immediately. A character who is proficient with an Herbalism Kit can use it to create one dose of nonmagical ointment, which takes 1 hour. When applied to the eyes of a creature suffering from Sight Rot, the ointment suppresses the contagion on that creature for 24 hours. If the contagion is suppressed in this way for a total of 72 hours (requiring three doses and applications of the ointment), the contagion ends on the creature.
Spreading the Contagion. Any Humanoid that makes skin contact with a creature infected with Sight Rot must succeed on a DC 15 Constitution saving throw or also become infected with the contagion. On a successful save, the Humanoid can't catch the contagion from that particular infected creature for the next 24 hours.
Deep Water
Swimming through deep water (more than 100 feet deep) presents additional challenges because of the water's pressure and cold temperature. After each hour of swimming in deep water, a creature that lacks a Swim Speed must succeed on a DC 10 Constitution saving throw or gain 1 Exhaustion level.
Extreme Cold
When the temperature is 0 degrees Fahrenheit or lower, a creature exposed to the extreme cold must succeed on a DC 10 Constitution saving throw at the end of each hour or gain 1 Exhaustion level. Creatures that have Resistance or Immunity to Cold damage automatically succeed on the save.
Extreme Heat
When the temperature is 100 degrees Fahrenheit or higher, a creature exposed to the extreme heat and without access to drinkable water must succeed on a Constitution saving throw at the end of each hour or gain 1 Exhaustion level. The DC is 5 for the first hour and increases by 1 for each additional hour. Creatures wearing Medium or Heavy armor have Disadvantage on the save. Creatures that have Resistance or Immunity to Fire damage automatically succeed on the save.
Frigid Water
A creature can be immersed in frigid water for a number of minutes equal to its Constitution score before suffering any ill effects. Each additional minute spent in frigid water requires the creature to succeed on a DC 10 Constitution saving throw or gain 1 Exhaustion level. Creatures with Resistance or Immunity to Cold damage automatically succeed on the save, as do creatures that are naturally adapted to living in ice-cold water.
Heavy Precipitation
Everything within an area of heavy rain or heavy snowfall is Lightly Obscured, and creatures in the area have Disadvantage on all Wisdom (Perception) checks. Heavy rain also extinguishes open flames.
High Altitude
Traveling at altitudes of 10,000 feet or higher above sea level is taxing for most creatures because of the reduced amount of oxygen in the air. Each hour such a creature spends traveling at high altitude counts as 2 hours for the purpose of determining how long that creature can travel (see "Travel Pace").
Creatures can become acclimated to a high altitude by spending 30 days or more at this elevation. Creatures can't become acclimated to elevations above 20,000 feet unless they are native to such environments.
Slippery Ice
Slippery ice is Difficult Terrain. A creature that moves onto slippery ice for the first time on a turn or starts its turn there must succeed on a DC 10 Dexterity saving throw or have the Prone condition.
Strong Wind
Strong wind imposes Disadvantage on ranged attack rolls with weapons. It also extinguishes open flames and disperses fog. A flying creature in a strong wind must land at the end of its turn or fall.
A strong wind in a desert can create a sandstorm that imposes Disadvantage on Wisdom (Perception) checks.
Thin Ice
Thin ice has a weight tolerance of 3d10 \times 10 pounds per 10 -foot-square area. Whenever the total weight on an area of thin ice exceeds its tolerance, the ice in that area breaks. All creatures on broken ice fall through. Below the ice is frigid water (see "Frigid Water" above).