System Reference Document 5.2.1
194
Magical Contagions
Alchemists, potion brewers, and areas of wild magic 
are credited with creating the first magical con -
tagions. 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 suc -
cessful 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 conta-
gions can work. Feel free to alter the saving throw 
DCs, effects, and other characteristics of these con -
tagions 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 crea-
ture 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 suc -
ceeds automatically.
 Fighting the Contagion. At the end of each Long 
Rest, an infected creature makes a DC 13 Constitu -
tion 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 Consti -
tution saving throw or also become infected with 
the contagion. On a successful save, the Humanoid 
can’t catch the contagion from that particular in -
fected 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 otyu -
ghs 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 be -
come infected with Sewer Plague. A creature suffers 
the following effects 1d4 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 Exhaus -
tion levels, finishing a Long Rest neither restores 
lost Hit Points nor reduces the creature’s Exhaus -
tion level.
 Fighting the Contagion. Daily at dawn, an in -
fected creature makes a DC 11 Constitution saving 
throw. On a failed save, the creature gains 1 Ex -
haustion level as its fatigue worsens. On a success -
ful 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 immedi -
ately. A character who is proficient with an Herbal -
ism 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 oint -
ment 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 con -
tagion. On a successful save, the Humanoid can’t 
catch the contagion from that particular infected 
creature for the next 24 hours.