Scale Sickness/Dragon Lycanthropy (5e Disease)
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Scale Sickness/Dragon Lycanthropy
This incredibly infectious plague is a rampant, dragon version of lycanthropy, though its common name is Scale Sickness. Individuals only know it's Dragon Lycanthropy on a successful DC 20 Arcana, History, Nature, Religion, or Medicine check. History and Religion checks might fail if the DM decides it's not been in historical documents or religious doctrine in the past on their world.
Only Humanoids that aren't Dragonborn or Half-Dragons and the like (Due to their already draconic nature) can be infected. Infection occurs when coming into contact with infected matter, including the air within 20 feet of an infected individual, matter they have touched within the last 6 weeks, or any infected individuals that don't become Dragon Lycanthropes. If any of these occur, the individual must roll a DC 20 Constitution saving throw or become infected with the disease. If they have any open wounds at that moment, they automatically fail the saving throw. Any infected only shows symptoms of Scale Sickness if their Constitution score is 18 or less. Anyone with a Constitution score of 19 or higher instead develops Dragon Lycanthropy, noted in the Homebrew Rule Dragon Lycanthropy (5e Variant Rule). Clerics and Paladins of a Dragon-deity are immune to Scale Sickness, and only develop Dragon Lycanthropy if their deity wishes it. Additionally, those with class or race features that give them Draconic properties but don't inherently make them dragons (Like Draconic Bloodline Sorcerers) are also afflicted differently, as shown in the Homebrew Rule, Dragon Lycanthropy (5e Variant Rule). The initial symptoms of Scale Sickness are inherently related to dragon type and always begin 5+Constitution Modifier minutes after infection. Infected always contract the same type of Scale Sickness that the bearer had. Chromatic and Metallic infection is possible, the differences detailed later.
Those infected with Fire versions develop a headache which causes them to become Paralyzed and gives them an Exhaustion Point that cannot be removed until the aliment is cured.
Those infected with Cold versions develop a constant cough that disables speaking and keeps their concentration, preventing them from using concentration on anything else and from using the Rage class feature. The constant cough can make the infected cough up infected blood. Anyone exposed to infected blood instantly becomes infected (No save) if they consume it or it touches an open wound.
Those infected with Lightning versions are blinded and begin to fall into fits of horrible pain that prevents them from taking any actions when they occur. They occur at random after the first one, and last 3d20 minutes each. The pain does not inherently cause injury, but the constant pain can cause muscle contraction and movement that injures the infected if they aren't prevented from doing so. Each time an injury occurs from this, it typically occurs by 1+ the infected individual's Strength modifier bludgeoning damage, as if they hit themselves with an unarmed attack. Because this isn't intentional, ignore class features the creature might have that change the damage of their unarmed strikes, although racial traits that do so naturally still apply. Depending on the situation, the random movement may cause impacts that lead to further injury, such as an arm jerking into a fire pit, or a muscle contorting so far that it breaks the bone. These special situations must be handled by the DM, since making rules for every scenario would be far too tedious for any one person.
Those infected with Acid versions take 1d4 Acid damage every 5 minutes that cannot be healed by a short or long rest. This slowly melts them, and if allowed to kill them, melts their body's core, making magic that revives them require being able to make a new body; or at the very least, can replace the whole of the chest of the body and all its organs.
Those infected with Poison versions become Poisoned (Revolutionary, I know) for the duration of the disease and must make a roll on the Long-Term Madness table each hour they are infected. Each new roll on the Long-Term Madness table replaces the previous effect, though the last one they have once cured (Assuming it isn't deadly) lasts as long as it normally would unless removed.
Scale sickness for homebrew dragon types may exist, but the effects of which would have to be customized since there is a lot of homebrew dragons and I'm lazy. So there.
In addition to the above effects, ANY type of Scale Sickness leads to the following additional effects:
1d8+Constitution Modifier hours after infection, scales of the appropriate dragon type begin to painfully grow through random points on the skin of the infected. When this occurs, the creature loses 1 point of Constitution until cured, and if the type is of a Metallic Dragon (Gold, Bronze, etc.) then the infected also becomes Poisoned until the infection is cured. More scales appear over time, leading to worse effects. For each day after this effect occurs, the infected gain 1lb of scales and lose 1 point of Constitution. If this brings their Constitution score down to zero, they drop to zero hit points, are destabilized (Death Saves required) and cannot be stabilized while they are infected. The additional weight counts against their Encumbrance, and while infected, Encumbrance is calculated purely in 1X their Strength score in lbs. The coat of scales will stop getting heavier when it weighs 15lbs, and the infected will not lose further points of their Constitution score if this occurs. The infected must roll a Constitution saving throw each hour they are conscious (And a single roll for when they are naturally asleep) while the coat of scales weighs more in pounds than their Constitution score to determine if they can hold back the weight from crushing them, taking 6d6 bludgeoning damage on a failure and half as much on a success. This damage cannot be healed by a short or long rest, though magical healing still works.
DM Note: See, I told you it wasn't awesome. In case it hasn't been noticed though, keep in mind that Scale Sickness from Metallic Dragon Lycanthropy is automatically worse than that of Chromatic Dragon Lycanthropy, due to the metal poisoning that accompanies it. Because of this, some interesting storytelling involving the interplay between Metallic Dragons and the worse forms of Scale Sickness can be made. For example, commoners may mistakenly believe that a Metallic Dragon or them in general could be the cause of an outbreak, or worse yet, that Bahamut himself brought it upon them (Which could be propaganda spread by followers of Tiamat). The story possibilities are as large as your imagination.
Variant Rule: Alkali Fever
If you want to make metallic forms even worse, I more recently made a page called Alkali Fever (5e Disease) that you can use in place of the more tame +poison effect. In such a case, they are treated as within the area of effect for a source of Alkali Fever as long as they have a coat of metal scales, even after being cured of the Scale Sickness.
Anything that can cure Lycanthropy can cure Scale Sickness before scales begin to form. However, once the first scale forms, curing becomes impossible by those lesser means. Greater Restoration can revert Scale Sickness back to initial symptoms before the Deeper Plague, and Wish can kill the lycanthropy completely (And instantly, destroying any coat of scales the victim has from the aliment). The DM can also designate further cures, including mundane ones, though knowledge of such cures is rare or nonexistent (Depending on the DM's storytelling choice) and finding them or becoming powerful enough with magic to administer them can be arduous and might require questing. Otherwise, those infected with Scale Sickness cannot naturally end it. Additionally, the scales that give the Disease its name destroy the skin of the individual. If cured after they have a coat of scales that weighs at least 5lbs (Which would cover 50% of the skin at this point, with 10lbs covering the whole skin layer and additional growth being in the existing scales) only recover one hit point each long rest until they reach at least 90% of their maximum hit points, however magical healing can be applied to expedite recovery. Until they recover completely, they have disadvantage on all Constitution checks and saving throws.