Expanded Diseases Rules
Disease Mechanic
Depending on the Disease, you may not need to roll a save specified by the Disease to avoid contracting it. When a creature is subjected to an event or condition that would risk exposing them to the Disease, it will begin incubating in them without any need to roll a save. At the end of the incubation period, the creature rolls a save against the Disease DC. If you are successful in the save, the disease won't take hold or would have diminished during incubation. If the Disease has multiple Stages, it start at Stage 1. A save should only be made upon contact if the effect of the disease is immediate. If the disease is spread through physical contact, like a bite or an attack, then the disease should only start incubating if the target has been hit by the attack a number of times equal to their con mod (with a minimum of 1).
One option to avoid metagaming is for the DM to keep as little information from the Player as possible, only to tell them to prompt the necessary save, but not to tell what for or whether they succeeded or not. Do, however, inform the player when their character is sick, preferably by describing their current state of being and how it affects actions and rolls that the disease specifies as being detrimental to. Such a runny nose, itching, headaches, coughs, and other forms of symptoms may give a clue.
Treating Disease with Medicine and Rest.
Time, Medicine, Food, and Rest are usually the best way to combat the illness. There is, however, a lack of rules to explain how you would combat Diseases and similar ailments, outside of "apply magic to remove" or take a chance after a long rest. There are, however, several nonmagical means to combat your illness.- You can use items that have medicinal properties to add a bonus to your next Disease save. Keep in mind that if you take multiple medicinal items, you only get the benefit of the one that has the highest modifier.
- While you are affected by a Disease, each hour of non-strained activity you take in a day, you add a +1 modifier to your next Disease Save. Each rough activity applies a -1 to your save, however.
Treating Disease with Magic
The biggest issue that needs addressing is Magical Healing. Because you can slap on any curing spell and have the illness gone in an instant. This renders Diseases all the way from Lame to insignificant. Not to mention the skill Medicine, the very skill that should, in theory, be very useful in this sort of practice, is rendered almost pointless due to the non-factor of Diseases. This rule is meant to fix and expand the function of magical healing.
When you cast Healing Magic such as Lesser Restoration and Lay on hands to cure diseases or any similar healing spell, you are given two options, to Suprees or Cure the disease.
- Cure:The caster must make an ability check with their spellcasting modifier, or the target makes a save against the DC of the disease. On a success, the disease is cured, but on a failure, nothing happens as the magic is wasted. If the caster doesn't know what's ailing the person prior to casting, the roll is made with disadvantage. Since they are effectively brute-forcing a cure with magic. If the Disease is incubating, it's automatically removed without any roll required.
- Suprees: The effect of the Disease suppresses for the duration of 12 hours, and any detrimental effect on a failed save that would result in the condition worsening is negated. Casting spells that cure disease at a higher level adds +1 to the next saving throw against disease for each level above the spell’s standard level. If the creature is affected by a magical disabling effect, such as the spell dispel magic, the Suppression effect is removed.
