D&D 5e is light on the number of diseases they have available, so I developed a series of tables that creates random, generic diseases. The main part of this table was actually taken from the AD&D Dungeon Master’s Guide, but it works well for this purpose. This table isn’t particularly flavorful about the disease, so it doesn’t work well as a story element, but as a game mechanic it at least gives some more information for a random disease and lets you come up with one off-the-cuff.
The generator determines how the disease is caught and transmitted, so if it’s contagious the other players ought to be careful. Then you determine what part of the body the disease affects. Once you know that, you know what ability scores it weakens. Once you know the disease’s occurrence and severity, you can make a roll at each time interval. On a failed save, the prior-determined ability scores are affected according to the severity.
The duration of the disease determines how long it takes for the disease to pass. Some diseases will eventually kill the creature, while others might go away on their own. There is also a table for treating the disease, which here grants advantage on CON saves for the disease. You can also use it as a jumping-off point for coming up with a way to completely cure the disease, like finding rare reagents for a spell or potion or finding a unique herb. Of course, a Cure Disease spell will always come in handy.
D&D 5e Random Disease Generator
Transmission: Roll 1d6 to determine how the disease is initially caught.
1: Contact - Merely touching an infected creature can put you at risk of infection. Common for skin conditions and STDs.
2: Fluid Contact - Only contact with infected bodily fluids can spread the disease, so intercourse, blood, spit, or bodily waste can all be contagious.
3: Inhaled - Can some from being near spoiled food or festering filth or rancid corpses, and is transmitted through the breath of a diseased person. Common for throat/nose diseases.
4: Ingested - Diseased or spoiled food, usually a parasite of some sort.
5: Injury - Usually from diseased monsters like rats or otyughs.
6: Genetics - Sometimes a disease unfortunately just manifests as a result of a genetic mutation. Such a disease is always considered noncommunicable.
Contagiousness:
Roll 1d6 to determine how contagious the disease is. Whenever a creature comes in contact with a disease, have them make a CON save to resist catching it. The DC is based on the contagiousness as shown below.
1: Noncommunicable - The disease is not contagious once contracted.
2-3: Weakly Contagious - CON DC 8
4-5: Somewhat Contagious - CON DC 11
6: Highly Contagious - CON DC 15
Disease Type: Roll 1d100 to determine the part of the body that the disease attacks. The ability scores that relate to the location of the disease are described are affected by the severity of the disease, as shown in the severity table.
Occurrence: Roll 1d6 to determine how frequently the disease’s effects occur. Roll a CON saving throw at each interval. On a failed save, the diseased creature is affected as determined by the severity as shown in the severity table.
1-2: Chronic - Roll a CON saving throw each week.
3-6: Acute - Roll a CON saving throw each day.
Severity: Roll 1d20 to determine the severity of the disease. The listed effect occurs with each interval listed in the Occurrence roll. This determines how the disease affects the ability scores associated with it (see Disease Type). The only exceptions are diseases of the eyes and ears.
1-2: Terminal - Each failed CON save reduces relevant ability scores by 1. When one reaches 0, you die. Eyes/Ears: You become permanently blind/deaf.
3-10: Severe - Each failed CON save reduces relevant ability scores by 1, on a successful save, heal them by 1. Eyes/Ears: You become blinded/deafened for the duration of the disease.
11-20: Mild - Each failed CON save reduces applies disadvantage on rolls involving the relevant ability that period. Eyes/Ears: You gain disadvantage on Perception checks involving sight/sound for the duration of the disease.
Duration: Roll 1d20 to determine how long it takes for the disease to pass through one’s system naturally.
1: Permanent: Make a CON saving throw
2-5: 1d6+1 Months
6-10: 1d4+1 Weeks
11-20: 1d10+1 Days
Treatment: Roll 1d12 to determine how to properly treat the disease. Each CON save is made with advantage if the creature is being treated properly between each CON save. This is assuming divine magic cannot cure the disease outright with a Cure Disease spell. A Medicine check will accurately diagnose the disease and its treatment, usually with a DC of 15 or higher.
1: Heal Naturally - rest, drink plenty of fluids, and hope it goes away on its own.
2: Herbology - mixing of medicinal herbs. Requires a WIS check with a Herbalism Kit with a DC equal to the disease’s Severity DC, otherwise it worsens the disease by acting as one failed saving throw.
3: Alchemy - Mixing of chemicals to help cure the disease. Requires an INT check with Alchemist’s Supplies with a DC equal to the disease’s Severity DC, otherwise it worsens the disease by acting as one failed saving throw.
4: Arcane Magic: Contagion - You combat the disease with one of your own; requires an Arcana check with a DC equal to the disease’s Severity DC, otherwise it worsens the disease by acting as one failed saving throw.
5: Arcane Magic: Necrotic Damage - You kill off the disease by expending at least a level 3 spell slot on a spell that deals necrotic damage; requires an Arcana check with a DC equal to the disease’s Severity DC, otherwise it harms the target.
6: Arcane Magic: Poison Damage - You kill off the disease by expending at least a level 3 spell slot on a spell that deals poison damage; requires an Arcana check with a DC equal to the disease’s Severity DC, otherwise it harms the target.
7: Divine Magic: Lesser Restoration
8: Divine Magic: Greater Restoration
9: Divine Magic: Cure Wounds
10: Divine Magic: Remove Curse
11: Divine Magic: Protection from Poison
12: Surgery - Requires a Medicine check to perform with a DC of about 15 if external or at least 20 if internal. A failed save worsens the disease by acting as one failed saving throw.
Concept: That scene in every 90s high school movie where someone shows the new kid around the cafeteria (”that table is the nerds, those are the jocks, the goths, the cheerleeders” etc) except it’s a medieval tavern and each table has a different d&d class.
“Look, newbie, where you sit in the tavern is crucial because you got everybody there. You got your NPCs, Rangers, Sorcerers, Warriors, Warlocks, Druids, Barbarians, Monks, the Greatest People You Will Ever Meet (Bards) and The Worst: beware of the Paladins.”
“Where are the Rogues?”
The other student points up and there within the shadows on the ceiling, is an upside down table with all the Rogues.
DM gave my character a ring that allowed me to change a letter or drop a letter of a spell I could cast. The spell will reflect its new name. So a spell like Fireball would become Firball (sharp pine needles explode in a radius), Blur became Slur (if cast on a magic user, they can’t use spells with verbal components), Slow becomes Plow (till a field in a minute), etc.
I’m looking down my list of spells after I get the ring to see what mayhem I can cause & I don’t make it past the cantrips before I start laughing so hard I start to cry. I look up at the DM with a huge grin on my face.
“From now on I will only be casting Vicious Cockery at my enemies. It still does 1d4 psychic damage, but instead of insulting them, a disembodied dick smacks them in the face.”
Don't give up. Unless you have to for a little while. Then don't panic. CONTAINS: Star Trek, Dungeons and Dragons, Critical Role, History, Current Affairs, Space, Cats, and Etc. Adult.
