We all know that liches and red dragons are good at killing characters. We also know that Goblins and Trolls are excellent for harassing them, but these encounters, while fun and exciting (sometimes) are not the only dangers that threaten the adventurer. Many DMs simply forget about the smaller dangers, a species of monster that plagues mankind even to this day! Microscopic little critters that get inside of us and just make general havoc! Yes friends, I’m talking about disease, and other parasitic nasties that can make an adventurer afraid to lace up his armor!

There are two ways to go about this, the hard way, or the easy way, and I don’t know about you, but easy sounds pretty god damned good to me! We won’t be messing around with specific types, we aren’t Doctors here, we just want to have a good time ruining a PC’s day. We’ll be focusing more on general terms, then on any real accuracy. We’ll look at general maladies, and how they effect the game, not to mention the players chances of getting to enjoy one!

Contracting a Disease

Remember that cool calendar we were suppose to be using? You’ll need it for this, because we are going to want to check to see if our PCs have caught a disease once a week. You really have to realize just how filthy and scummy everything was back in the day. Outdoor markets, no garbage pickups, horse shit everywhere, people dumping their piss right out of the window and into the street, running water was unheard of, clean water was even more rare, Arid Extra Dry won’t be invented for hundreds of years!!! Our past was very very stinky. And with stink come germs and vermin. We’ll be checking for disease once a month, but if the conditions are perfect, if the weather is good and hot, the air is moist, and/or you're in a filthy crowded area, we’ll be checking for disease every week.

We also need to check whenever a character has been exposed to a carrier in a way that would allow the disease to travel into him. Carriers can be human, animal, bugs, food, drinks, vermin, dirt, filth, anything that you think could contract an illness!

Contracting Parasites

We’ll be checking for Parasites each month, too. This is a separate roll, because, honestly, we want to share the love! And what better way to show somebody that you care, then by infesting them with parasites? Again, if the conditions for parasites are good, living in filthy conditions that are warm or hot and moist, we’ll up the parasitic ante up to once per week. We’ll also check it each and every time that they unwittingly expose themselves to a source, such as swamp water, manure, raw meat, or my drunk uncle Phil.

Chance of Contracting a Disease

Base Chance...................................................................2%
Modifiers

Currently diseased or infested with parasites.................+1%
Crowded.................................................................+1%
Filth.......................................................................+1%
Character is old........................................................+2%
Environment.............................................................+2%
Hot & Moist Climate...................................................+2%
Character is venerable...............................................+5%
Exposure to carrier of communicable disease..................+10%
Cool weather or climate............................................. -1%
Cold weather, high mountains..................................... -1%
Shipboard after being at sea 2 weeks............................-2%