Thursday, 6 August 2015


I’m working on a new set of House Rules to be bound in book form soon, and spicing it up with a revamped selection of medieval afflictions that our party has to take care to avoid catching. For simplicity’s sake, I’ve been rolling a d20 every time they’ve been exposed to an infectious agent, and having them afflicted if the roll is above their CON score. I’m working on some tables for modifiers, but we’ll continue to play by the simple rules until I’m satisfied that the alternative is an improvement.

The Ague.  A parasitic disease contracted in damp environments such as swamps and wetlands. Onset in 6d6 days. Shaking, chills, severe headache and weakness (STR -2, INT -2, DEX -4, THAC0 and HP reduced by half) persist for 2d6 hours, followed by profuse sweating, after which all ability scores temporarily return to normal. Attacks return every 48 or 72 hours reducing ability scores again. If untreated after second day, save vs. death or lapse into coma. Roll same save once per day thereafter to recover from coma (or lapse into coma if not comatose). Persists 3d6 weeks if untreated. 

Black Plague.  Characters need worry about this disease only when cases have been sighted or reported in the local area. Onset occurs in 1d6 days. Bubonic form causes extreme swelling and pain in lymph nodes in the neck, groin or armpit, accompanied by headache, fever and delirium (INT -2, THAC0 -4).  DM rolls 1d10 for disease progress:

  • 1-2       Advance to pneumonic form   
  • 3-9        One save vs. death per day until dead
  • 0            Recovery after 3d6 days of symptoms
Pneumonic form causes symptoms as above, along with coughing, sneezing, nausea and vomiting. Character is allowed one save vs. death per day until dead. In the much rarer septicemic form, death occurs automatically within 1d6 hours of onset.

The Bloody Flux.  Generally contracted from dodgy food or drink. Onset after 1d6 days. Acute form results in watery, bloody stools, cramps, fever, and weakness (STR -6, DEX -4, CON -4, THAC0 +4, HP reduced by half). Chronic form results in intermittent diarrhoea and mild abdominal pain (STR -3, THAC0 +1). Despite the name, it is a less serious affliction than the Flux (below), and is so rarely fatal that for game purposes no save vs. death is required, although it can be quite persistent if left untreated.

The Flux. Onset in 1d6-1 (0=1/2) days following contact with infected swamp water, offal, or dung. Profuse, watery diarrhea of a fishy odour and vomiting of clear fluid results in dehydration; use the Starvation and Dehydration chart with first day of symptoms equivalent to first day without liquid refreshment. If untreated, recovery is possible in 1d12 days following onset if a character is lucky enough to survive every save vs. death.

Gonorrhea.  Sexual transmitted infection of the genital tract. Onset after 2d4 days. In males, results in burning sensation in urination and profuse discharge of pus, but may be asymptomatic in females. If infection spreads, fever, abdominal pain and hot, swollen, painful joints (DEX -4, THAC0 +3). Symptoms last 1d8 weeks but sufferers may remain infectious for several months. Serious infection may cause permanent infertility.

Influenza.  Spread by contact with infected person. Onset in 1d2 days. Headache, muscular aches, general malaise, weakness, eye pain, and mental confusion (STR -3, INT -2, DEX -3, THAC0 +2) last for 1d4+1 days, after which respiratory symptoms become more prominent (dry or sore throat, cough, runny nose) with no penalties to ability scores. 

Ipydyme. Similar symptoms to Influenza above, plus diarrhoea; very contagious (each character exposed to infected person must roll 1d20 against CON each day to determine whether they become infected). Initial save vs. death determines direction of disease: on a successful save, the character is infectious for 3d6 days but symptoms are not serious enough to affect ability scores; on a failed save, the character’s discomfort causes a cumulative one point THAC0 penalty each day for 1d6 days, followed by a 2d6 day period of recovery in which THAC0 is regained at one point per day.

The King's Evil. Infection is usually spread through close contact with afflicted persons. The most obvious sign of the disease is a painless, discoloured and inflamed mass in the neck which grows with time and may rupture and become further infected (cumulative -2 CHA per month of infection). Approximately half of cases are accompanied by symptoms of fever, chills, malaise, and weight loss (STR-5, THAC0+3). Symptoms will persist until treated, but disease is not life-threatening. The physical touch of the sovereign of England or France has a 1d6 chance of curing the illness; alternatively, certain rare and very skilled herbalists have been known to have cured it.

Leprosy. Transmitted through contact with the breath of an infected person. After a variable but possibly years-long period of latency, facial features begin to coarsen and the voice becomes hoarse (CHA -2). As the disease progresses, skin eruptions and red nodules are visible, with spots of skin insensitive to cold, touch, and pain (CHA reduced by half, THAC0 +2). In later stages, secondary infections become gangrenous, hands and feet lose feeling, muscle weakness and paralysis set in, and the nose decays (CHA effectively nil as individual is ostracized by society, THAC0 and HP reduced by half, STR and DEX reduced by half). Blindness may occur. Lepers are required by law to wear a covering cloak and carry a bell to announce their presence.

Red Plague.  Transmitted by contact with infected person. Onset occurs in 12 days. High fever, chills, aches, and severe malaise (STR and INT reduced by half, THAC0 +4) persist for 4 days, accompanied thereafter by itchy red lesions on face, arms, legs, and sometimes trunk  (STR, INT, DEX and CHA reduced by half, THAC0 +5). DM secretly rolls character’s save vs. death once during this period to check for mortality by secondary infection). In the absence of secondary infection, lesions break and begin to dry up after 9 days.

The Styche. Sharp chest pain when breathing, shortness of breath, painful swelling of throat and joints (CON -3, THAC0 +5, combat fatigue begins immediately on entering combat). For duration of illness, save vs. poison after 2d6 days; recovery if save successful; if unsuccessful, symptoms persist for another 2d6 days, after which save is made again, ad infinitum.

Typhoid Fever.  Generally occurs during times of prolonged warfare or life in crowded conditions. DM secretly rolls players’ saves vs. poison to determine infection in these conditions. Onset random. Diarrhoea, abdominal pain, high fever, blinding headache, cough, exhaustion and patches of red on the abdomen (INT and WIS -3, THAC0, HP and movement rates reduced by half) persist for 3d10 days. Death occurs on failed save vs. death made once during infection.

Other problems likely to affect characters enduring the elements or spending too long in damp or wet clothing or armour are parasites and fungal infections which may result in varying penalties to AC as the itching distracts the character from full combat prowess, and anal fistula, a nasty affliction following abscesses in the colon which particularly affects men who have spent too long riding in wet saddles, and which reduce a character’s THAC0 and HP by half until treated by a qualified surgeon (THAC0 is then restored immediately, and HP regained slowly in the normal way).

Up till now the party has had a habit of ignoring weather conditions on the assumption that no measurable detriment will come of traipsing around in the pouring rain. I should hope that this last bit should at least make them think twice about doing.


  1. Glad we'll have a paladin in the group.

    1. Oh, aye, she'll be safe on that front all right. But she still has to watch out when swimming in strange waters and protracted adventures without bathing or changing clothes, or she could find herself quite itchy in her holy place.

  2. anal fistula... looking at all these illnesses it feels like a miracle anybody ever survived the middle ages