Alternate Disease Rules for GURPS

Disease

I originally wrote these rules for 3rd edition GURPS and sort of ignored them after 4th edition came out. But I guess I never really cared for how diseases were handled in 4th edition, it just didn’t feel “scary” the way real world diseases are. So here is my rewritten for 4th edition version of my disease rules. I also use d3’s for some things and don’t really violate the d6’s only ethos of GURPS…

These rules are an attempt to make GURPS diseases into the subtle and frightening killers that real-life diseases can be.  In game terms this means drawing out the effects of the disease and making the player unsure of exactly what is wrong with him.  Each of the diseases detailed here follow the same format, the details of which are described below.  At the end of the list of maladies is an in depth treatment of various symptoms that accompany many ailments.  The effects of many of these symptoms will be just as dangerous as the disease which causes them.   All of the diseases that are described below are from reality, except Corpse Fever which is from Domibia.  Also it should be mentioned that I have intentionally given treatments that are appropriate for a low tech or fantasy setting.  At some point I might add the modifiers for modern drugs and treatment.
    Note:  Fatigue loss listed in the text is usually meant to remain until the disease has passed. Any HT rolls made while diseased should use HT-(1 for every full 20% of Fatigue currently missing, shorthanded as just “Fatigue mod”). Alternately, you can use Douglas Cole’s awesome “The Last Gasp” from Pyramid 3/44.

               Virulence: To avoid infection an exposed character must roll a Resistance Roll using HT (- any Fatigue mod) versus the Virulence of the disease. The advantage Disease-Resistant gives the character +8 HT on this roll. For continuous exposure (like living in a place with plague-bearing fleas) a roll should probably be made every day.

            Symptoms: The symptoms that accompany the disease are listed here, sometimes differing by what stage the disease is in. The details of the various symptoms are given game descriptions after the lists of diseases. Symptoms that use standard GURPS Conditions will be underlined in the text. Any symptom in italics has no game mechanics. Some symptoms are only seen during the second stage of the disease and are marked with an *asterisk. Some symptoms don’t always appear, make a 3d roll to see if that symptom is present (eg: 7+ means that that symptom is present on a roll of 7 or higher).

                Incubation: All diseases have an incubation period, during which they are undetected. After the incubation period ends, the disease begins the 1^st Stage. Once the 1^st Stage has run its course the 2^nd Stage will begin, after which recovery is possible if still living.

                Diagnosis: A diagnosis skill roll may not be attempted until the 1^st Stage of the disease has begun. All diseases have two modifiers to the Diagnosis skill, one for the 1^st Stage and one for the 2^nd. A failed roll will result in a misdiagnosis, the effects of which vary from disease to disease and are listed in the description of each disease.

                Treatment: Treatments for each of the diseases are listed in the descriptions. Treatment that is begun during the 2^nd Stage of a disease will not be as effective, multiply any modifiers by 75% and round down.

                Recovery: If a character receives proper treatment for a disease, they may attempt a Recovery roll after each Stage of the disease has passed. If a character does not receive proper treatment a Recovery roll may only be attempted when the 2^nd Stage has run its course. Recovery is a quick contest of (HT + Physician skill of person giving aid + Treatment modifiers) versus the Recovery number of the disease (highest margin of success wins). There is a chance of dying if the Recovery roll fails after the 2^nd Stage, the roll to avoid death is listed in the description of each disease.

            Roll to Avoid Death: If the character fails the second Recovery roll they must roll to see if they die. This has nothing to do with remaining HP’s, they simply die from the disease or complications caused by the disease. The roll is unmodified, except for any Fatigue modifiers.

            Post Recovery: If death is avoided then the character begins the Post Recovery Stage. The Post Recovery Stage has two values, one for use with characters who received no medical treatment and one for those that did. The effects of the Post Recovery Stage are given in Fatigue points, which will last for a certain number of days. Usually the Fatigue will heal over the course of the Post Recovery Stage, rather than having it all suddenly go away at the end of the period (so with dysentery, you would recover one FP every 2 days if you received no treatment, with the final FP healing on day 7). Every 2 points that you succeed or fail the Recovery roll by modifies the Post-Recovery Stage by an amount shown (eg: a Post Recovery Stage of 10 weeks (+/- weeks) would actually be 11 weeks if you failed the Recovery roll by 1 or 2 points).

Examples of some common diseases

 

Bubonic Plague	Course of Disease
Transmission; Rat-borne fleas	Incubation Period; 1d days
Virulence; 6	1st Stage; 5 days
Symptoms; Fever, swollen lymph nodes, severe abdominal pain, moderate head pain, *fluid-filled lungs, *coughing	* 2nd Stage; 10 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 21
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT-1
Misdiagnosed as; Minor Disease, Pneumonia	Post Recovery Stage; 10 weeks (+/- weeks)
Treatment; Relieve Pain (+1) & Fever (+2)	With Treatment; 4 FP
	Without Treatment; 4 FP

 

Cholera	Course of Disease
Transmission; Contaminated food and/or water	Incubation Period; 1d-1 days
Virulence; 8	1st Stage; 3 days
Symptoms; Fever, diarrhea, vomiting (7+)	2nd Stage; 3 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 20
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT
Misdiagnosed as; Dysentery	Post Recovery Stage; 3 weeks (+/- 3 days)
Treatment; Relieve Pain (+2) & Fever (+2)	With Treatment; 4 FP
	Without Treatment; 4 FP

 

Dysentery	Course of Disease
Transmission; Contaminated food and/or water	Incubation Period; 1d3+1 days
Virulence; 11	1st Stage; 3 days
Symptoms; Abdominal pain, diarrhea	2nd Stage; 7 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 17
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT+3
Misdiagnosed as; Cholera, Minor Disease	Post Recovery Stage; 5 days (+/- days)
Treatment; Replace Fluids (+5), Relieve Pain (+3)	With Treatment; 2 FP
	Without Treatment; 4 FP

Food Poisoning	Course of Disease
Transmission; Contaminated food	Incubation Period; 1 day
Virulence; 6	1st Stage; 2 days
Symptoms; Severe abdominal pain, abdominal cramps, diarrhea (10+), fever (11+), vomiting	2nd Stage; 7 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 14
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT+6
Misdiagnosed as; Cholera	Post Recovery Stage; 1 week (+/- days)
Treatment; Relieve Symptoms (+4)	With Treatment; 2 FP
	Without Treatment; 4 FP

Influenza	Course of Disease
Transmission; Contact with infected person, airborne particulates	Incubation Period; 1d3 days
Virulence; 10	1st Stage; 1d days
Symptoms; Cough, fever, *fluid filled lungs (14+), head pain, malaise, stuffy nose	*2nd Stage; 1d+1 days
Diagnosis; 1st Stage; Diagnosis -2	Recovery; 15
Diagnosis; 2nd Stage; Diagnosis	Roll to Avoid Death; HT+5
Misdiagnosed as; Minor disease, smallpox	Post Recovery Stage; 4 days (+/-days)
Treatment; Relieve Pain (+1) & Fever (+1)	With Treatment; 2 FP
	Without Treatment; 4 FP

Minor Disease	Course of Disease
Transmission; Varies	Incubation Period; 1d3 days
Virulence; 1d+2	1st Stage; 1d days
Symptoms; Fever, general body pain, vomiting, discoloration (12+ for each), discomfort	2nd Stage; 2d days
Diagnosis; 1st Stage; Diagnosis +(1d-3)	Recovery; 10
Diagnosis; 2nd Stage; as above + 2	Roll to Avoid Death; No chance of death
Misdiagnosed as; Another Minor Disease	Post Recovery Stage; 1d3 days (+/- days)
Treatment; Relieve Symptoms (+1d3+1)	With Treatment; none
	Without Treatment; 2 FP

Pneumonia	Course of Disease
Transmission; Contact with contaminated person, air-borne particulates	Incubation Period; 1d3+3 days
Virulence; 8	1st Stage; 5 days
Symptoms; Cough, chest pain, fever, fluid-filled lungs, general discomfort	2nd Stage; 9 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 19
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT+1
Misdiagnosed as; Minor Disease, Plague	Post Recovery Stage; 4 days (+/- days)
Treatment; Relieve Pain (+2) & Fever (+2), on a successful Physician roll (+5)	With Treatment; none
	Without Treatment; 2 FP

Pneumonic Plague	Course of Disease
Transmission; Contact with air-borne particulates	Incubation Period; 1d3 days
Virulence; 11	1st Stage; 3 days
Symptoms; Cough, chills, fever, fluid-filled lungs	2nd Stage; 7 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 22
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT-2
Misdiagnosed as; Minor Disease, Pneumonia	Post Recovery Stage; 10 weeks (+/- weeks)
Treatment; Relieve Pain & Fever (+1)	With Treatment; 4 FP
	Without Treatment; 4 FP

Rabies	Course of Disease
Transmission; Contact with body fluids, usually through animal bites	Incubation Period; 1d weeks
Virulence; 6 (immediate washing reduces to 4)	1st Stage; 1d3+1 days
Symptoms; *Excessive sweating, fever, *hyperactivity (10+), malaise, sore throat, *severe joint pain,	*2nd Stage; 1 week
Diagnosis; 1st Stage; Diagnosis	Recovery; 26
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT-6
Misdiagnosed as; Minor Disease	Post Recovery Stage; 15 weeks (+/- weeks)
Treatment; none	With Treatment; 4 FP
	Without Treatment; 4 FP

Smallpox	Course of Disease
Transmission; Contact with infected persons (direct or indirect)	Incubation Period; 2d+5 days
Virulence; 8 (5 if indirect contact, clothing, etc)	1st Stage; 1d3+1 days
Symptoms; Abdominal pain (13+), fever, general pain, head pain, malaise, *rashes (face & limbs)	*2nd Stage; 1d+7 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 18
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT+2
Misdiagnosed as; Influenza	Post Recovery Stage; 2 weeks (+/- days)
Treatment; Relieve Pain (+1) & Fever (+1)	With Treatment; 2 FP
	Without Treatment; 4 FP

Tetanus (Lockjaw)	Course of Disease
Transmission; Bacteria entering through break in skin	Incubation Period; 3d days (1d+2 days if wound is on the head)
Virulence; 8	1st Stage; 3 days
Symptoms; Difficulty swallowing, lockjaw, *muscle spasms, sweating	*2nd Stage; 2d days
Diagnosis; 1st Stage; Diagnosis + 2	Recovery; 17
Diagnosis; 2nd Stage; Diagnosis + 4	Roll to Avoid Death; HT+3
Misdiagnosed as; Dysentery	Post Recovery Stage; 8 weeks (+/- weeks)
Treatment; none	With Treatment; 4 FP
	Without Treatment; 4 FP

Typhoid Fever	Course of Disease
Transmission; Contact with contaminated person, contaminated food and/or water	Incubation Period; 1d3 days
Virulence; 6	1st Stage; 1 week
Symptoms; Apathy, cough, general body pain, severe fever	2nd Stage; 1-2 weeks
Diagnosis; 1st Stage; Diagnosis – 2	Recovery; 17
Diagnosis; 2nd Stage; Diagnosis	Roll to Avoid Death; HT+3
Misdiagnosed as; Pneumonia, Plague	Post Recovery Stage; 3 weeks (+/- weeks)
Treatment; none	With Treatment; 4 FP
	Without Treatment; 4 FP

Typhus	Course of Disease
Transmission; Carried by body lice	Incubation Period; 1 day
Virulence; 6	1st Stage; 5 days
Symptoms; Fever, headache, rash	2nd Stage; 10 days
Diagnosis; 1st Stage; Diagnosis + 2	Recovery; 16
Diagnosis; 2nd Stage; Diagnosis + 4	Roll to Avoid Death; HT+4
Misdiagnosed as; Minor Disease	Post Recovery Stage; 1 week +/- days)
Treatment; none	With Treatment; none
	Without Treatment; 4 FP

Corpse Fever (Domibian)	Course of Disease
Transmission; Bite or claw wound of a M’rrr	Incubation Period; 1d3 days
Virulence; 6 (4 for simple contact)	1st Stage; 3 days
Symptoms; Fever, general body pain, malaise	2nd Stage; 5 days
Diagnosis; 1st Stage; Diagnosis	Recovery; 17
Diagnosis; 2nd Stage; Diagnosis + 2	Roll to Avoid Death; HT+3
Misdiagnosed as; Plague	Post Recovery Stage; 1 week (+/- days)
Treatment; Relieve Pain (+1) & Fever (+2)	With Treatment; 2 FP
	Without Treatment; 4 FP

Symptoms

Apathy

Treat as Drowsy and the Absent Minded disadvantage.

Bleeding

Bleeding; You lose 1d3 HP which remain missing until the disease has passed. This represents a continuous slow loss of blood. Each day make a HT (- Fatigue mod) roll, on a Critical Failure the Bleeding becomes Hemorrhaging.

Hemorrhaging; You lose 2d3 HP which remain missing until the disease has passed, in addition you lose 1d-4 HP per day. You may roll to heal this extra HP point loss normally.

Coughing

You are treated as Coughing and in addition all sleep periods are treated as being only half as long when suffering from a cough. Thus an 8-hour sleep period would only count as 4 hours of sleep for the character, possibly assessing FP.

Diarrhea

Normal Diarrhea; Roll HT (- Fatigue mod) every day, a failed roll results in the loss of 1d-4 HP (in this case representing generic bodily fluids). Each point lost increases the amount of fluid needed to avoid dehydration by 10%. A Critical Failure results in Severe Diarrhea.

Severe Diarrhea; As per normal diarrhea, except the HT roll is at an additional -2 and the HP lost from fluid loss is 1d-3.

Excessive Sweating

Roll HT (- Fatigue mod) every day, a failed roll results in the loss of 1d-4 HP (in this case representing generic bodily fluids). Each point lost increases the amount of fluid needed to avoid dehydration by 10%.

Fever

Normal Fever; Each day the fever causes 1d-4 damage, which may be healed normally. Each day also requires a HT+2 roll to avoid the fever becoming severe.

Severe Fever; Each day of the fever causes 1d-2 damage, which may be healed normally.

Fluid Filled Lungs

Every day causes the loss of 1d-3 HP, representing general fatigue, loss of oxygen, strain on the body and the actual filling of the lungs.

Lesions & Rashes

Lesions; Open sores appear on the character. They start out as 1 point of damage and progress by 1d-4 points per day. These will not heal until the disease has run its course. Each major body location can be afflicted separately (head, torso, legs and arms). Rolls should also be made to avoid infection (B444) as well.

Rashes; Rashes cause 1d-4 damage per effected location each day. Once any damage is caused a roll for infection must be made as with Lesions.

Malaise

Treat as Drowsy and the Absent Minded disadvantage.

Muscle Spasms

Muscle Spasms; Treat as Moderate Joint Pain with occasional spasms that occur every HT minutes (an unmodified HT roll will avoid this). The spasms do 1d actual damage, representing torn muscles and broken bones. The spasms last for 1d3 minutes and the character is treated as being in Agony.

Pain

Abdominal Cramps; A HT-2 roll must be made every 10 minutes (just roll whenever it is necessary to know how bad the cramps are effecting the character), failure results in Moderate Abdominal Pain, and a critical failure results in Severe Abdominal Pain. The attack of cramps lasts for a number of minutes equal to the “pain” that is inflicted, decreasing in intensity by 1 point per minute.

Moderate Abdominal Pain; The character suffers Moderate Pain.

Severe Abdominal Pain; The character suffers Severe Pain and additionally has their Move score lowered by 20%.

Normal Chest Pain; The character suffers Moderate Pain.

Severe Chest Pain; The character suffers Severe Pain.

General Pain; The character suffers Moderate Pain.

Moderate Head Pain; The character suffers Moderate Pain.

Severe Head Pain; The character suffers Severe Pain.

Moderate Joint Pain; The character suffers Moderate Pain and additionally their Move score is reduced by 20%.

Severe Joint Pain; The character suffers Severe Pain and additionally their Move score is reduced by 40%.

Vomiting

Vomiting: Treat as Nauseated.

Chance for Disease to be Present

Encampments
Roll 14+ for disease to be present
3d Type of Disease

3-7 Dysentery
8 Food Poisoning
9 Cholera
10-11 Minor Disease
12 Influenza
13 Smallpox
14 Pneumonia
15 Typhoid
16 Typhus
17 Bubonic Plague
18 Pneumonic Plague

Settlements
Roll 15+ for disease to be present
3d Type of Disease

3-7 Dysentery
8 Food Poisoning
9-11 Minor Disease
12 Cholera
13-14 Influenza
15 Smallpox
16 Pneumonia
17 Typhus
18 Bubonic Plague

Animals
Roll 16+ for disease to be present
3d Type of Disease

3-9 Food Poisoning
10-13 Minor Disease
14 Typhus
15 Rabies
16-18 Bubonic Plague

Contaminated Water
Roll 16+ for disease to be present
3d Type of Disease

3-10 Dysentery
11-12 Typhoid
13-18 Minor Disease

Cuts and Scrapes
Roll 16+ for disease to be present (15+ in rural area)
3d Type of Disease

3-12 Minor Disease *
13-18 Tetanus

*This can just be an infection from a dirty cut. In that case the wound will not heal until the infection runs its course. Just assume the symptoms are General Body Pain & Fever rather than roll randomly).