Very few games have disease at their core, but many have tiny subsystems for dealing with disease in various ways. If a game has such mechanics, they tend to be "third-tier", one-off systems. I've yet to see any that were any good. (Most usually imply that no one ever gets sick or that everyone dies from the least infection.)

Can anyone recommend a game that has a reasonable system for dealing with disease? I don't have a particular goal here, but rather am more interested in what moving parts make a disease system work towards whatever goal it is intended.

As an example, many systems assign "traits" of some kind to diseases, but what these traits are often seem totally wrong. What traits does a working disease system have (for some loosely arbitrary definition of "working")?

As an ancillary question: in what conditions have you seen disease even be interesting in a game?

I'd have to agree, most games lump diseases in with poisons at the back of the combat section (using them as a non-combative way to suffer damage and unusual penalties), or they might include diseases as a part of the monster glossary.

I've just checked my shelf through a couple of dozen game systems, and haven't seen any that reminded me of a decent simulation mechanism for disease.

But I've been thinking about a very similar topic for a while, so I can tell you what I'd like to see...

1) A decent list of at least twenty diseases. Each of which has basic symptoms, advanced symptoms, a disease course, an end game and a remedy.
2) The basic symptoms come from a list of ten or so key terms (high-fever, coughing, blurred vision, high blood pressure, etc.). The players aren't told what disease they have, only the symptoms they are suffering. Advanced symptoms could come in at the final stages of the disease, or they could be detected before they manifest if the character is subjected to a successful medical check.
3) As the disease continues its course, there would be a count-down before advanced symptoms kick in. Certain failed treatments might accelerate this course, certain remedies may simply slow down the course of the disease without actually curing it.
4) Once the disease course has reached a heightened stage where the advanced symptoms manifest, it becomes more difficult to cure, but the exact nature of the disease becomes known. This is make or break time and it's either a case of cure the disease or let it run its end game.
5) If the disease is cured, it's symptoms are gradually removed from the character as the drugs/healing/therapy neutralise the effects the disease has had so far. If the disease is not cured, the end game comes into effect. This could be death, permanent impairment, in the case of a common cold it could simply go away (or could set up for a new and more dangerous version of the disease to take it's place if the immune system is compromised...Influenza).

That's how I've been thinking of doing it.

Just some ideas...

V

It could use some work, but I kind of like how 4E D&D handles disease and poison.
Generally, diseases have three stages, each with different effects.
Each turn, you roll your save.
Each time you fail a save, the disease progresses to the next stage.
Each time you succeed a save, the disease goes back to a previous stage.
If you succeed a check against the first stage of the disease, the disease is overcome.

Many of the monsters in the Monster Manual feature their own unique poisons and diseases with different effects. It is very easy to customize these as all you have to do is mix and match different effects throughout the stages.
For example, I created this one disease called Tucker's Fever. In the first stage, it deals heat damage. In the second stage, it deals more heat damage and the afflicted person is dazed. In the final stage, the afflicted person takes huge heat damage and collapses, falling prone.

My biggest problem though is how easy it is to get rid of diseases. Theres one ritual that cures every disease! I tried to houserule it out so I could use Tucker's Fever as an adventure hook to try and get the players to go on a quest for a special healing herb, but the players rebelled against me and demanded to have that ritual back. Argh.

I think part of the problem is that there's such a vast variety of diseases, you'd need a catalogue to be realistic. However, that would end up putting too much focus on a thing which really does come up rarely. (We all get colds and the occasional flu, but is it worth it simulating this in a game? The rarer diseases are just that.. much rarer.) On top of that, there's the simple "Cure Disease" spell in D&D.

Not that I'm disagreeing.. would be nice to have diseases in a game.

Dan

Hello Wordman,

Treat diseases as a character progressing through an adventure.
If in Dnd20

They level up, gain hit points and feats(symptoms), and increase draining capacity.
Some my "Cross-Class"

Diseases have 1 hit point per lv plus what they drain

example
Day 1  lv1 disease attacks character (rolls d20 plus lv[1]  vs fort save)
         Disease is successful it drains 1d4 hit points[2], disease also levels up and gains a feat.
         GM chooses nerve disorder feat.[reduces a characters roll by 1d4 on any dex or int skill check.]

Day 2  lv2 disease attacks character ( rolls d20 plus lv[2] vs fort save)
         Disease fails disease takes damage equal to constitution mod of character[2].
         Disease is still alive so the GM may still use the nerve disorder feat

This could go on for how ever long the GM wishes

Diseases are really only interesting in two situations (similar to freezing to death, dying from dehydration or starvation, etc):
1) The game is simulationistic; if someone catches the plague (or whatever), everyone expects the system to describe what happens in a somewhat realistic manner.
2) In a narrativistic (or whatever) game, you use it as a plot point: A PC (or NPC, or town, whatever) suffers from a rare disease, and the plot of the scenario basically revolves around finding a cure.

In both of these situations, I think a good system for handling diseases could be helpful. In (1), it's just an integral part of the game: Stuff that happens should have logical consequences. In (2), if you have a fairly uncaring system, it increases tension. If the players know that the GM won't kill their PCs just because they have the plague (because they're heroes, right?), the disease itself won't feel important. If the players know that the GM has no control over what the disease does to them, the bog-standard "Find the McGuffin" scenario becomes a race against time, which could be fairly exciting.

The DnD4 system chronoplasm mentions seems like a good starting point, but it seems like it could be fairly unbalanced in that certain characters (with high values in the relevant ability scores) becomes immune do disease while other characters (with low stats) can't even recover from a cold. I haven't checked out the system myself, so I wouldn't know for sure, but that's just what it seems like to me.
Come to think of it, you could handle other disease-like conditions (disease-like from a dramaturgical viewpoint, at least) like freezing to death, starvation, etc, just like diseases under the DnD4 system, just that the roll's difficulty increases the longer you go without food, water or whatever. I mean, it serves the same dramaturgical purpose, so why not lump it under one system?

I'm sorta-kinda working on a technothriller game with a heavy emphasis on bioterrorism.  As you might expect, the rules for diseases and medical treatment in general are pretty deep.  PM me if you want to see the chapter.

-G.

walruz wrote:
The DnD4 system chronoplasm mentions seems like a good starting point, but it seems like it could be fairly unbalanced in that certain characters (with high values in the relevant ability scores) becomes immune do disease while other characters (with low stats) can't even recover from a cold. I haven't checked out the system myself, so I wouldn't know for sure, but that's just what it seems like to me.

chronoplasm wrote:

walruz wrote:
The DnD4 system chronoplasm mentions seems like a good starting point, but it seems like it could be fairly unbalanced in that certain characters (with high values in the relevant ability scores) becomes immune do disease while other characters (with low stats) can't even recover from a cold. I haven't checked out the system myself, so I wouldn't know for sure, but that's just what it seems like to me.

It has its issues. Character advancement does result in power creep. If you want to challenge the character with high fortitude, you have to constantly throw deadlier and deadlier diseases at them. The problem is that a disease that may be slightly challenging to the dwarf may be lethal to the hobbit. It's a typical problem; how do you challenge the specialist without making the problem impossible for the rest of the party?

One nice thing though; even without the ritual of cure diseases, other party members can perform heal checks to help the afflicted person overcome their disease.

In RuneQuest (the Games Workshop edition) diseases are categorised by which attribute they effect. If I remember correctly, the virulence of the disease is represented by the attribute multiplier (for a 3-18 attribute) used to determine your percentage chance of resisting further progress. If you fail a roll, you lose 1 point of that attribute. If an attribute reaches 0 you die. The attribute loss is permanent, which makes disease bloody scary. The frequency of recovery rolls varies by disease and allows you to tailor how the disease progresses. There is also a 'treat disease skill'. A must-have for any serious healer.

I don't think you don't need a list of diseases, just a general way of categorising them. Disease can be varied further by giving them different, hideous symptoms - from a sore throat to pus from every orifice. Nice.

Bert

"The art of medicine consists of amusing the patient while nature cures the disease.”
Voltaire

In BTRCs older products, Spacetime I beleive, there was a disease, poison and drug system laid out. The format for each were similar; delivery mechanism, onset time, effects associated with each stage, stage length. The effects themselves, like convulsions or paralysis, were written up separately, with their own details about effects on stats and skills.

That was about as detailed as I could ever ask. Note however, I am a fan of Greg Porters work in game design, so the system is probably more detailed than many would care to use. Regardless I find it to be a good reference.