In Sickness and In Health

Diseases are one of the things that tend to be ignored in fantasy world-building.

That’s not really all that surprising, of course. Most aspects of fantasy tend to focus on the role of sapient beings – be they deities, dragons, or even human(oid)s – because that speaks most closely to potential players. People, be they players or GMs, want to think about the impact that their character(s) will have on the game world, and so new worlds are built around what big men have done, rather than focusing on environmental determinism (of which the impact of diseases on the trajectory of societies is an aspect).

Even when raised, this is typically hand-waved away under the idea that the presence of magic (which most fantasy worlds tend to have) would make diseases a non-issue. Why would villages succumb to a plague when clerics can just prepare remove disease and have that be that? On its face, that does seem to be a good explanation. But in fact, it depends on the game rules in question (for example, the Pathfinder version of the remove disease spell linked previously is notably less effective than the 3.5 version of the spell). Even then, things aren’t nearly as cut-and-dried as they might otherwise be.

For those who have it, page 20 of Pathfinder #8 – Seven Days to the Grave has an interesting sidebar that touches on this for D&D 3.5. Titled “Where Are All the Healers?” it breaks down what the game rules say about city demographics and what they say about resources that can be brought to bear during an epidemic. The end result is that, in the event of a large-scale outbreak, magical healing resources will be too few to effectively combat a widespread disease. (Note that you won’t find this sidebar in the Curse of the Crimson Throne reprint of this particular Adventure Path.)

In the case of diseases, their large-scale impact on history is attributable to different peoples having evolved different degrees of resistance/immunity to particular illnesses. While things like the consequences of the Black Death are easy to take note of, other aspects of diseases on the course of history are subtler. Specifically, they played a major role in large-scale migrations, either abetting them or inhibiting them depending on the varying levels of immunity possessed by native peoples and immigrants. Just look at what happened when Europeans traveled to the Americas for a large-scale example of this. Less notable, but no less important, are instances where immigrating people were depleted or wiped out by diseases that native populations had already grown accustomed to.

So what would all of this look like if we tried to hard-code it into an RPG, such as the d20 System?

Unfortunately, that’s not very easy to do. The game rules treat characters’ ability to resist diseases as a function of a single statistic: their Fortitude save. This number is universal, not taking into account issues of an individual’s genetic ancestry giving them high resistance to some diseases and severe vulnerability to others. Rather than trying to modify the system to represent a more nuanced approach to this, we’ll simplify what we’re trying to portray.

Disease Vulnerabilities by Race

The following table (with most of its racial disease vulnerabilities randomly determined) represents a cross-indexing of the seven standard races with the eleven diseases presented in the Core Rules. Where a given intersection has “–” listed, the standard rules are used should a character of that race encounter that particular disease. In this way, the standard listings for each disease presume that someone fighting it off has an evolved resistance to it via their genetic ancestry.

In this case, the idea of “human diversity and adaptability” is played up; humans enjoy no particular vulnerabilities to any disease, having encountered all of them numerous times over in their spread across the game world. Other races, however, aren’t quite so fortunate. Each of the remaining races has some illnesses to which they’re not very resistant, due to their people only encountering them in relatively recent times. This means that those diseases are more virulent for them, and so pose a greater threat.

Disease Humans Elves Half-elves Dwarves Halflings Gnomes Half-orcs
Blinding Sickness A B
Bubonic Plague B C
Cackle Fever B A
Demon Fever A, C
Devil Chills A, B, C B A
Filth Fever B, C C
Leprosy A A, C
Mindfire B B, C
Red Ache C B B
Shakes B, C C
Slimy Doom A, C A C

Key: A = Increase DC by +4; B = Increase damage by +1 per die (e.g. filth fever now deals 1d3+1 Dex damage and 1d3+1 Con damage); C = Increase necessary number of saves to cure by +1.

The above table works not only as a simplified way of adding a new wrinkle to the presence of diseases in your game, but also contains intriguing suggestions as to what the above connotes about various races in the game world. Notice how half-elves seem to have acquired many of their human half’s resistance to diseases that are otherwise devastating to elves? By that logic, do half-orcs having so many disease vulnerabilities mean that orcs have even worse diseases ravaging them (and that’s why they’ve been pushed back in the face of human and demi-human expansion)? And why do gnomes and halflings have similar levels of vulnerability to certain diseases and not others?

Try making your own such table, and see if a focus on diseases spurs a healthy new interest in designing your campaign world!


7 Responses to “In Sickness and In Health”

  1. krackothunder Says:

    One reason I can think of that plays a part in why diseases aren’t featured heavily is the fact that you can’t really “fight” them. In the game, Evil is often personified and the thing that does harm is a conscious, mortal entity you can punch in the face. Diseases don’t really fit that category: You can mostly just pray for them to go away and hope to somehow prolong your life for a bit before the inevitable happens. Instead of adding such a hopeless and depressing facet of life to the game, it probably made more sense to just include it for the sake of realism and dismiss it just as quickly.

    Of course, same goes for deities, but I considered their inclusion in the d20 games that have them to be a misstep anyway.

    • alzrius Says:

      You’re not wrong that, in games that focus on what particular characters can accomplish (which is usually quite a bit), diseases make for poor “enemies” (though I did once see a monster book where one of the creatures was a six foot-tall germ). But that’s part of the trade-off between simulationism and “game-ism”; by making diseases be handled by a one-size-fits-all Fortitude save, you eliminate the in-game effects of how particular diseases can vary wildly for disparate groups of people who are otherwise the same. I’m of the opinion that a little more leeway can be given to the simulationism side of things, hence this article.

  2. Thoth Says:

    Well, that would definitely have an impact on the demographics and provide some underlying structure to the population distributions.

    I must admit that I rarely use any “diseases” of the “harmful microorganism” sense in d20. Most d20 diseases are utterly generic, and I have a hard time envisioning the microorganism that can infect Humans, Elementals, Living Runes, Quantums, Byakhee, and even Lantern Archons and other “living” spirits that lack physical bodies entirely, but which can’t infect plants (or, for that matter, plain rocks as opposed to an elemental). Worse, if there are diseases that adaptable… between the intercontinental, interstellar, and interdimensional travelers, malign entities, and ways to create new diseases, it’s hard to see why the plagues would stop before most species went extinct.

    If the diseases are more realistically limited to a affecting a fairly small group of species, then realistic epidemiology, biology, and evolution comes into play – which is where your handy chart comes in. I think it will work best in relatively small, closed, settings though, simply because the chart will expand exponentially as additional species and diseases are added.

    Secondarily, of course, realistic diseases just aren’t much fun. Mass graves, crippled, dying, and deceased children, and all the other wreckage and grief a plague leaves behind (as opposed to d20 diseases that mostly leave little or no lingering damage), tend to put a damper on the heroic fantasy. Thus my inclusion of things like “Relieve Illness” on the Hedge Magic spell list, Witchcraft Healing and Immunities in Eclipse (and the “Peasant Powers” package), the Sweat Stone Charm in The Practical Enchanter, rituals like the “Blessing of the Innocents” (Orin) or Legend’s Of High Fantasy’s Tears Of Heaven, the option of using Eclipse’s Battle Magic modifier on curative spells, the Ring of Aesculapius in the Industrial Wrights And Magic articles, and the general disease resistances of the Atheria and Star Wars campaigns.

    I do use plagues – but they just tend to be manifestations of curses, or areas of tainted magic, or the work of malevolent entities, or spiritual illnesses that feed on life force, or just seriously weird (Everywhere I go the mice start lighting fires!). They’re best dealt with by attempting to contain the damage while some adventurers go after the source – in the most abstract cases by using powers like Eclipse Witchcraft’s “Master The Elements” ability which explicitly allows the user to personify and confront abstract or normally impersonal problems like plagues.

    A lot depends on the scale of the setting too. In a younger setting – perhaps the colonization of an unknown continent, the spread of one or more successor species over a world where the elder races wiped themselves out, or a world that was only recently created – terrible plagues which the races must learn to avoid, find a way to cure, or simply adapt to, to survive, horribly menacing creatures and deadly discoveries, and the accidental unleashing of true global menaces, is a lot more credible than it is in a sprawling, multiversal, eons-old, setting. After all, if galactic civilization has been around for three billion years, then very little is going to be truly new – so a bit of plague, or a hostile civilization starting a war, or some newly rediscovered bit of technology, that seems to threaten the galaxy is almost certainly quickly going to run into various limiting factors. Otherwise galactic civilization would never have gotten to be three billion years old in the first place.

    And another comment almost long enough to turn into an article. Well, I shall see if I think of anything else.

    • alzrius Says:

      Thanks for the substantive comment! I’m glad that the article warranted such a lengthy response.

      Unfortunately, you’re right that diseases whose viability is limited via evolved resistances (or lack thereof) among populations doesn’t really mesh with the underlying presumptions of the d20 System. I ran into that when outlining this article, since I quickly realized that even just limiting the above table to creatures of the Humanoid type would have made it ridiculously unwieldy. And even then, as you noted, most d20 diseases are presented as being universal in the sort of living creatures they can potentially infect anyway.

      Ultimately, that’s a consequence of the d20 System’s disregard for simulationism, at least as compared to more gamist design. Of course, most RPGs have to strike a balance between those two poles anyway. I just wanted to try and move things a little further toward the simulationist side, and maybe help provoke some thought with regard to an oft-overlooked aspect of game-world design.

      • Thoth Says:

        Well, individual characters may come and go, but setting design goes on forever – and, given that I lean heavily towards simulationism myself, any article on “tweaking the rules for realism” is always welcome.

        I think the generic nature of d20 diseases is also a consequence of the usual playstyle and settings. When the party may consist of a lizard-creature, a robot/golem, an undead, a demon/dwarf hybrid, and a human, it would be entirely reasonable to have a disease that only affected one of those characters. But if you bring it into play, it’s going to be hard to avoid the perception that you’re picking on whatever character it is that it affects – and you might have random die rolls leaving one player pretty much out of the game for the night if the group doesn’t have a convenient cure (and if they do, treating only one character is trivial). On the social side, a plague that only really affects a particular subgroup of the general population just isn’t as terrifying – and is much easier to isolate and treat.

        Now, I have seen people arguing for medieval-setting ignorance – “No one knows what causes disease!” – but honestly… that implies that no one ever brought that knowledge back from another plane, that no one has ever had a really high knowledge skill in the appropriate field, and that no one has ever spent 500 GP on Commune – “What causes this plague?” “Germs”. “What are Germs?” “Tiny living things”…. and it doesn’t matter where it goes from there. The clues have been given. (And if it’s not germs, the same mechanisms will still reveal whatever-it-is).

        That does give me an idea for a Negative Energy Spell though!

        Entropic Burst

        School: Necromancy (Death), Level: Bard 2, (Neutral or Evil) Cleric 2, Sor/Wiz 2.

        Casting Time: 1 Standard Action, Components: V, S, MF (A sharp flake of Obsidian), Range: Zero, Target: Special, Duration: Instantaneous. Saving Throw: None, Spell Resistance: No.

        Entropic Burst creates a ripple of negative energy in fabric of the universe. All independently living creatures within a 30′ radius of the caster, not excluding the caster, will suffer 1 point of divine damage, regardless of intervening barriers other than Negative Energy Protection. This includes creatures on the other side of walls, internal parasites, non-symbiotic bacteria, burrowing creatures, and skin fungus, as well as the vast majority of creatures other than plants, constructs, undead, and other creatures that are not technically alive. This will, among other effects, instantly halt the progress of a broad variety of diseases, but does nothing to help repair any damage which is already done.

        Hm. Another reply or two and we will have enough here for more articles.

      • alzrius Says:

        I meant to reply to this a few days ago, but somehow wasn’t able to find the time.

        I have to admit, that spell seems like a good way to perform pest control, or perhaps engage in magical chemotherapy. That said, I’m not quite sure what it means by “halt the progress” of a broad variety of diseases. Are the diseases wiped out (because that would make this spell function like remove disease, which is a higher-level spell, or does it simply suppress them for a certain period of time (e.g. a day)?

  3. Thoth Says:

    It depends on the disease mechanism; For example, a spiritual corruption, a dark curse, contamination by tainted magic, or a negative-energy infection that feeds on your life energy could all be “diseases” as d20 defines them – but they aren’t independent living things, so this spell won’t affect them. It wouldn’t work on a viral or prion infection either; those are not independently living things .

    Now it WOULD neatly eliminate the infectious organisms involved in Amoebic or Bacterial Dysentery, or Clostridium Botulinum, or some forms of Pneumonia – but it will do nothing to repair the damage to the victim(s) colons,to remove the toxins already present in their system, or to clear their lungs – and those problems could still easily kill.

    For a practical benefit, for any diseases where it will actually eliminate the infections organism, I’d give a cumulative +2 modifier on each successive fortitude check. That way anyone who wasn’t too badly off will almost certainly be fine, but anyone who was already in really bad shape may still die.

    Although the chance of most game masters going into that much detail on how diseases work is probably fairly slim anyway. It just struck me as an interesting idea.

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