Modeling and curing real-world diseases in D&D

[Fiery Diamond]

Presume that you were going to include real-world diseases in a D&D game or a novel using D&D rules. (I'm doing the latter, writing a story where some characters function off of D&D rules while living on Earth.) Discuss how you would model them and what spells would be necessary to reverse them.

Two I'm thinking about: Cancer and Alzheimer's. Remove disease (or Heal) would stop things from progressing. The question I'm pondering is what would be necessary to reverse the damage? Would Restoration (or it's Greater variant), removing any physical or mental ability drain be enough? Or would one need Regenerate, to restore the parts of the body or brain that were ruined? I'm leaning toward "you need both Regenerate and Restoration," but I'm having trouble deciding.

What do you all think, and how would you handle the topic in general?

[Vahnavoi]

The whole point of versions of D&D having their own systems for disease is for you to use those to model disease. Which means they are cured by Remove / Cure Disease and any damage they do is either to hitpoints or ability scores, treated by effects that restore hitpoints or ability scores. 1st Edition AD&D had some specific rules for mental disorders too, but I don't remember them from the top of my head.

Anything else is overthinking it.

[Fiery Diamond]

The whole point of versions of D&D having their own systems for disease is for you to use those to model disease. Which means they are cured by Remove / Cure Disease and any damage they do is either to hitpoints or ability scores, treated by effects that restore hitpoints or ability scores. 1st Edition AD&D had some specific rules for mental disorders too, but I don't remember them from the top of my head.

Anything else is overthinking it.

That was my initial thought, actually, but then I got to thinking about the point of Regenerate. I mean, most of the things that Regenerate fixes don't actually have game rules for causing. For example, it grows back lost digits and limbs. There isn't any way to lose digits or limbs outside of DM fiat, unless you're a hydra. It fixes broken bones. No way to break bones, either. Perhaps even more significantly for the case of modeling real-world diseases, "ruined organs grow back." The other benefits of Regenerate (healing damage and nonlethal damage, removing fatigue and exhaustion) are extremely underwhelming for a level 7/9 spell.

So what is the point of Regenerate as a high-level spell, if all the things it fixes can't actually exist outside of fiat? And, if we're relying on fiat, when should fiat be used in the first place? Especially the "ruined organs" bit, which for some reason I'm stuck on.

But your answer to the initial question is certainly a valid one. And, well, when in doubt, go for the simplest answer is also a valid approach.

Tangent related to the topic: would giving Regenerate the "cure ability damage and drain" parts of Greater Restoration as a mechanical effect of "ruined organs grow back" be unbalanced? Regenerate doesn't have an expensive material component, while Greater Restoration costs 5000GP, but most of the cost is associated with removing negative levels. Maybe if you gave Regenerate a component cost of something like 500GP? (Restoration costs only 100GP when not fixing a negative level, and it fixes drain from one ability score, so that seems roughly in line.)

[Satinavian]

D&D makes mechanical distinction between deseases and age problem. But in the real world people never die of age alone.
It is always deseases, mostly because we everything that can go wrong in a body a disease. Even if it is basically just wear and tear or complications arising from that.


So i don't think every realworld "disease" is meant to be a mechanical disease. Some are mechanical age category modifiers, some are maximum age.


And it is on you to decide which is which when you apply the rules. Diseases can be cured "cure disease" and similar tools, for age related stuff, well there is an abundace of options for that that explicitely say so but are mostly harder to come by than a single casting of a level 7 spell.

And yes, regenerate is underwhelming in as only being really useful as plot device/ via fiat. But the spelll exists because there was a need for it. Losing limbs did happen and still does happen, even if it is handwavy.



I mean, D&D has supernatural diseases like mummy rot that have special rules for curing. But i don't thing modelling mundane real life diseases should get similar special treatment.

[Martin Greywolf]

What is your goal here? For most groups, Cure disease fixing everything is just fine, because they are playing a tactical fighting game and don't want to suddenly switch to grand strategy epidemiology simulator.

If you want anything more nuanced, DnD is bad at that. As are almost all TTRPGs. That's not really a criticism of them, they are meant to be a workable approximation of something specific (usually combat), and when you go outside of that, things start to fall apart. With a topic as outside of that context as this, you're better off taking the dice, look at what probability distributions you can get from them and build something from scratch. It's gonna be a whole lot less painful than trying to bend a system not meant for that out of shape.

[Fiery Diamond]

And yes, regenerate is underwhelming in as only being really useful as plot device/ via fiat. But the spelll exists because there was a need for it. Losing limbs did happen and still does happen, even if it is handwavy.

As factual as this may be, it really rubs me the wrong way, for two reasons: I, personally, have never been in a game where "it does happen," and if a DM tried to make it happen to a PC rather than an NPC, I would cry foul; and the very idea of a "plot device spell" that takes actual resources from a player just runs counter to how I think of the game.


What is your goal here?

Truthfully? There are two. The initial one is pretty straightforward and very niche: I want to explore and extrapolate on what would happen if someone with access to D&D magic tried to use that magic to fix real-world problems. If someone had "remove blindness/deafness," they could give sight to blind people and hearing to deaf people. If someone had regenerate, they could regrow amputated limbs or negate the need for organ transplants. if someone had remove disease they could cure real-world diseases. And so on.

The second was born of my contemplations on the first: if fixing the damage to organs and such from diseases can be done with restoration spells, where does Regenerate fit in? In the "D&D magic in the real world," the answer seems to be just regrowing limbs unless fixing organs also fixes the same problems that Restoration does. In an actual game, I despise the whole "plot device spell to fix fiat problems" concept, hence my mechanical change suggestion to Regenerate, which keeps it relevant on the game mechanics level. The for that is finding a way to make the high-level resource actually do something that fits with its "fluff."

[Phhase]

I actually wouldn't mind some guidance on this topic too, albeit slightly less grounded in reality. In my setting (5e, for reference), there was a war in recent history where an empire of evil humans from the north used horrifying magical disease bioweapons as war tactics against the rest of the continent. There were four diseases:

The Plague of Beasts - A waterborne disease that acts pretty much like Bloodborne's Beast Plague, turning one into a dangerous, feral, infectious monster.
The Plague of Vermin - A plague that slowly caused organic materials to transform into vermin like locusts or rats, which then chewed their way out to wreak havoc.
The Plague of Death - A generic flu-berculosis-like disease that weakened the body and mind, eventually killing.
The Tree of Men - An awful disease that caused bones to grown and fuse into gnarled shapes. Eventually, one would become a twisted and unmoving tree-like organism, planted in the ground, with bony bark and branch, fleshy wood, and a voice like screaming wind.

Now that's all well and good, but the kicker was that all but the strongest disease-curing magic was ineffective at curing these magical diseases. Normally, that would've spelt doom for all involved, but this setting's Warforged equivalent, the Moulg, used their disease immunity to their advantage and managed to engineer a solution. They managed to combine chemistry and magic to brute-force material components that, when used to cast a lower level disease-curing spell like Lesser Restoration, would allow the spell to bypass the disease's cure resistance. Later, the chemicals used as material components were found in certain natural elements, so they could be more easily accessed by the general populace.

My question is, for each disease, what would be an interesting material component that would be difficult but possible to create in isolation, but might be found in nature somehwere? And that has some small thematic resonance with its corresponding disease?

[KorvinStarmast]

The whole point of versions of D&D having their own systems for disease is for you to use those to model disease. Which means they are cured by Remove / Cure Disease and any damage they do is either to hitpoints or ability scores, treated by effects that restore hitpoints or ability scores. 1st Edition AD&D had some specific rules for mental disorders too, but I don't remember them from the top of my head.

Anything else is overthinking it. 5e has a few insanity tables as well.
While I mostly agree with your point on overthinking, if the players show up to play Dungeons and Dragons, and find out that they are playing instead Diseases and Diagnoses they will either embrace the new challenge or get quickly bored. It really depends on the people at the table.

Discuss how you would model them and what spells would be necessary to reverse them. As a DM, that's more work than I care to do.
Two I'm thinking about: Cancer and Alzheimer's. Remove disease (or Heal) would stop things from progressing. The question I'm pondering is what would be necessary to reverse the damage? Would Restoration (or it's Greater variant), removing any physical or mental ability drain be enough? Or would one need Regenerate, to restore the parts of the body or brain that were ruined? I'm leaning toward "you need both Regenerate and Restoration," but I'm having trouble deciding.
Chemo and radiation. Got it. :smallyuk: (My sister got to 'enjoy' that a few years ago, she's still cancer free as of this year).

What do you all think, and how would you handle the topic in general? How does it fit narratively into the campaign?

{snip} I mean, D&D has supernatural diseases like mummy rot that have special rules for curing. But i don't thing modelling mundane real life diseases should get similar special treatment. The other thing to be cautious about is who at the table has a RL relative suffering from a sever disease. For them that might not be fun ...

[NichG]

If I were writing fiction rather than running a game:

Remove Disease operates by removing non-self replicating elements from a body. Doesn't do anything for allergies, heart disease, Alzheimers, celiacs, cancer, etc.

Things which restore hitpoints act like letting someone heal naturally at the level of wound sealing processes, but billions of times faster. Leaves scars and if you use this without setting a broken bone first it causes it to heal wrong.

Things which remove ability damage act like letting someone heal naturally at the level of cell replication and diversification, but billions of times faster. Can handle broken bones or recoverable organ damage but not e.g. nerve damage.

Things which remove ability drain act by returning the body to a former state in which it was functioning properly. The Restoration series does this temporally via imprints left on the soul, whereas stuff based on regeneration does it genetically (as if creating an artificial organ to transplant). Both lines have anti-aging effects, but in different ways. Restoration would work on Alzheimer's but Regeneration wouldn't without totally wiping out the person. Regeneration could cure heart disease if you removed and regenerated the heart. Pre-metastasis, Regeneration would be useful to be able to more aggressively surgically remove tumors, but post-metastasis it would just be useful as a strategy to keep someone alive with cancer indefinitely. Restoration could revert cancer, but wouldn't remove inherent propensities for it.

Probably the best cancer cure would actually be permanent polymorph or alter self effects.

[Vahnavoi]

That was my initial thought, actually, but then I got to thinking about the point of Regenerate. I mean, most of the things that Regenerate fixes don't actually have game rules for causing. For example, it grows back lost digits and limbs. There isn't any way to lose digits or limbs outside of DM fiat, unless you're a hydra. It fixes broken bones. No way to break bones, either. Perhaps even more significantly for the case of modeling real-world diseases, "ruined organs grow back." The other benefits of Regenerate (healing damage and nonlethal damage, removing fatigue and exhaustion) are extremely underwhelming for a level 7/9 spell.

So what is the point of Regenerate as a high-level spell, if all the things it fixes can't actually exist outside of fiat? And, if we're relying on fiat, when should fiat be used in the first place? Especially the "ruined organs" bit, which for some reason I'm stuck on.

Regenerate is indeed poorly written given existing injury rules. The simplest solutions are to remove it alltogether or lower its spell level. Other solutions involve either adding in an injury system capable of causing such permanent wounds, or adding in NPCs with such permanent wounds. In the latter case, PCs are not the usual recipients of the spell at all and PC-impacting effects are minor bonus - the real use is to curry favors with possible allies. For example, a kingdom needs an heir, but the king lost his nuts due to a war injury, or the queen became barren due to a childbirth - one or two uses of Regenerate can save the country from a succession crisis. Or, the champion of the realm, greatest swordsmen alive, tragically lost his sword arm in captivity, and is only half-effective in his duties as a result. So on and so forth.

[Brother Oni]

What is your goal here? For most groups, Cure disease fixing everything is just fine, because they are playing a tactical fighting game and don't want to suddenly switch to grand strategy epidemiology simulator.

But some of us like the idea of Grand Strategy Epidemiology Simulator... :smallfrown:

[LibraryOgre]

For what it's worth, the 1e DMG (https://www.drivethrurpg.com/product/17004/Dungeon-Masters-Guide-1e?affiliate_id=315505) has a disease chart, which gives diseases some characteristics... Acute or Chronic, Mild, Severe, or Terminal, all dependent on system. (There's also rules for parasitic infestation)

For example, you might say leukemia is a Chronic, Terminal disease of the blood and blood forming organs. It causes a loss of 1 point of Strength and Con per week until you're dead.

Now, you might have various methods of treating or curing that. Maybe the Healing and/or Herbalism proficiencies can draw those out, or give you a chance of stopping the degradation each week. Maybe you decide that Cure Disease isn't enough, and you need to have a higher-level spell that will Cure Terminal Disease.

In WD&D, you'd have to look at what the spells do; I think Restoration spells would be sufficient if the damage of the disease is classified as attribute damage/drain, but something like regeneration might be needed to undo actual loss of body parts.

I did some work on this for Hackmaster, creating a system for Medicine and Apothecary (https://docs.google.com/document/d/1CDO_SX7JFYWDRtc-Xe5pagmA3m4GpXTVXFjXVTQNVec/edit?usp=sharing) skills (they already had First Aid), and they have a pretty robust set of rules for diseases (https://rpgcrank.blogspot.com/2019/10/love-is-social-disease.html), which has some echoes from the 1e DMG methods.

On the topic of treating those diseases, the Guardians of the Flame (https://en.wikipedia.org/wiki/Guardians_of_the_Flame) series by Joel Rosenberg had modern college students come over to a fantasy world. One of the players had muscular dystrophy in our world, and the fantasy-side children simply could not understand such a malady... it would have been fixed by a cleric a long time ago.