Maladies are elements of the soul (Health, Phost, Trist, etc.) that have been damaged in some way. They have the Malady aspect, which changes the way the soul element functions.

Many slots do not accept maladies. You cannot use them in the Consider verb, the Talk verb, or any building slots. So, you can't use them to boost an assistant's attributes, open a package, recruit a villager, work in the inn, etc. However, workstations do generally accept maladies... which is how they become useful! More on that in a bit.

Maladies also have changed principles. For example, Phost normally has Lantern 2, Sky 1. Maladied Phost just has Lantern 1. Some maladies have an entirely different principle than they normally do - Wist, which is normally Lantern 1, Winter 2, changes to Scale 1 when maladied. There's a table below listing all of the maladies and their principles.

While the game warns that "there can be serious consequences if [maladies] go untreated", as of the time of this writing, there are no increasing consequences for having maladied soul elements. However, certain maladies can spread to any books you handle with that soul element. More on this later.

You typically gain maladies from cataloguing or reading contaminated books. Some books (chosen somewhat at random) will have a curse, contamination, infestation, or the like, indicated by an additional aspect on the book. Each contaminated can malady two different types of soul element. If you catalogue, read, or attempt to master the book using one of those soul elements, that soul element will become maladied. Contaminations can be removed from books by using a skill with the relevant removal aspect and intensity 7 of the principle specified on the contamination aspect.

There are some other, less common ways to obtain maladies:

• When you attempt to master a book without quite enough of the needed principle, you are granted three opportunities to make up the difference. Sometimes, these opportunities allow you to add an additional soul element. If you do so, and you still fail to master the book, that extra soul element may become maladied.
  
• (Numa spoilers.) If you work at the inn during Numa, one of the results is that the soul element you used has a high chance to become maladied.
  
• There may be other ways that I haven't yet encountered or have forgotten - feel free to comment if you've found one!

Once you have a malady, you can cure it and return it to normal by resting in your bed with a beverage and the relevant principle at the necessary intensity, as indicated by the aspect on your soul element card (and in the table below).

While maladies cannot be used for most types of work, there are some kinds of work that will accept a maladied soul element.

Maladies can be used to:

• Catalogue books.
  
• Reread mastered books to generate a memory.
  
• Master books, if you can meet the requirements.
  
• Craft, if you can meet the requirements.

Notably, when using maladies to do any of these things, maladies do not become fatigued, meaning you can use them over and over. If working with soul elements normally "costs" one soul element, working with maladies is free! All it costs is the time, and potentially going a bit out of your way to make use of stations that accept the malady's principle.

However, you do want to be sure that the malady you're using won't spread and infect the books you handle with it. There's a table below, but the short version is that your malady should be a Fifth Eye Cursed Phost or Fet, or a Sthenic Tainted Shapt or Health (or a malady that doesn't list a source).

Generally, maladies fall into two categories: maladies that can spread to books and should only be used for crafting, and maladies that can safely be used for all purposes.

• Fifth Eye Cursed Fet & Phost and Sthenic Tainted Shapt and Health can safely be used for all purposes. Some maladies also don't say what caused the malady, and those are safe to use for all purposes as well.
  
• All other maladies should only be used for crafting, as their condition will spread to any books you handle with them.

Ideally, malady an element of the soul that you have multiple copies of. Health is the obvious choice to start, though later I'd recommend Shapt (since you can't use it for scavenging the beach/moors or harvesting from gardens). If you're going to dedicate a malady solely to crafting, Ereb is also a good choice (since you likewise can't use it for scavenging, harvesting, or working at the inn).

Try to avoid maladying upgraded soul elements, as they're more difficult to cure.

How many maladies to have is up to personal preference. In the early game, when you're just using them for cataloguing and rereading books, I usually only try to have one at a time; I don't find that having more is all that useful. Later on, when you're using them more for crafting, having multiple can be handy.

Find a desk that accepts your malady, and try to do most, if not all, of your cataloguing and memory generation/rereading with your malady at that desk. These activities don't require specific principles or specific intensities; they just need any soul element. Maladies are perfect for this, and it saves your healthy soul elements for other work that cannot be done with maladies or requires higher principles. You also don't need to worry about unexpectedly getting a new malady from cataloguing books, since the soul element you're using is already maladied!

While you can use maladies to master books and for crafting, doing so is a bit tricky. Both activities require specific principles at specific intensities, in addition to needing a workstation that accepts both the principle you're focusing on and your malady. It's worth doing when you can, of course, and later in the game, maladies can be very useful for the tier 5 'prentice recipes, but for quite a while, you'll mostly just use your malady to catalogue and reread books.

You can also use maladies when leveling up a skill. The malady's principle needs to be one of the skill's two principles. (Remember that a malady's principle is often different from the healthy soul element's principles!)

Because maladies don't fatigue, you can use them throughout the day. Normally, you want to have all your work done by dawn, so that your fatigued souls are refreshed. This doesn't apply to maladies. This means, in particular, you can set a malady to reread a book for a useful memory just after the "night has fallen" notification pops, and that memory will be ready just after dawn. Combine that with dreaming on a memory when night falls, and you can start the day with two memories of your choice!

Below is a table of maladies, their principles, their causes, and their cures.

Note that Mettle cannot become maladied.

• Maladied base soul elements, such as Chor, require intensity 5 of the curing principle to cure.
  
• Maladied soul elements that have been upgraded once, such as Chor+, require intensity 7 to cure.
  
• Maladied soul elements that have been upgraded twice, such as Chor++, require intensity 9 to cure.
  
• Maladied soul elements that have been upgraded thrice, such as Chor+++, still require intensity 9 to cure.
  
• Regardless of upgrades, the maladied soul element will always have its principle at intensity 1.

Many thanks to the Rowenarium for providing some data needed to fill out my table.

If you notice an error or omission in this guide, or just have something to add, please feel free to comment!

Last updated for game version 2023.II.D.4 "Daymare" update