The base Sanity score for a humanoid creature is 70. To this, the creature's wisdom score is added. A creature's sanity at any one time cannot exceed its maximum sanity. An increase or decrease in wisdom alters the creature's maximum sanity, but not their current sanity. It is usually impossible to increase a creature's maximum sanity without increasing wisdom, though some powerful magics such as Wish may allow it to be expanded.

Each person's insanity takes a different form, that manifests throughout the different stages of insanity that a sufferer goes through. For example, if the general type of insanity is "schizophrenia": an ongoing insanity could be (mild) occasional voices and acting strangely around people, (moderate) claiming to speak to someone who does not exist and becoming violent when questioned about it, and (severe) constantly hearing voices and feeling compelled to act upon what they tell him to do. His temporary or permanent insanities would be more pronounced versions of this, for example he is "taken over" by one of his personas.

Ongoing Insanity is the gradual buildup of neuroses that a low sanity garners. Even if they pass all their checks against temporary insanity, having a low sanity score reflects the destabilising of the psyche - ongoing insanity generally takes the form of nervous symptoms and compulsions that are related to their insanity. These are reflected in the form of three thresholds. Mild Insanity begins to take hold when sanity falls below 75, and is generally quite minor - nervous tic, slight paranoia, etc. Once sanity falls to 50, this worsens to Moderate Insanity, at which point aspects like paranoia and compulsive behaviors become more marked and obvious. Finally, once sanity falls to 25, Severe Insanity sets in - at which point they are near permanent insanity. Their compulsions and other insane actions become very noticeable, and there is no doubt that they are insane.

Temporary Insanity can manifest in various ways, and is what in modern times would be called a "psychotic episode" - a complete (but temporary) break from reality. When a character first loses enough sanity to bring them below 75 sanity points, they have a chance of being afflicted with temporary insanity. This chance is 1% for each point below 75 they are. If they fail, they become temporarily insane. They must make this check again each time they lose sanity while their sanity is still below 75.

When someone first becomes afflicted by temporary insanity, their sanity score immediately drops by 3d4 points. People afflicted with temporary insanity count as sanity 0 as long as they are insane, but their actual sanity score does not change any further. Note that because a temporarily insane person's sanity counts as 0, they do not gain sanity by resting. If untreated, temporary insanity persists for a period of time that depends on their Wisdom - see the Charm Person table (using Wisdom instead of Intelligence) for the interval between checks. When this time period elapses, they may roll a new save to see if their insanity continues.

Temporary insanity can manifest in many different ways, depending on the personality of the character. It will always be related to the nature of their ongoing insanity, however. Some examples include:

A skilled healer can adminster therapy to cure temporary insanity, and many alchemical treatments and spells can reverse it. Treatments that do not explicitly cure temporary insanity but that increase your sanity score do not automatically heal temporary insanity, but they do allow a new save against it.

Permanent Insanity is almost irreversible. Only the most deadly medical treatments have a hope of curing it. Likewise, only the most powerful magics - such as Wish - can remove this insanity, for it is an affliction bred of a shattered and disordered mind, and is not a simple curse that can be reversed by petty magics. Permanent insanity happens when a character's sanity drops below 0. Subjects who have permanent insanity can undergo magical and psychological treatments, but until their permanent insanity is cured their sanity cannot be brought above 0. If a character is cured of permanent insanity, their sanity immediately rises to 1. Permanent insanity can only be cured by a Limited Wish or Wish, divine intervention, or certain alchemical treatments.

Magical Insanity uses the arcane to manifest many of the effects of ordinary insanity. The main difference is that these effects are the disorder caused by a magical curse, rather than a mind that has broken under the strain. As such, magical insanity can be cured by the following magical means: Restoration, Heal, Limited Wish, or Wish. Depending on the nature of the effect, Dispel Magic or Remove Curse may also work. Although magical insanity is not actual insanity, for each week the afflicted spends under the effect of magical insanity their actual sanity score reduces by 1. This reduction cannot cause temporary insanity, as the subject is already insane. Magical insanity duplicates the effects of permanent insanity.

Sanity Losses

Obviously, sanity reducing effects or monsters have their own jurisdictions, but there are many "everyday" occurences that can cause one to lose some of their sanity. Trying to list each of these here would be an unnecessary admin job for the DM, so it's largely left up to DM discretion. As a general rule, any kind of serious trauma - from losing a friend to being brought back from the dead - could result in the loss of some sanity. There is no universal scale, however: a normal person could well lose sanity upon seeing a goblin slain, but a hardened adventurer is unlikely to.

Some examples of sanity losses:

Recovering Sanity

Sanity Sleep in a Safe Place Taking a Break In Asylum
Above 70 1/day 30/month 30/month
Above 50 1/week 10/month 15/month
Above 30 - 3/month 10/month
Above 10 - 1/month 5/month
Above 0 - - 1/month
Below 0 - - -

Normal sleep, which does not restore sanity, is outside, in a public place, or anywhere else where danger or distractions could ostensibly strike. Sleep in a safe place is somewhere heavily guarded, in a temple or inn, or in your own home. In order to take a break, you must lose no sanity during that month and you must do no adventuring, strenuous work or heavy research. Temporarily or permanently insane people don't gain ever sanity by resting.

Sleep deprivation: For the first 24 hours of sleep deprivation, the character will simply gain no new sanity. On the second and third days, they will begin to lose 1d6 sanity per day. On the fourth to seventh days, they will lose 1 point of sanity every four hours (6 points of sanity per day). Finally, after seven days have passed, they will lose 1 point of sanity every two hours. This continues until they get a good night's sleep, or until they become insane.

Mental Care

A healer (someone with the Healing NWP) can attempt to adminster immediate treatment to snap someone out of temporary insanity by talking with them, if they are trained in doing so. Bonuses may be applied if, for example, a priest of Enod is attempting to counsel someone who worships the Trinity. They must be able to talk to them in an uninterrupted fashion for one full minute (1 round). This can only be attempted if there is no current threat or stress being placed upon the healer or the patient. If the proficiency check is successful, the patient will immediately gain a single point of sanity, allowing them to make the check against temporary insanity once more. This short-term treatment can only be adminstered once per temporary insanity, and if it fails more long-term treatment must be sought out. Emergency short-term treatment can only be adminstered to someone with temporary insanity.

If a healer spends an hour a day with a patient, he or she may talk with them, allowing them to make a Healing check. On success, the patient gains 1d6 sanity; on failure, they lose 1d4 sanity as they regress deeper into their condition. A successful check allows temporarily insane patients to make the temporary insanity check again - if successful, they snap out of it, but if it fails then the 1d6 sanity that was restored is reversed, and they lose an additional 1d4 sanity. This type of care can be used on patients with permanent insanity, but it cannot bring their sanity above 0 until it is cured in some other way.

There are rare places, called Asylums, that are designed to heal and hold people who are under the effects of insanity. They are well-stocked with skilled healers and clerics. In such a place, they can adminster advanced treatment and facilities over the course of a month that is very adept at curing insanity. Spending one month in an asylum automatically cures temporary insanity. Furthermore, time spent in an asylum restores large amounts of sanity. Time at an asylum is very expensive, however, costing from 300 to 1,500 gp per month, depending on the asylum and the patient. Permanently insane people can be admitted to an asylum at a reduced cost (half price), but it will not improve them: they will simply be held and cared for.

Alchemical Treatments

Arthorvin: A fragrant gray powder made from rare magical plants, Arthorvin requires an ASL of 0 to produce, and requires access to the common Kingsfoil found in deserts and scrubland, as well as the Lenwyllyn, cultivated in elvish forests. Arthorvin provokes a calm state of mind for 2d4 hours that will protect against the effects of temporary insanity, and allows a saving throw for those who already have it. Furthermore, it will increase current sanity by 1. 50 gp per dose. It can only be used once a day.

Carthagu: A pale green elixir designed to be drunk, it must be kept in absolute darkness to be effective. It is made by any alchemist with an ASL of 1 and both a supply of powdered starmetal and the bonemeal of an inherently magical creature. Carthagu, when taken, will have the effect of sending the drinker into a deep and restless sleep from which they cannot be awoken for 2 hours. During this time, they will be wracked by spasms and extreme pain that will reduce them to 10% of their hit points, but by the end of this time they will have gained 3d6 points of sanity. 500 gp per dose.

Mertoran Leaf: A leaf found in the desert and available in most apothecaries, it can be properly dried and prepared with an ASL of 0 or the Herbalism NWP. Imbibing dried Mertoran Leaf has a cumulative effect. The first week it is imbibed, it has a 5% chance to remove a temporary insanity from the patient. Every week thereafter that it is taken, it will increase this chance by 1%. A lapse in dosage reduces this chance by 1% per day. Mertoran can be used preventatively - allowing you to roll to avoid temporary insanity that would otherwise begin to affect you. 5 gp per dose.

Patience: A thin gray liquid designed to be place on a needle, dagger or blade, Patience can be created with an ASL of 0 and access to both the poison glands of a giant spider and the blood of a red dragon or other heat-loving reptile. Patience acts as a poison; the person who takes it into their blood stream must make an immediate saving throw vs. death; if they fail, they immediately fall unconscious and their sanity, if below 10, is restored to this level. If their sanity is between 10 and 30, it is restored to 30. Otherwise, this drug has no effect. Patience cannot be used to cure permanent insanity, but the sanity boost will give a new save vs. temporary insanity. When the save against Patience is failed and their sanity is restored, the subject permanently loses 1 point of Constitution. 300 gp per dose.

Zixalix: Prepared with an ASL of 3 and access to a variety of alchemical herbs that require a proper alchemical garden or a vast store of reagants - the herbs to create it come to at least 1,000 gp in value. Zixalix is a potent but dangerous mixture of herbs, dried and baked into a single hard capsule. When eaten, the patient must take a system shock roll or die instantly. If they succeed, however, its effects are as follows: it will remove permanent insanity, restoring sanity to 1 point. If the patient is not permanently insane, then it will remove all temporary insanities and restore 5 points of sanity. If the patient has no indefinite insanities, it will restore them either to a sanity of 70 or to their maximum sanity, whichever is lower.