Insanity

Each character's maximum sanity points are based on their Wisdom attribute and are tracked in the XP field of their character sheet. 

Sanity Points = Wisdom or 20 - Eldritch Lore skill (whichever is lower) 

Losing half or all of their total sanity points causes the character to gain a derangement rounds (stacks with madness if the same). 

Eldritch Lore

Maximum Sanity Points are capped at 20 - Eldritch Lore skill. The skill limits how mentally sound a character can get. However, the skill is also a boon and allows characters to use and interact with eldritch magic and may affect how well they can use them and how certain beings may react to them.

A character can't directly add skill ranks to the Eldritch Lore skill. Instead their skill level is determined by their exposure to Eldritch effects, magic, beings, and knowledge. Some of these are the result of direct character choices. Other times it is the result of merely being in the wrong place at the wrong time.

Sanity check is a d20 roll. The DC of the roll is set by the character's existing sanity points plus or minus modifiers. Unlike every other roll in this game, rolling at or below your existing sanity points is a good result, while rolling above means becoming mad and a loss of sanity points, creating a downward spiral and making future tests harder.

Test Difficulty Class

DC = Current Sanity Points +/- modifiers

Success (Result is under or equal to DC)

Character doesn't always get away without a hitch. It can simply mean that the sanity loss is halved.

Failure (Result is over DC)

The character takes full sanity loss, enters/progresses into the Madness Track.

Truly horrific experiences can put the victim further down the madness track than just one step.

Continued sanity loss progresses them further down the track.

Critical Failure (Natural 20)

The same as a failure, except the character also gains a new derangement.

Type: Disease

Save: Sanity (see below)

Track: Mental

Frequency: 1/day

Effect: Special Madness progression track (see below)

Cure: 2 consecutive saves (Any Phobias or Manias remain.)

Track

Healthy | Latent | Weakened | Impaired | Befuddled | Disassociated | Comatose | Dead

Latent

• The victim can pass on contagious diseases but suffers no ill effects outside of unnerving mannerisms.
• All who can hear or see the victim and are less progressed in their Mental Disease Track get a -2 penalty to their sanity check DC, making checks harder to pass. This is a cumulative effect. Meaning that madness drives madness in others.

Weakened

• They experience difficulty sleeping and frequent hallucinations.
• May lose control for one round.
• One existing derangement manifests itself.
• If deranged, they can become shaken or panicked. (You take a –2 penalty to ability checks, attack rolls, saving throws, and skill checks.)
• They are more susceptible to mind-affecting effects with a -2 penalty.
• DCs of their spells and special abilities decrease by 2. They can no longer cast Their highest level of spells (if any).

Impaired

• Hallucinations interfere with regular activities. 
  
• May lose control for 1d6 rounds.
• All existing derangements manifest themselves.
• If deranged, they can become shaken or panicked. (You take a –2 penalty to ability checks, attack rolls, saving throws, and skill checks.)
• The victim is flat-footed. (You take a –2 penalty to AC, and you cannot take reactions or make attacks of opportunity.)
• They are more susceptible to mind-affecting effects with a -4 penalty.
• They no longer add their mental ability score modifiers when calculating number of uses per day of abilities dependent on those scores, including bonus spells per day.
• The DCs of their spells and special abilities decrease by an additional 2. They can no longer cast their 2 highest levels of spells (if any).

Befuddled

• Hallucinations invade thought. The victim begins losing grasp of thought, reality, and self.
  
• The character becomes deranged for 1d6 rounds, which can mean anything from amnesia to developing permanent phobias or manias.
• Disassociated
• The victim is almost entirely disconnected from reality. Their mind filters and twists all external stimuli into strange forms.
• They can no longer tell friend from foe and can’t willingly accept any aid (including healing) from another creature unless they succeed at a Will save against the disease’s DC. 
• The character becomes deranged until healed, which can mean anything from amnesia to developing permanent phobias or manias.

Comatose

• A victim rendered comatose by a mental disease has lost all grip on reality and entered a dream world. They can’t be woken.

Dead

• The victims face and body contorts in a horrific pose and they die. The means of their death tests the sanity of all allies who can see or hear them, forcing them to make sanity rolls.

Phobias and Manias

While the character is sane, a phobia or mania acts solely as a roleplaying trait. For example, if the player wishes for his or her (sane) character to overcome claustrophobia and crawl through dark tunnels, the phobia won’t prevent this. However, while the same character is mad, the phobia or mania takes on a greater significance.

Phobic and Manic Responses While Mad

Direct exposure (close physical proximity) to the subject of the phobia causes character to be first shaken and then panicked; equally, exposure to the source of a mania causes an obsessive reaction (as panicked except focused on mania instead of fleeing).

For phobias, characters are shaken as long as they are exposed the the source of phobia. This penalty does not apply to Sanity rolls or reality check rolls.

While in a state of madness, being exposed to the subject of their mania will cause an overwhelming response in the character. If the GM prompts the player towards some form of behavior appropriate to their mania, the character will be shaken until the obsession has been indulged in some manner, or the character is well out of range of the stimulus. For example, while in a place that serves alcohol, a dipsomaniac would shaken unless taking a drink. Of course characters who fully succumb to their drug craving will be subject to the drug’s effects, such as drunkenness or altered states of consciousness. In such situations the GM may alter the level of difficulty of certain skill rolls (or impose a penalty die on opposed skill rolls) depending on the situation and state of the character.

Characters who do not or are not able to prevent further exposure to the source of panic or continue not to indulge a mania become panicked.

Delusions and Reality Checks

While not in control of the character’s actions, the GM is free to present a character suffering underlying sanity loss with delusional sensory information at any time. The only way for the player to be sure of what his or her insane character is seeing, hearing, touching, feeling or smelling is to make a “Reality Check”.

Delusions have greater impact when they have some relevance to the character. A great way to do this is to refer to the character’s backstory and use some aspect as inspiration for delusions. A character’s late spouse calling on the telephone is much more engaging than random delusions.

Reality Check Rolls

While reality checks are only usually called for on behalf of mad characters, a player might call for one if they wish to “see through” what they believe to be a hallucination or illusion. To perform a reality check, the player makes a Sanity roll:

Failure

Lose 1 Sanity point. Character immediately becomes deranged if the character is suffering from madness. Any delusions are not dispelled.

Success

The character sees through any delusions, and the GM must describe what the character genuinely perceives.

On making a successful reality check roll, the character should see things as they really are and will be resistant to delusions until losing further Sanity points (thus pre- venting the GM from constantly throwing delusions at a player).

Diseases, drugs, and poisons can be cured if they are treated before the victim reaches the end state. In the case of a disease, the victim must fulfill the conditions in the disease’s Cure entry (usually succeeding at one or more consecutive saving throws). Each time they do so, they moves one step back toward healthy; once they reach healthy, they are cured. However, any derangements acquired while going mad remain and have to be cured separately.

Successful application of the Medicine skill during victims saving throw provides a +4 circumstance bonus to the save.

DC: 25 + victim's level - victim's sanity points

Healing Sanity Damage

If the character is no longer mad, they recover sanity at a rate of 1/day.

Successful use of the Medicine skill upon the character enables them to regain sanity at a rate of 2/day. If successful by 5 or more, add the healer's Intelligence bonus to the amount of sanity recovered.

DC: 25 + victim's level - victim's sanity points.

Healing Derangements

The best way to heal derangements such as amnesia, phobias or manias is through medicine combined with long rest, while under the care of a trained psychoanalyst. This typically results with the character having to regularly take prescribed medicine, use medical devices, or use other coping mechanisms over a long period of time.

More severe methods that involve implants, electroconvulsive therapy, or brain surgery also exist, but they are not without their own side-effects.

In an emergency sedatives, stimulants, hypopens, or even drugs may be able deal with certain conditions, albeit typically introducing other complications.

Phobias and Manias

Successful use of the Medicine skill upon a mad character enables them to temporarily ignore a phobia or mania.

DC: 25 + victim's level - victim's sanity points

Delusions

Successful use of the Medicine skill will allow an insane character to see a delusion for what it is.

DC: 25 + victim's level - victim's sanity points