Characters in games will encounter stressful situations, and monsters which could potentially bring them over the edge and slip into insanity. The mere presence of some creatures can terrify characters into losing their mind as well.
Sanity Damage cannot be increased by effects which modify damage unless an effect specifies it modifies Sanity Damage.
Stress: 10 + Smarts + Resistance + ¼ Luck
This score determines a character’s short term sanity and composure. Sanity is first applied to Stress until they hit 0 Stress. After which it starts applying to the character’s Sanity stat.
You regain 1 Stress per hour of sleep or rest.
Sanity: Smarts + Resistance + ¼ Luck
This score is how much the stress of the world has permanently impacted the character. For each point of Sanity a character loses, they gain a random mental illness as determined by the roll-able chart.
If a character's Sanity reaches 0, they’re completely lost to insanity and become completely unplayable until cured of their insanity. Enemies who reach maximum in their Sanity stat attack everything and anything within reach (including themselves and allies).
Characters regain 1 point of Sanity per every 1 week of rest without a stressful situation occurring. A character’s randomly rolled mental illnesses only go away once their Sanity stat is completely cleared.
Mental Disorders:
Name: Hallucinations
Descriptions: The character is plagued by seeing things which aren't actually there, straining their perception of reality. While afflicted with Hallucinations, the character takes a -10 to all Awareness checks. While on certain drugs however (such as LSD, DMT, and Ketamine) the character can manage these hallucinations while on the effects, reducing the penalty to -5 instead and gaining a +5 to Deception checks for the duration of the drug.
Name: Schizophrenia
Descriptions: Chemical imbalances which result in confused and erratic behavior. Characters afflicted with schizophrenia have access to a reality beyond, tainting their ability to distinguish what's real and not. This access to a strange, 'other' force, granting a +5 to all magic-based effects (such as spellcraft rolls, Knowledge (Magic), and spell attacks) however for each round in combat a schizophrenic is engaged in, they add "1" to a "Schizophrenia Counter", with the maximum of their Schizophrenia Counter equal to Level + (1/2 Smarts). Once this reaches its maximum, the character flies into a rage and attacks enemies and allies alike.
Name: Aphasia
Descriptions: The character can no longer communicate with any spoken languages they know. They must use sign language, or pictures.
Name: Echopraxia
Descriptions: Every 1d5+1 rounds, a character with Echopraxia must repeat an action they took in their previous round. (For example, after 4 rounds the character with Echopraxia attacks a foe. On their next turn they want to move, however they must also attack the foe again (even if they're already slain), or another target within reach). This is up to the GM's discretion.
Name: Logorrhea
Descriptions: Characters with Logorrhea cannot communicate properly or make Deception/Persuasion checks while in the middle of combat, and when making a Deception or Persuasion check they take a -5 penalty when doing so.
Name: Autophagia
Descriptions: When afflicted with Autophagia the character will try to bite and gnaw at themselves when unable to keep themselves occupied. If in combat and the character is unable to attack a foe, they instead bite and gnash at themselves and take 1d5 points of bleed damage for a number of rounds equal to their Strength or Agility (whichever is higher).
Name: Bipolar
Descriptions: While in combat Bipolar characters take a -1 penalty to all actions for each round in which they do not attack an enemy.
Name: Body Dysmorphia
Descriptions: A character afflicted with Body Dysmorphia if they do not attack a foe on their turn during combat either attack themselves, or if the option is available they instead change their appearance through a spell or special ability.
Name: Depression
Descriptions: Every other round during combat the character must either take a -1 penalty to all actions they take, or lose their turn. The penalty stacks upon itself (to a maximum of -40), and the instance the character chooses to instead lose their turn, the penalty resets back to 0.
Name: Fugue
Descriptions: When taking a movement action on their turn during combat, if the character is moving half their move speed or more they must roll a 1d5. 1-2 is diagonally to the left instead, 3 is the direction they want to go, and 4-5 is diagonally to the right instead.
Name: Hypochondria
Descriptions: Every time a character with Hypochondria takes damage in combat they use healing items, spells, or abilities on themselves regardless of the severity of the injury. If they cannot, they lose their turn (however they do not continue to lose subsequent turns thereafter until they take damage again).
Name: Insomnia
Descriptions: Instead of the standard 8 hours of sleep, the character sleeps for 12 hours. If they sleep for between 8 hours to 11 hours they gain the full benefits of sleeping save that they wake up fatigued.
Name: Megalomania
Descriptions: At the start of combat the character must make a Persuasion check against the closest person in an attempt to intimidate them. If there are no people they can see in order to intimidate, they instead lose their turn.
Name: Multiple Personality Disorder
Descriptions: The character has 4 additional unique personalities in addition to their own, and these personalities will take control at a whim. During combat at the start of the character’s turn they must roll a 1d10. 1-2 means they’re themselves, 3-4 means they’re violent and attacks anyone in sight, 5-6 means they’re incredibly depressed and refuses to act, 7-8 means they run away from all enemies, and 9-10 means they’re convinced they’re on the other side, and attack any allies within range.
Name: Post-Traumatic Stress Disorder
Descriptions: At the beginning of combat the character is stunned for 1 round, and takes a -5 penalty to all non-attacking actions for 1d5-1 rounds thereafter (minimum of 0, or in other words taking no penalty immediately after).