Characters of all kinds will experience stressful situations throughout their lifetime, between fights for their life to encountering horrific supernatural entities, the world is a scary place both from that which is natural and that which isn't. And these periods of terror wear on the mind over time, tearing down its barriers and sending them into a state of shock and panic.
Most of the time, things go against Resolve and instead test one's mettle to stay or leave when encountered with a truly stressful situation. However other effects immediately attack one's Sanity, usually due to supernatural or magical effects.
The following are scenarios where a character may be forced to risk taking Sanity damage (up to GM's discretion);
Witnessing a gruesome murder or other vile gore
Witnessing a terrifying creature (this is relative to one's character)
Being accidentally responsible for the death of someone
Committing murder despite being desensitized to violence
Mental illnesses are inflicted upon a character when their Sanity reaches 0, or through other events. These debilitating mental disorders have varying effects, some worse than others.
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 Sense skill checks. While on certain drugs however (such as LSD, DMT, and Ketamine) the character can gains a +5 to Trickery checks for the duration of the drug.
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 skill checks (such as Spellcasting) 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 (Common Sense x 2). Once this reaches its maximum, the character flies into a rage and attacks enemies and allies alike.
Descriptions: The character can no longer communicate with any spoken languages they know. They must use sign language, or pictures.
Descriptions: Every 1d6+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.
Descriptions: Characters with Logorrhea cannot communicate properly or make Social skill checks while in the middle of combat, and when making a Social skill checks they take a -5 penalty when doing so.
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 1d6 points of bleed damage for a number of rounds equal to their Power + 2.
Descriptions: While in combat Bipolar characters take a -1 penalty to all actions for each round in which they do not attack an enemy.
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.
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.
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 1d6. 1-2 is diagonally to the left instead, 3-4 is the direction they want to go, and 5-6 is diagonally to the right instead.
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).
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 but still suffer Unconsciousness at Low Intensity for 1 hour.
Descriptions: At the start of combat the character must make an Intimidate check against the closest person. If there are no people they can see in order to intimidate, they instead lose their turn.
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.
Descriptions: At the beginning of combat the character is stunned for 1 round, and takes a -5 penalty to all non-attacking actions for 1d6-1 rounds thereafter (minimum of 0, or in other words taking no penalty immediately after).