UA Insanity Rules [2005 thread]
wingsandsword
Legend
It's the same rules as in d20 Call of Cthuhlu, which is largely unchanged from the original CoC rules, just now opened up to the OGL. The mechanics are dissimilar from standard d20, somewhat intentionally, to underscore how "alien" some thing the system is supposed to depict. It's actually a fairly in-depth system, so this is a very stripped-down version of it.
Every character has a Sanity score, which begins as their Wisdom score x 5.
There is the Knowledge: Forbidden Lore skill (also known as Knowledge: Cthuhlu Mythos in CoC, it's the exact same thing) which represents knowing Secrets Man Was Never Meant to Know, dark unspeakable secrets, and esoteric knowledge which will drive you insane.
Your maximum sanity is equal to 99-your ranks in Forbidden Lore/Cthuhlu Mythos. The more you know about the darkest secrets of the universe, the less sane you can possibly be, although this rarely becomes a big issue (since starting sanity for a 10 Wis character is 50, while even with 20 ranks of Forbidden Lore the maximum sanity is 79).
Every time a character is exposed to a great mental shock, such as a truly gruesome scene, high weirdness, or highly supernatural situation they have to make a Sanity check. A Sanity check is rolling percentile dice, trying to roll under their Sanity score. Various traumas have two damages, the amount of sanity damage you take if you make your Sanity Check, and the amount you take if you fail the check. On the low end is something like finding a human corpse (0/1d3) to actually seeing an Evil deity (1d10/1d100). If some form of horror becomes routine to your character (except spellcasting), you become immune from further sanity damage as your mind becomes accustomed to the horror.
As a further variant, you can actually take Sanity damage from spellcasting, to represent channelling alien forces and communing with bizarre and powerful deities.
If your sanity ever reaches 0, you're totally insane, but recoverable. At -10 sanity, you are permanently insane in the "Become an NPC" type of insanity. If you lose up to 20% of your remaining sanity within 1 hour, you also become temporarily insane, and develop some serious mental illness (there are lots of random charts) which is permanent until healed (which takes around 1d6 months of the long-term use of Heal listed below)
Successful use of the Heal skill can restore Sanity points, much like it can restore HP. A full day of dedicated care, in a safe environment away from stress and spending at 1d4 hours counseling the patient (and a DC 20 Heal check) can restore 1 point of sanity. You gain 1d6 Sanity points when you level up, and you can regain Sanity as a Story Award along with XP.
Sanity can be restored with magic, somewhat. Atonement can heal Sanity loss from evil acts, Heal restores 10 Sanity and undoes Temporary Insanity, Miracle & Wish can restore somebody to their maximum sanity (even somebody who hit -10), Limited Wish can restore somebody to maximum sanity (but not somebody who hit -10), Mind Blank makes you temporarily immune to sanity loss, the Restoration series of spells also restore increasing amounts of Sanity with each one (1d4 for lesser, 1d6/2 Caster levels for Restoration, maximum sanity for Greater).
While originally written for modern horror, there are several alterations presented to make it more usable for fantasy, like "Sanity Resistance" which reduces all Sanity Damage a target takes, equal to their Character Level, to represent becoming experienced with the world and used to strange and otherwise disturbing characters (a grick might utterly freak out a 1st level character, but a 20th level character would be used to dealing with such things).
Every character has a Sanity score, which begins as their Wisdom score x 5.
There is the Knowledge: Forbidden Lore skill (also known as Knowledge: Cthuhlu Mythos in CoC, it's the exact same thing) which represents knowing Secrets Man Was Never Meant to Know, dark unspeakable secrets, and esoteric knowledge which will drive you insane.
Your maximum sanity is equal to 99-your ranks in Forbidden Lore/Cthuhlu Mythos. The more you know about the darkest secrets of the universe, the less sane you can possibly be, although this rarely becomes a big issue (since starting sanity for a 10 Wis character is 50, while even with 20 ranks of Forbidden Lore the maximum sanity is 79).
Every time a character is exposed to a great mental shock, such as a truly gruesome scene, high weirdness, or highly supernatural situation they have to make a Sanity check. A Sanity check is rolling percentile dice, trying to roll under their Sanity score. Various traumas have two damages, the amount of sanity damage you take if you make your Sanity Check, and the amount you take if you fail the check. On the low end is something like finding a human corpse (0/1d3) to actually seeing an Evil deity (1d10/1d100). If some form of horror becomes routine to your character (except spellcasting), you become immune from further sanity damage as your mind becomes accustomed to the horror.
As a further variant, you can actually take Sanity damage from spellcasting, to represent channelling alien forces and communing with bizarre and powerful deities.
If your sanity ever reaches 0, you're totally insane, but recoverable. At -10 sanity, you are permanently insane in the "Become an NPC" type of insanity. If you lose up to 20% of your remaining sanity within 1 hour, you also become temporarily insane, and develop some serious mental illness (there are lots of random charts) which is permanent until healed (which takes around 1d6 months of the long-term use of Heal listed below)
Successful use of the Heal skill can restore Sanity points, much like it can restore HP. A full day of dedicated care, in a safe environment away from stress and spending at 1d4 hours counseling the patient (and a DC 20 Heal check) can restore 1 point of sanity. You gain 1d6 Sanity points when you level up, and you can regain Sanity as a Story Award along with XP.
Sanity can be restored with magic, somewhat. Atonement can heal Sanity loss from evil acts, Heal restores 10 Sanity and undoes Temporary Insanity, Miracle & Wish can restore somebody to their maximum sanity (even somebody who hit -10), Limited Wish can restore somebody to maximum sanity (but not somebody who hit -10), Mind Blank makes you temporarily immune to sanity loss, the Restoration series of spells also restore increasing amounts of Sanity with each one (1d4 for lesser, 1d6/2 Caster levels for Restoration, maximum sanity for Greater).
While originally written for modern horror, there are several alterations presented to make it more usable for fantasy, like "Sanity Resistance" which reduces all Sanity Damage a target takes, equal to their Character Level, to represent becoming experienced with the world and used to strange and otherwise disturbing characters (a grick might utterly freak out a 1st level character, but a 20th level character would be used to dealing with such things).
