when a character experiences extreme emotional trauma or turmoil, otherwise known as a test of sanity, the character needs to roll a wisdom will save with a DC determined by DM. upon a fail, they lose sanity and now need to calculate it.
you must determine your sanity pool. This is calculated by 50 + 10 times your wisdom. Sanity is lost in increments of either 1d4, 1d8, 1d12, or 1d20 depending on the severity of the experience.
At any point of being mentally unwell, the DM can force the player to make a wisdom will save if they feel like there’s a point where the character’s sanity is being tested. The criteria of the sanity testing and DC of the save is up to the DM, but upon a failure the DM can choose from the sanity loss dice options and whatever’s rolled is taken from the character’s sanity.
Mentally Unwell
Once you’ve lost any sanity you become mentally unwell, meaning you are at least not at the level of mental wellness that you should be. Gain a -1 to will saves, this won’t go away until you are considered mentally well (meaning that you won’t need to keep track of your sanity.)
Mentally Ill
If you only have half of your sanity pool remaining, you gain one of the listed mental illnesses. Gain another -2 to will saves, this and the mental illness won’t go away until you are considered mentally well.
Clinically Insane
If you reach 0 sanity, your character’s mind fully breaks beyond normal recovery. The character experiences a mind death and is regarded as a dead character, meaning you need to roll up a new one.
Theoretically, someone else can try to find a way to restore you to at least mentally ill if they are able to at least restore a point of sanity to you. If you are able to regain a point of sanity you go back to being mentally ill but also gain a -3 to will saves until you are considered mentally well.