Sanity

Being alone in the wilderness will start to take its toll on the character after a few days. You will see how much it affects the character through sanity. Sanity represents the character's mental state in the game. It is measured numerically. When &le; 30, the character becomes insane, when  &ge; 35, the character becomes sane. Players can gain and lose sanity in various ways.

A small animated arrow appears in front of the brain, showing when sanity is increasing or decreasing. A bigger arrow means that your sanity is increasing/decreasing faster. As sanity decreases, strange things start to happen: the player's vision becomes shaky, over-saturated, and bright, whispers are heard, and shadowy monsters (called Hallucinations) start to appear. When the character becomes insane, the hallucinations become aggressive and start to attack.

Generally, being in close vicinity to various monstrosities, and eating bad food decreases sanity - while wearing fancy stuff, eating good food, and sleeping increases sanity.

Due to the fact that several magical items decrease sanity when used, it could be thought of as a sort of mana that is depleted by magic use. However, having little sanity brings about its own benefits (for example getting Nightmare Fuel for powerful weapons and armor.)

Temporal Sanity Table

 * Monsters drain more sanity when playing as Wolfgang and less as Wendy. Willow have less maximum sanity (120) and Wickerbottom has more than average (250). WX-78 has variable amounts of maximum sanity depending on how much he is upgraded (100-300). Wilson, Wendy, Wolfgang, Woodie and Maxwell all have a maximum of 200 sanity. Wes has 150 sanity. Maxwell's sanity goes up 20 points per minute by default.

Insanity

 * Lighting starts to become desaturated. ( &le; 100% sanity) Near total insanity, it even dims.
 * Mr. Skits starts to appear &le; 160
 * Eyes will appear in darkness. ( &le; 60% of max character's sanity)
 * The screen starts to shake (nausea). ( &le; 60% of max character's sanity)
 * Shadow watchers and night hands start to appear at night. &le; 130
 * Crawling Horrors and Terrorbeaks will become visible ( &le; 100).
 * You start to hear the insanity ambience ( ≤ 50% of max character's sanity) but it's so quiet, you can only hear it with headphones or by turning the volume up. It gets louder when your sanity drops.
 * Rabbits will turn into beardlings. Bunnymen turn into Beardlords. ( &le; 40% of max character's sanity)
 * You begin to hear whispering. ( &le; ?% of max character's sanity)
 * The screen is surrounded by black tendrils. When insane ( &le; 30), the tendrils turn red, presumably indicating a headache.
 * Crawling Horrors and Terrorbeaks will start to attack ( &le; 30).
 * Your character starts holding his/her head in their hands and nod back and forth.
 * In the options you can turn off distortion, resulting in the blurry effect on the edges not playing.