These places are accursed morasses of depravity, nexuses of lingering hate and festering evil that bode ill for the pure-hearted who trespass upon them.

A well of evil is typically a single room, cave, or structure, though it can expand to fill an area with a radius of up to 2d4 × 10 feet. Good-aligned creatures can feel the powerful evil presence tainting a well of evil, and such creatures that approach within 30 feet must succeed at a DC 15 Will save or become sickened and refuse to enter the location for 1 hour. A successful Will save negates these unfortunate effects, but if the creature actually enters the location, it becomes sickened with no save. Within a well of evil, the DC to resist negative channeled energy increases by 2, and good-aligned creatures take a –2 penalty on saving throws against curses, corruptions, madnesses, spells with the evil descriptor, and the effects of haunts. Haunts that lurk within wells of evil also gain a +4 bonus on their Initiative checks and to Perception check DCs to notice them.