Hungry Void

Some places in the unending night below sap existence as well as light and warmth. These hungry voids give creatures in them a disorienting feeling of falling away from their bodies. Light cannot dispel this effect because it is the area and not the shadows that unravel the threads of life. A creature in a hungry void is closer to death than elsewhere.
    A hungry void typically fills an area 5 to 10 squares on a side, but some hungry voids—said to reflect the sites of epic battles in the Underdark—can be much larger. A hungry void can be identified with a DC 20 Dungeoneering check.

    Effect: Bright light in a hungry void is automatically reduced to dim. A creature in a hungry void takes a -1 penalty to death saving throws. A bloodied creature that ends its turn in a hungry void square takes 2 necrotic damage per tier.
    Usage: A hungry void accelerates the slide from bloodied to unconscious to dead, making any dangerous encounter more terrifying for the characters.

Published in Underdark, page(s) 120.