The Feywild and Shadowfell bleed into the natural world, and vice versa. There are tales about travelers vanishing into Faerie while walking a lonely road at night. Likewise, most rural communities know well there are nights when the dead walk and when the shadow reaches out from the underworld to snatch the living.
Planar bleeds rarely last for long. From time to time, a bleed lingers long enough to leave an impression, and the memory of the merged planes lives on for anywhere from hours to centuries. Festering corruption is an example of one such memory, and it results when a part of the Shadowfell oozes into the natural world. Little can survive the dark plane’s touch. Affected areas feature dead grass underfoot, bones littering the ground, and skeletal trees whose clattering branches rattle with each gust. Only the most filth-hardened creatures can survive in these places for long.
Effect: An area of festering corruption is usually no larger than 4 squares on a side. Festering corruption has two effects, one for the living and one for the undead.
Whenever a living creature ends its turn in an area of festering corruption, it must make a saving throw. On a save, there is no effect. On a failed saving throw, the creature takes 5 necrotic damage per tier and is slowed until the end of its next turn.
Whenever an undead creature ends its turn in an area of festering corruption, it gains a +2 bonus to attack rolls and its speed until the end of its next turn.
Usage: Festering corruption results in places where someone or something has compromised the planar boundary’s integrity. Dark rituals, shadow magic, or the creation of powerful undead can all create pockets of festering corruption.
Published in The Book of Vile Darkness, page(s) 2-27.