The banshee or groaning spirit, is the spirit of an evil female elf—a very rare thing indeed. Banshee hate the living, finding their presence painful, and seek to harm whomever they meet.
Banshees appear as floating, luminous phantasms of their former selves. Their image glows brightly at night, but is transparent in sunlight (60% invisible). Most banshees are old and withered, but a few (10%) who died young retain their former beauty. The hair of a groaning spirit is wild and unkempt. Her dress is usually tattered rags. Her face is a mask of pain and anguish, but hatred and ire burns brightly in her eyes. Banshees frequently cry out in pain—hence their name.
Banshees are formidable opponents. The mere sight of one causes fear, unless a successful saving throw vs. spell is rolled. Those who fail must flee in terror for 10 rounds and are 50% likely to drop any items they were carrying in their hands.
A banshee's most dreaded weapon is its wail or keen. Any creature within 30 feet of a groaning spirit when she keens must roll a saving throw vs. death magic. Those who fail die immediately, their faces contorted in horror. Fortunately, groaning spirits can keen just once per day, and then only at night. The touch of a groaning spirit causes 1d8 points of damage.
Banshees are noncorporeal and invulnerable to weapons of less than +1 enchantment. In addition, groaning spirits are highly resistant to magic (50%). They are fully immune to charm, sleep, and hold spells and to cold- and electricity-based attacks. Holy water causes 2d4 points of damage if broken upon them. A dispel evil spell will kill a groaning spirit. A banshee is turned as a "special" undead.
Banshees can sense the presence of living creatures up to five miles away. Any creature that remains within five miles of a groaning spirit lair is sure to be attacked when night falls. The nature of this attack varies with the victim. Beasts and less threatening characters are killed via a touch. Adventurers or demihumans are attacked by keening. Creatures powerful enough to withstand the groaning spirit's keen are left alone.
When attacking adventurers, the groaning spirit attacks at night with her wail. If any characters save successfully, she then retreats to her lair. Thereafter, each night, the groaning spirit returns to wail again. This routine is repeated until all of the victims are dead or have left the groaning spirit's domain, or until the groaning spirit is slain.
Banshees loathe all living things and thus make their homes in desolate countryside or ancient ruins. There they hide by day, when they cannot keen, and wander the surrounding countryside by night. The land encircling a groaning spirit's lair is strewn with the bones of beasts who heard the groaning spirit's cry. Once a groaning spirit establishes her lair she will remain there.
The treasure of groaning spirits varies considerably and often reflects what they loved in life. Many hoard gold and fine gems. Other groaning spirits, particularly those that haunt their former homes, show finer tastes, preserving great works of art and sculptures, or powerful magical items.
It is nearly impossible to distinguish the cry of a groaning spirit from that of a human or elf woman in pain. Many a knight gallant has mistaken the two sounds, and then paid for the mistake with his life. Banshees are exceptionally intelligent and speak numerous languages, including common, elvish, and other demihuman languages.
Banshees occasionally use their destructive powers to seek revenge against their former adversaries in life.
Banshees are a blight wherever they settle. They kill without discretion, and their only pleasure is the misfortune and misery of others. In addition to slaying both man and beast, a groaning spirit's keen has a powerful effect upon vegetation. Flowers and delicate plants wither and die and trees grow twisted and sickly, while hardier plants, thistles and the like, flourish. After a few years all that remains within five miles of a groaning spirit's lair is a desolate wilderness of warped trees and thorns mixed with the bones of those creatures that dared to cross into the groaning spirit's domain.