NOTE: This is something I had submitted to WotC during their open submission window for Dragon. They took a pass on it. But that is cool, because it means I can expand it and pass it on now to you for free.
From the Ancient Dragon Scrolls, #54:
Selûne was created from the primordial essence of the universe, along with her twin sister, Shar. Together, they created Chauntea (the embodiment of the world of Abeir-Toril) and some other heavenly bodies and infused these areas with life. The two goddesses then fought over the fate of their creations. From these struggles emerged the original deities of magic, war, disease, murder, death, and others. Selûne reached out of the universe and from a plane of fire, brought forth a flame and ignited a heavenly body in order to give warmth to Chauntea. This greatly enraged Shar, and she began to erase all light and warmth in the universe. Desperate and weakened because of Shar's actions, Selûne hurled some of her divine essence at her sister. Selûne's essence tore through Shar, bringing some of Shar's essence with it. This magical energy combined to form the goddess Mystryl, the original goddess of magic."So says the legends of the Realms. Selûne and Shar, sisters locked in eternal battle, eternal struggle. But this is not the observations of a few; the chosen to know the truth. It is true that siblings fight, they argue, yet do they also not love each other still? Are they not more alike than different?
These were the first questions asked by the first of our order, the truths they lead to though would make us shunned by both the Light and the Dark. Shunned, because deep down they know their own teachings are only half-truths their litanies incomplete. Shunned because we know the terrible, wonderful truth that the Goddesses of the moon, Sehanine, Selûne and Shar, are in truth aspects of the One Triple Goddess."
Followers of the Triple Goddess, known amongst themselves as the Sisterhood of the Triple Goddess (aka Sisters) believe that the Goddess always has been, it is mortals that have artificially split Her into component Goddesses because they can not comprehend Her in Her true form. She is Sehanine, Selûne and Shar individually and all at once. There is no contradiction. Followers of the individual Goddesses fight among themselves because their doctrines are so close to each other, yet they only have a small piece of the truer picture.
Each Aspect is much as the Goddess she represents; Sehanine is the ever youthful Maiden, Selûne the powerful Mother and Shar, the most misunderstood but still shrouded in shadow, decay and death.
The Maiden. In Her guise as Sehanine Moonbow, the Maiden is ever young. She is represents new beginnings, youth and re-birth. It is the Maiden that represents the freedom of youth but also growth. She is most often seen in lush green vegetation, the eternal Spring, the Waxing Crescent Moon. For this reason she is also most often associated with the elves and the Feywild. She is young, capricious and fickle as befits Her nature. She dallies with Gods (and sometimes Goddesses) to sow the next generations. When she does she becomes the Mother.
The Mother. In Her Aspect as the Mother, She is most often worshiped under the name Selûne. Here She is the Goddess of the Summer, the Full Moon. She is associated with the Prime Material and the practical. She is the Mother. Strong, proud, and stern if needed, but loving and understanding. Since the Spellplauge She is depicted as being full with child. Some say she is pregnant with the reborn Mystra and it is through the Mother that Magic enters the world.
The Crone. The most misunderstood of all the Aspects of the Goddess. Though to be evil She is demonized as Shar, the Dark Moon. The Crone is far, far more than that. True, She is responsible for death, darkness and decay, but these are natural processes of Life, Death and Rebirth. She is the Crone of Winter and all souls pass by Her. Forgive her if She seems bitter or cold, She only knows of Death. For this She is most often associated with the Shadowfell. She honors the followers of Shar, but does not understand their fascination with death. Death is needed so that others may live and grow. The harvest must be sown, the fields must be cleared, sometimes burned, so that new seeds and growth can occur. The Crone knows much, but the price of Her wisdom is high.
The Worshippers of The Triple Goddess
The lay worshipper of the Triple Goddess is typically female (thus the name Sisterhood), as the Goddess waxes and wanes in course with the moon, so does a woman as she progresses in life as Maiden, Mother and Crone and through only monthly cycle.
Tenets of Faith
The Triple Goddess is worshiped by anyone that worships one of her Aspects, but Her faithful know the truth.
• She is the Moon, waxing and wanning as the Moon does
• She brings Light, Life and Darkness to the World.
• She is the Goddess of Rebirth, Life and Death. Therefore her true believers can never use, or have used on them, any Raise Dead Spell; only Reincarnation.
• Share the word of the Triple Goddess, but do not attempt to convert others. They will come into the fold when they are ready.
• Do what you can to help followers of the Goddess' Aspects.
• Destroy undead. They are an abomination to the Rebirth, Life, Death cycle and therefore an affront to the Goddess.
Relations between the Worshipers.
The Sister of the Triple Goddess share many of the same practices of faith as do the followers of Sehanine, Selûne and Shar. In fact it is not uncommon that a follower of the Triple Goddess will be part of one of the other members' sects. She (and the followers are most often a she rather than a he) will quietly perform her duties next to her unsuspecting sisters, all the while knowing that only she knows the whole truth.
If discovered the follower is usually asked to renounce their heretical beliefs, other service or punishments may be required depending on the sect she belongs too.
The followers of Sehanine view the Triple Goddess as an interesting curiosity. They are more than willing to assume that Sehanine and Selûne could be the same and of course there are still many among the elves that believe that Sehanine is part of a Trinity with Hanali Celanil and Aerdrie Faenya, so this is not a stretch for them. Sisters are usually only asked to maintain pleasant relations with the rest of Sehanine's followers.
The Sisters see the followers of Sehanine as sweet, but hopelessly naïve. This they see as a consequence of only following the Maiden Aspect of the Goddess. They lack the experiences and wisdom that would come to them from learning from the Mother and Crone.
There is much similarity between the Elven Goddess Angharradh and the Triple Goddess. Cheif among these are Sehanine and their similar symbols. Sisters see Angharradh as a separate Elven Goddess more representative of the deep-seated desire in the elves to reunite their race. Unlike Angharradh, who is both the same as and seperate from her aspects, the Sisters believe that The Triple Goddess is One and Three as the same time. There is no separating Sehanine from the Goddess.
The Selûnites see the Sisters as also being naïve, but not about the true nature of their Goddess, but instead underestimating the evil and influence of Shar. Some of the more Orthodox members even see the Sisters as a threat set up by Shar Herself to undermine them from within; something they refer to as the Heresy of the Dark Moon (in which they completely ignore Sehanine). It is not the Triunity or even Trinity they have the issues with, it is the fact they include Shar in it.
Though it is speculated that there are Sisters in some of the highest ranks of the Selûnite church.
The Sisters see the Selûnites as being blinded by their hatred of "Shar" to see the full reality; there is no "Shar" as a separate Goddess. Shar, The Crone is necessary for life to continue and grow.
Swords of the Lady: The "Lunatics" appreciate The Sister's stance on undead, but feel their belief that Shar is part of their Goddess to heresy in the extreme. The Sister's see the Swords as dangerous fanatics.
Oracles of the Moon: The Oracles and the Sisters actually get along quite well. The Oracles tend to see more than the other followers and the Sisters find the Oracles very knowledgeble, but removed from worldly concerns.
Silverstars: Silverstars are wary of the Sisters, feeling like the Swords, that cleave a little too closely to Shar for their liking. However individually they do tend to get along since Sisters value life above all else. The Sisters admire the Silverstars and feel their cause is worthy and just. They just wished they could find the way to seeing the full Goddess.
The Followers of Shar tend to be a dark, evil lot. They view the Sisters as cowards for not embracing true evil and watering down their belief with the likes of Sehanine and Selûne. They have nothing but contempt for them. Punishments can include forced re-conversion by torture. When the Sisters were first discovered within the ranks of the Sharites they were captured and infected with Werewolf Lycanthropy. What shocked and surprised both sides were that the Sisters so infected retained their own minds when transformed; something even the Selûnites could not do.
The Sisters see the Sharites as perverters of the Goddesses true form. Yes, the Crone is shadowy and surrounded by death, but it is the ultimate destination for us all. To focus on that aspect alone is perverse. The Sisters run the greatest personal risk from the Sharites, but they are also the ones the Sisters feel the need to reach out to the most.
Dark Justicars: The Justicars consider the Sisters to be dangerous heretics and usually kill them on sight. The Sisters avoid the Justicars at all costs. Some souls can't be saved.
Order of the Dark Moon: More accepting of the Sisters since their own tappings into the Dark Weave has lead them to believe that is of the same nature as the Weave. If this is true, then the teachings of the Sisters, as radical as they are, could also be true. The Sisters find the Order to be very austere in their thinking and are not surprised that their single minded dedication to the Shadow Weave also blinds them to the greater being of the Triple Goddess. They are not to be taken lightly, but represent the best inroad into Shar's cult they have.
Nightcloaks/Nightbringers: The Orthodoxy of the Church of Shar see the Sisters as a threat and one that must be destroyed. The Sisters view the Nightcloaks as the true poison in Shar's worship. If this dangerous element can be removed the Sisters feel the rest of the followers of Shar will become followers of the Triple Goddess.
As an unaligned deity the Tripple Goddess is misunderstood by the clergy and lay member of most of the other faiths. The followers of Chantea in her form of the Great Mother have much in common with the Sisters. While the dogman and tenets of faith are very, very similar, there are enough differences to keep them from being close.
Centers of Worship
The Sisters are found everywhere that the worshipers of Sehanine, Selûne and Shar. In particular they are located in the Moonshae Isles. There are centers of worship in Waterdeep as well.
The Triple Goddess is the Unaligned Goddess of the Moon, Magic and Change.
Type: Greater God
Symbol: Three interlocking circles
Domain: Arcana, Change, Moon
Special: Worshipers may take any feat or Paragon Path that is limited to Sehanine, Selûne and Shar, with alignment considerations.
The Triple Goddess find worshipers among all sorts of peoples. She is predominantly worshiped by Witches, Celestial Sorcerers, Fey and Dark Pact Warlocks, Moon Elves and Half-Elves. She is also worshipped by good or unaligned Half-Orcs. Regardless of race or class Her faithful are mostly women. Those that devote themselves to destroying Undead will also pay Her homage, especially if they hunt at night.
The worship of The Triple Goddess is strongest anywhere where the Prime Material, Shadowfell and the Feywild overlap. There is known activity in Winterhaven.
Third Edition D&D
The Triple Goddess
Goddess of the Moon, Change, Magic and Mysteries
Symbol: Three interlocking circles
Home Plane: The Moon
Alignment: Lawful Neutral
Portfolio: Moon, Magic, Night, Mysteries
Worshipers: Women, witches, Astrologers,
Cleric Alignment: Any
Domains: Arcana, Change, Moon
Favored Weapon: None (magic)
The world is more complex than you know and there are still great mysteries. The Triple Goddess is the keeper of these mysteries, but to understand them you must first understand Her.