The number of creatures that receive worship is staggering, but if that isn’t confusing enough, many of the beings have multiple Aspects, each of which is held holy by different cults. Many times the same god is worshipped by different cults under entirely different names, often without the realization of the cults involved.
The origins of most of the gods are equally murky, and often mutually contradictory. One god may be considered the son of another by one cult, but another cult of the same god may not acknowledge the existence of the father in any way – or believe in a different father. Since the worship itself determines the god, all of the cults are correct, even those that hold mutually exclusive tenets.
Shattered gods
The Shattered gods are the most powerful deities of Erth. Each embodies the Primal Force of a prime alignment. There are thousands of gods that share an alignment with a Shattered god, but all worship to that alignment contributes to the existence and power of the related Shattered god whether this is intentional or not. There is one Shattered god each for Good, Evil, Law, Chaos, Neutrality, Neutral Good, Lawful Good, Chaotic Good, Lawful Neutral, Chaotic Neutral, Lawful Evil, Chaotic Evil, and Neutral Evil.
All of the Shattered gods have cults on Erth, but it is exceptionally difficult for mortals to achieve the purity and dedication to an alignment that is required to worship a Shattered god directly. More commonly, the cults of Shattered gods are populated with semi-supernatural, or otherwise non-mortal beings and even constructs that are more easily capable of the single-minded devotion required by the deity. This is especially true of the “Pure” Primal Forces of Good, Evil, Law, Chaos and Neutrality: it is almost unheard of for a Human or other race of Man to be found in one of these cults. Shattered gods each have only one Domain: their alignment.
Lesser gods
The term “Lesser” is misleading. Most of the Lesser gods are extremely powerful, often the heads of major pantheons. These beings were created during the Godswar by the Shattered gods. This was not always on purpose, and there are many Lesser gods who ended up opposing their creator. Many of the Shattered gods also have Aspects that are themselves Lesser gods, for instance Baccalon is the Shattered god of neutral evil and also has an Aspect as the Lesser god Baccalon the Hooked Man.
Most of the largest and most powerful cults and sects on Erth worship Lesser gods. Lesser gods often have more than one Domain, but none have their alignment as a Domain.
New gods
Man (including all the races of Man) is the creator of the New gods. They were each ideas that, for whatever reason, gained worship and worshippers. Many were saints or unusually powerful and famous (or infamous) Men that gained a following and ascended into deity-hood.
There are more New gods than can be counted. Many of their cults also worship one or more Lesser gods and see the New god as a minor member of the pantheon. There are New god cults that believe their god is truly a Shattered god, or even more unusual, the only god, and since they worship in that manner, to them it becomes true. New gods tend to be specialists, arising from one idea into godhood, and therefore generally have only one Domain. As with the Lesser gods, no New god has an alignment as a Domain.
Erth deities
This is an incomplete listing of some of the gods unique to Erth. One note, the name Mephistopheles later turned up in a source book (Monster Manual 2) but the Erth version has nothing in common with the published version.
Dunamis Powerhurler, Aspect of power and law (L/G but worshippers may be any Lawful) there are several other Aspects of Dunamis (Icebringer, Peacemaker) but this is the most popular. Only Mudmen worship him directly with no aspect.
Almora the White Sensitive, bittersweet goddess of love and love's anguish (C/G but worshippers may be any in love or who have felt the pain of love)
Baccalon the Hooked Man, Aspect of evil (N/E worshippers must be N/E). Baccalon is also the N/E Shattered god but PCs are not eligible to worship him directly
Denethor god of joyful battle (C/N but worshippers may be any as long as they are also warrior)
Faresta goddess of revelry (N/G but worshippers may be any - except Erin who is required to be N/G) cult is tightly aligned with Lobar and Mar-Boro
Lobar god of adventure and comedy (N/G worshippers may be any Good) see Faresta
Mar-Boro god of intellect (L/N worshippers must be L/N) see Faresta
Mephistopheles father of demons (C/E worshippers must be C/E) this god was killed during Godswar but somehow remains very popular among the crueler races of Man
Roland Giantslay, patron of warriors (L/G worshippers must be any Good) Lots of war gods on Erth
Santara, ruler of the dead (N/E, worshippers may be any Evil) Constantly scheming to add all of Erth to her underworld domain (often with the help of Baccalon). Her cult is banned in your area.
Stachia Erth Mother goddess of the Erth and nature (N, worshippers can be any Neutral but must all be female). Her priestesses have spells and abilities that wax and wane with the seasons
Stralos the infinite, god of the sky (C/N worshippers must be C/N). A distant god that remains mostly uninvolved with Man but is most popular among avians.
The Archon Protector of Humanity (L/G worshippers may be any Human)
The Darkon (L/E worshippers may be any Human) Tirelessly works for the domination of all by Humanity. His cult is banned in your area.
The Vaatch god of dream and reality (true neutral worshippers may be any) A completely different god, separate from any pantheon, that may or may not actually exist. Has no organized cult but does have isolated worshippers.
Choosing a deity
Only characters with Divine spells are required to choose a patron deity. All others may choose to be non-religious if they wish.
All of the deities found in all of the D&D and AD&D sourcebooks are eligible to be selected. So pick anyone you want from any world. There are exceptions, but in general, a deity listed in a sourcebook as a greater god (or greater devil or demon) translates to Erth as a Lesser god, and all others are New gods
No Erth god except the Shattered gods may have a Domain in the following: Law, Chaos, Evil, Good, Neutrality. If the removal of one of these domains will cripple your deity of choice, I will come up with another substitute domain.
No Erth god may ever under any circumstances appear in the Primal Plane. Instead, they send Avatars. Your various sourcebooks that describe the abilities and appearances of a deity are all actually describing the being's preferred Avatar.
Most cults provide a special ability to their devout worshippers (the cult ability), and most also expect certain actions to show continued devotion (the cult sacrifice). Failure to follow the rules of the sacrifice results in (at the least) loss of the ability until atonement is made
I have a huge list of gods from various sourcebooks, and have given them all Domains (if they did not have them already) special abilities and mode of sacrifice. I prefer that players choose their deity, if any, based on the deity, and not the ability or sacrifice so I am not posting my huge list. Plus it is huge. Did I mention how large it is?
If it turns that you select a deity who’s ability or sacrifice is incompatible with your character (in your opinion, not mine). I’ll suggest someone similar who may work better for you
If you have no idea at all what deity to choose but want to have one, give me some idea however vague of what you might want and I’ll try to play holy matchmaker for you.