Setting
The eternal war between the Black God and White God rages. The mortals still fight, but their strife has been called to peace. Through prophets of both gods and heavy losses in the last war, the people are unwilling to slay one another and retain the blessings of their God by ritual rather than bloodshed. Sacrifices have been made, and quite literally so, but the mortals have made their peace. Now is a time of exploration for the Mortal Realm- only a small part of their world is inhabited, due to the Cataclysmic Gray, a great reckoning where the Aether and the Mortal Realm collided and the war of the gods was fought on both fronts- until only those truly devout were left on the earth, clustered together in the last city. There, the Gods came to their first uneasy truce, allowing the Mortals to live.
The world has finally opened to the Mortals, and once more Aelus's golden streets and lofty spires are populated with the followers of both Gods. From here and from the many close-by border towns, great expansions are launched. Some take boats and sail for the open seas, some take great airships and fly above the clouds, and some take off on foot or by horse to find what there is to find out on the land. And find people did- sprawling ruins and dungeons now inhabited by all kinds of creatures unseen by the Mortals, many still holding treasure, and a time of wealth came to those willing to hunt for it...
You are one such mortal. Growing up as a member of one of the Twelve Houses, you picked up values and abilities that come in handy for the trials ahead. You and other various people you know- people you wouldn't go without- have made plans to become one of the many Adventuring Parties that seek to explore the world and blaze trails to places not yet seen- become successful enough, and it's possible you'll even be able to found your own outpost- then growing to a city under your guide. But before such dreams can be realized, the world must be uncovered from the veil it's under.
Heads up. I don't ever intent to run this. It's possible, maybe plausible, that something might come of it in the future, but it won't be this exact thing. Take from it what you will.
You are born under a House, each with a Sign of it's own. Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. Each House specializes in one area of theology- writing, prayer, summoning, and the like. For instance, Libra specializes in those who write the scriptures of the White God, and can record knowledge and words of the White God and preach them. Words of God are powerful and not to be trifled with- the Names of the Gods can cause events equal to the Cataclysmic Gray...
Basically, there are six abilities for each God, and the chosen sign gives a boost to one.
Furthermore, Role is an important factor in how you are seen. Although religion is unified, there are many different denominations for each group, as such:
The Followers are the simplest group of followers, they simply observe holiday of their religion and take a day of every week to hear their God's scripture read. They get no bonuses or penalties.
The Spectre are a group of followers who cover themselves from head to toe in cloth matching the color of their God, and devoutly read and preach the Words of their God. They are able to read and write the Aether language, translate it, and read it. Unfortunately, to learn the Language and become a Spectre, they go through a ritual that deafens them permanently.
(Others later, maybe a total of four)
Past that, I don't know. The idea is, there's a great and ever-expanding dungeon list, you travel to them, and you fight things and solve the dungeon. You earn money and the like to a goal- such as a ship or Airship, to further your travels. Magic is replaced with Words of God and other similar God-power abilities, and Mana is replaced with Favor. Favor increases as you make sacrifices, pray, or wait (as supposedly those people at home are doing things to please the God) and the abilities most-of-the-time drain it. Also, two d20s are rolled every turn, a White Die and a Black Die. If the numbers are low, some abilities can't be used, if they are high, powerful abilities can be used.