Mir - A long way...
Farming, herding, and basic craft has been the your life, and the life of most people you know. The Lords, the majestic Yuan-Ti, offer protection from the wilds in exchange for your labor and love. It is a system that has worked for many decades, perhaps even centuries. Between basic survival and labor, there is little time for learning. Except for a very few, dangerously curious folk. Books are a secret one must keep close, for every village has a Justicar.
Sometimes on hunts, you have witnessed the ruins of a temple. You can see the stone statues of fallen gods, and broken holy symbols. There is no meaning attached to these, besides a feeling of power that seems to be writhing under a damp, heavy blanket.
In game terms, any Arcane spellcaster who relies on a spellbook will be severely limited on character creation. A wizard may only know one spell, and a magus may not know any. Sorcerer bloodlines are found at an early age and tracked, usually with a tutor provided from the gracious Yuan-Ti. Witches graciously fall off the radar, though a stigma is usually attached to such craft (which could be good or bad).
Holy spellcasters are hunted down as heretics. Most were burned alive during the cleansing long ago. Most temples lay in ruin, with very few holy symbols left intact. With such little tutelage available, some spells may be unavailable to clerics and paladins. Oracles are seen much as witches, with a strange stigma.
With the lack of divine focus, alignment is much more fluid and with much less emphasis placed. It still may factor into things, and will be a guiding principle, but will be much less restrictive (in this environment at least).
Optional rules used (we can discuss, but these are initial thoughts): we will be using armor as DR, and also wound points. Armor as DR is as it sounds, where each character has a defensive stat which is based on dex and level (to avoid attacks), and DR to absorb it. Wound points: characters gain HP as normal per level, but also have wound points. These are derived from your CON score. When your normal HP gone, you take wound point damage (and also through other means, such as crit hits). When you have wound damage, you are very limited in the number of things you can do in a round. These rules are found in ultimate combat for anyone interested.
More to come!