This is a homebrew setting that I’ve had floating around in my head for the past 25+ years or so. I have some specifics outlined and others not quite so fleshed out.
Known differences are:
Any arcane spellcaster’s eyes will glow based upon the highest spell level they can cast, using the visual light spectrum (ROYGBIV). This means arcane spellcasters that can only cast lvl 1 spells will have Violet glowing eyes while those that have access to lvl 9 spells will have red glowing eyes.
Arcane spellcasters that do not cast their spells innately/spontaneously are subject to a saving throw vs their own spell. This is because prepared magic is actually not the intended way for arcane magics to be made manifest within the world. This save is made repeatedly until it fails for a given day. This is to represent the stress upon the body and the result of improper use of arcane magic. Once the save is failed the spellcaster acquires an amount of Corruption. Corruption is a disease in the world that occured during it’s original reconstruction; this was something that the gods missed and there is no known solution that mortal man knows of to remove this disease in the world.
Aborial Hobgoblins are not true hobgoblins. This was a name given to them ages ago. This particular race is on par in strength with the Imperium.
The pantheon is organic and can incorporate any number of beliefs. If it’s not listed it can be added.
Magic items are generally more rare than in most games, at least in the beginning. This is the age of an ancient culture that you could find in any other world. That so called ‘ancient and forgotten culture of high magic’ is what this world will become by campaign end.
The story moves on with or without player interaction.
Players are encouraged to take the reigns on where the adventure goes.
This was originally written mostly from a 2nd Edition D&D viewpoint with some 3rd Edition 3.0 alterations before the system was ‘fixed’. To be truthful, this world is best run using a 1st or 2nd Edition D&D system. Later versions make the characters more powerful than the world can handle so there will be adjustments.