Looking through the Deryni Adventure Game again since I last posted about it has reminded me of a few things. For one thing, the game, like the novels it's based on, uses real-world medieval European religion - meaning Christianity - as the dominant religion. Judaism, Islam and Paganism are briefly mentioned as well, but they are not the focus of either the novels or the game. It has a pretty good depiction of the various social classes and roles within its society, and lots of background on day-to-day life, from food, to justice, to the arts. It's pretty damn comprehensive, without overwhelming amounts of lore (though, make no mistake, there is lore). It would be very easy to use TDAG to run a more historical game (ignore the psychic/magical Deryni and change the country names back to their obvious inspirations boom done). Or, if you're looking for a low-magic medieval setting, you can just run it as-is. In-game, only the Deryni have psychic/magical abilities, but there is nothing mechanically stopping you from extending that to all humans, or some, as desired. TDAG uses the FUDGE system, though there are some brief notes for converting it to D20.Bottom line: TDAG is a strongly medieval European flavored RPG that closely adheres to the novels it sprang from.