• Everyone knows that the dangers, treasures, and secrets of the world trickle down into holes in the earth. If you want to find riches, look down. If you want to stay safe, never leave the sun or stars behind. Almost all of the danger and reward will take place underground. One more time: this game is about searching for treasure and magic beneath the earth.
• Every single player character is a foolish, desperate, or strangely driven person, who is involved in an extremely risky undertaking for the slim chance of some kind of profit. They are not mercenaries. No one will hire them to delve. They are adventurers, and they get themselves into trouble.
• The races do not mix much. Cities and nations are human phenomena.
• This particular stretch of country, and the earth beneath it, has only one language, so all creatures can understand each other if they have the mind to. Strangers from elsewhere find that all language is transparent, whether they want it to be or not.
• There is a guild of wizards, but it is not the only route to magical might. The greatest wizards often leave the academy – eventually. The mightiest magic will not work beneath the sun and the stars, and even the weakest magic is extremely uncommon. Magic is a careful study and mental discipline, rather than an inner power.
• There is no guild of thieves, unless a player character is enterprising enough to organize one.
• There is a well-organized church, whose single unimaginable creator god is aided by many, many saints. Some of these saints, such as Jesus, Mary, Buddha, Gruumsh, Thor, Loki, Coyote, Quetzalcoatl, St. George, St. Jude, Moradin, Shiva, or General Tso, seem to have stories with contradictory messages. But, as any archbishop will tell you, it is only a mortal church, no mysteries will be made plain in this life, and the dialectic of the small gods is part of the worship of the great god. Some clergy are devoted to a particular small god, but most are concerned with finding the right saint for the purpose at hand. Great cathedrals, remote monasteries, and humble chapels dot the land, and provide a great service to the people, not only guiding their souls, teaching difficult skills like reading, and organizing their labors, but often providing law and order when the feudal system of lords will not. Clerics are battle trained clergy. It is quite possible that they will adventure in search of a fortune with which to found an institution themselves. Some clergy, it is rumored, are devoted to the Secret Saints, or Rebellious Saints, or True Saints, like Orcus, Satan, Dracula, and Lolth. Most clergy love their ranks, rituals, and garments, though some spurn the trappings.