“When you build your campaign you will tailor it to suit your personal tastes. In the heat of play it will slowly evolve into a compound of your personality and those of your better participants, a superior alloy.” – DMG 7
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Work in progress.
A core part of old-school D&D is the DIY spirit, and that includes developing your own milieu for your game over the course of a long period of time. D&D shines in the long-term, ongoing campaign, backed by a game system that supports such play (for instance, AD&D). By planting your milieu's seeds, you prepare the fields for the cities, mountains, armies, dungeons, and dragons that will appear there over the course of time. Your seeds need not be more than a single settlement, a single dungeon, and a pantheon of modest size. From there, if you do it right, you will find that the world writes itself.
Early on, you will need to be able to have information on:
Later on, you will want to have information on: