As Jediwarlock puts it in their video on World of Warcraft :

…There are so many directions I could take to explain why Classic is a masterpiece but while writing this video I always found myself coming back to one thing first and foremost: the world. That might seem obvious or maybe a cop out - I mean it’s literally in the title of the game - but it’s such a critical part of what made early WoW so iconic, so atmospheric, and I’m sure like many of you that feeling has drawn you in from day one. The variety and uniqueness of each zone plays a major role and there’s rarely a case where the environment seems repetitive or dull. There is obvious passion and dedication on display by the developers from the very beginning, and even with some reused assets from time to time every zone has its own essence, story, and opportunities to explore something new…

Regions are areas of the map with a distinctive environment that sets them apart from other regions, and have designated themes, mobs, and scenery. These areas have borders much like a state or country, and though sometimes invisible, they define areas. They may contain subregions, towns, or dungeons.

At the same time, subregions should be visually unique in the context of each region. This may prove challenging, but I want each screenshot of the future game to be tied geographically to a specific subregion. Like, you could pinpoint where exactly in the world you are just by looking at your surroundings, if you have played long enough. But subregions design will come much later in my worldbuilding process.

Apart from unique environments, each region should also have both internal and external tension. External, or world tensions will be developed much later, after exploring each region. But internal tensions, like faction disputes, will be developed from the start in each region separately. Each region will have its cast of Factions and Agents. Later, when developing external tensions, I might go back and revise inconsistencies in the internal tensions as well as plots intertwine and merge.

Given my goals to turn this into both a TTRPG setting and a playable RPG game, each region should have:

  • A Status Quo that the region starts with
  • A series of Factions or Agents with specific Agendas the players can interact with