Design Approach
Source GM Core pg. 138
World building can be approached in many ways, but it fundamentally comes down to a simple preference. Do you start at a high level and zoom in, or do you start small and build up? This section outlines a largely top-down approach, but you can design from the bottom up simply by starting at the end of this section and working backward. Either way, you might find yourself skipping between sections as inspiration strikes—and that's OK!
When building worlds, there's a risk of becoming overwhelmed by the sheer number of decisions to be made. Remember that you don't need to make every decision for every aspect of your world all at once. Focus first on the elements you need for your story and the game, then add as much of the rest as you'd like. You'll also want to allow room for input from your players—gaming sessions are more memorable and engaging when the storytelling experience is shared between everyone at the table (Narrative Collaboration has more information on players contributing to the narrative).
Before you decide anything else, however, you should establish your concept and your goals. Do you envision a bustling port of call in Near Space? A star system where magic comes from quarreling regional deities who each control a separate warring planetoid? A low-tech moon unknowingly isolated from the rest of a high-tech system full of starships? Are you designing a whole region of space for a multi-year campaign, or a single settlement on a world for a fast-paced one-shot adventure? Having an idea in mind will help steer your choices as you build your worlds, and knowing your goals will help you focus on building what you need.
When building worlds, there's a risk of becoming overwhelmed by the sheer number of decisions to be made. Remember that you don't need to make every decision for every aspect of your world all at once. Focus first on the elements you need for your story and the game, then add as much of the rest as you'd like. You'll also want to allow room for input from your players—gaming sessions are more memorable and engaging when the storytelling experience is shared between everyone at the table (Narrative Collaboration has more information on players contributing to the narrative).
Before you decide anything else, however, you should establish your concept and your goals. Do you envision a bustling port of call in Near Space? A star system where magic comes from quarreling regional deities who each control a separate warring planetoid? A low-tech moon unknowingly isolated from the rest of a high-tech system full of starships? Are you designing a whole region of space for a multi-year campaign, or a single settlement on a world for a fast-paced one-shot adventure? Having an idea in mind will help steer your choices as you build your worlds, and knowing your goals will help you focus on building what you need.
Top Down
Source GM Core pg. 138
The top-down approach is great if you have a lot of time to dedicate to world building. When designing a setting from the top down, your initial focus is on the big picture. You might already have an idea of the big movers and shakers of your world or your multiverse. You might want to chronicle a thousand years or more of the setting's history. You might have already sketched out a galactic map with each planet's continents, nations, and factions spanning these worlds. This approach begins with broad generalities that get more detailed during play and as you design them.
Bottom Up
Source GM Core pg. 138
With a bottom-up approach to world building, you start small and local. Focus on the starting location and immediate needs of your campaign, then expand outward as the story unfolds. This strategy works well for those with less time to devote to world building, as you need to prepare only the minimum detail necessary to entice your players toward adventure, fleshing out your world only as the campaign requires it.