As you can see from even a brief perusal of the previous post, the term "post-apocalyptic" covers a lot of ground. Therefore, before you begin designing your campaign world, it's helpful to stop for a moment and ponder what exactly it is you mean to include. And what you intend to leave out. In essence, you need to ask yourself the following questions:
- Is this game going to be set in real-world earth, a future-earth, a past-earth, an alternative universe earth or another world altogether?
- What was the "Event" that triggered the destruction the world?
- What was the technology base pre-Event?
- How long ago was the Event?
- How far has civilisation recovered?
- Who (and what) what Survived? Does your world have a place for Aliens? Mutants? Zombies? Robots? Supernatural Creatures? Psionic Powers? Magic? Scientific Enclaves? Do any Pre-Event power blocs or agencies survive?
- What is the specific role of the characters in this world? If any?
- Finally, given what you know about your world setting, what rules system would be best to use?
Here's how I used these questions to establish my own post-apocalyptic setting: