**Part three of the [case study series][1].** [Part 1 - Tim B][2] [Part 2 - Daaaah Whoosh][3] ---- **I submit the following for review.** http://worldbuilding.stackexchange.com/questions/18414/what-single-element-could-destroy-the-world **About world building?** Insofar as destroying worlds is about world building yes, I believe this is on topic. My major gripe with this question was actually some of the answers it attracted. Many of the answers failed to take the premise of a mad scientist into account. This led to some modifications of the restrictions that I placed around the situation. I didn't feel that some of them should have been necessary but if you're not specific around here people tend to go for outlandish. **Risking off-topic?** No, this question seems pretty strait forward on topic to me. If anything you could probably claim it is idea generation but I think the restrictions put in place make it clear I am looking for someone with chemistry/physics knowledge to fill in the gaps. ---- http://worldbuilding.stackexchange.com/questions/9717/how-would-space-battles-alter-combat-tactics **About world building?** This question helps define combat in space, so in my mind is a discussion of how things differ from the combat we are used to today. Feels pretty on-topic, discussion of a system and how it impacts the world. **Risking off-topic?** Nope, I am happy this one is well within scope. ---- http://worldbuilding.stackexchange.com/questions/527/what-are-the-primary-triggers-for-the-degrading-and-fall-of-great-empires **About world building?** Yes this is about world building, specifically developing a history for the world in question. **Risking off-topic?** I think it is probably too broad. We went back and forth on this question several times. It was an early question on the site so I can't recall exactly, but I think it was closed once or twice. This question would probably have benefited from the sandbox but I don't think it had been created yet. It could probably be reworked to be more on topic, I'm just not sure how. ---- http://worldbuilding.stackexchange.com/questions/10102/how-would-multi-race-humanoid-evolution-happen **About world building?** Absolutely. **Risking off-topic?** Not at all. This one is nice and clean. ---- http://worldbuilding.stackexchange.com/questions/7301/how-to-explain-the-co-existence-of-peace-and-violence-in-religion **About world building?** Yes, the goal of this question was to help illuminate how this process works so it can be included in the world as a source of conflict throughout history etc. **Risking off-topic?** It feels on topic to me but there could be an argument that this is a plot idea. I think the question is effectively framed as looking at the system though so it should be good. [1]: http://meta.worldbuilding.stackexchange.com/questions/3048/case-study-series [2]: http://meta.worldbuilding.stackexchange.com/questions/3043/case-studies-on-or-off-topic [3]: http://meta.worldbuilding.stackexchange.com/questions/3063/case-study-2-daaaah-whoosh