Do I have any fans of Final Fantasy reading this? How about Dragon Quest or Star Ocean? Or any RPG that involved encounters with monsters in the environment? Those games played a key role in the development of Tariatla, the world Eric finds himself in at the start of his Journey to Chaos. I wanted to create a world that was similar to the games I'd played growing up. In keeping with the idea of "Tariatla as a real world" I thought about how such a world would cope with monsters in everyday life.
"Well," I thought, "there would be a lot of walls". So I looked up cities in medieval Europe and ancient China and other places for how they built walls. What they were made of and how they were maintained and defended; the details for keeping a city safe.
Then such a society would need someone to fight the monsters. They would need soldiers employed by the local government and professional warriors hired by private citizens. In other words, the world would need mercenaries and their newest one came from another world. In college, I took a class about medieval European warfare and my professor spent the bulk of it talking about logistics: food, equipment, payment, soldiers and their organization etc. Naturally Eric and his team would have to take care of this and I think it adds a layer to the constructed world. It can make one more understanding of a mercenary's insistence on getting paid; it worked for me.
Finally the society would need a mindset that included the 'monsters outside the walls'. There would be those stayed in the city to avoid them, those that liked to fight them and those that held the same opinion of monsters that real life people would have of mosquitoes: annoying and possibly dangerous, but a fact of life.
If you want to read more about this world, its monsters and its mercenaries, you can browse the Tvtropes page here: http://tvtropes.org/pmwiki/pmwiki.php/Literature/JourneyToChaos
Journey to Chaos, Book 1: A Mage's Power, is available at Amazon: http://smile.amazon.com/A-Mages-Power-Journey-Chaos-ebook/dp/B00AVMAISG