A single prop that does not look real to an audience can louse you up. The same is true of the smallest flaw in setting up the motivation in a story line. ~ Desi Arnaz
A Guide begins by building the story world, or setting, around the Adventurers.
The fourth core area a Guide must address and when creating a new role-play setting:
What technology or magic is commonplace?
Create the Personal Equipment, Vehicles, and Structures.
An Adventurer's understanding should touch on what a person living within the setting would know as “common knowledge” and from a basic education within these core parts of the setting.
Each Adventurer could only have a subset of the common information of the setting based on their particular background.
What is the common knowledge about technology or magic in this world?