“ In a deeply unsettled world, much of it anarchistic or ruled by murderous gangs, a group have adopted the armour, weapons and discipline of an army of the distant past.”
“ There exists a prestigious academy with a history going back hundreds of years. Graduates are highly skilled and very much sought after for employment. For purely traditional reasons, the academy requires its students to become proficient in a skill or area of knowledge that has no use in the modern world. This could be Ancient Egyptian, an antiquated form of writing such as shorthand, knowledge of building or repairing antique steam engines, programming COBOL, etc. PCs who graduated from this academy must be sure to have this skill in their repertoire.”
“ While it is within your purview to write long-spanning histories of your world, it is largely unnecessary. If you are running an RPG, do this instead: make a bullet point list of important events that affect the world today, and mysteries that people still don't know. Let these fuel your adventures.”