Some 'mundane' things I also generally add to my campaign worlds as 'fluff':
- famous battles that everyone knows, often the showcase of some specific strategy
- famous generals
- famous bards / travellers who documented large parts of the world
- special greeting customs for certain area's and/or specific social classes
- certain 'taboo's', such as only the emperor is allowed to dress in yellow, only nobles are allowed to own gold coins etc.
I usually also develop histories for relatively mundane magical items. i.e. it is just a sword +2, but it has a handle shaped like a dragon and the mark of the order of Blah, so it must have been the sword of the last grandmaster of that order, or it is a 'standard' staff of the magi but it is shaped like an elongated female. This was the staff of the Mad Arch Mage and the form is actually the women he loved but betrayed him, cursed to form the staff...
Stuff like that...
I would add to this list:
-Famous Knowledgable Persons: be it a sage, a mage, a prolific cloistered priest/adept. Someone known/acknowledged as the foremost authority on X (within the academic circle of whatever the subject matter is).
In developing my world of Orea, I created (somewhat by accident) a well known (long dead) sage who did extensive research and study (and writings) of the world's races. So 1) in explaining the races there are excerpts from Belbin's treatise on XYZ. 2)There is a name that knowledgable/educated types (wizards, clerics, bards, etc.) would be recognized and trusted on certain subjects. 3) It may spark something in the players/PCs when finding libraries and such "Hey, are any of these books written by Soandso the Sage?"
-Famous Heroes/Adventuring Companies...and their contributions to the world/society.
In my world, the last truly "world famous" adventuring company incorporated the greatest bard of the last age. His followers established the foremost bardic college/training center of minstrels in the world.
The ranger of that group is credited with establishing the current organization of rangers of the northern kingdom. The fighter-type became the first high-king of that realm (sorta an Arthurian figure). The mage became the world's first "Dragonmage" (mortal wielder of draconic magic) since long forgotten ages.
The priestess/cleric was actually "Sainted" by her goddess, creating a new branch of the religion and ascended to demi-goddess-hood worshiped in conjunction with the greater goddess.
Make the commonly known "heroes of legend"
truly legendary! They contribute to the geo-political make up, the world's mythology, the world's history (this particular group defeated the demon-demigod who was
thiiiis close to taking over the world) etc. EVERYone (or just about) has heard a song or story around the fire involving these guys n' gals.
This kind of common knowledge not only adds flavor to the world's past (possibly
recent past), but also provides "inspiration" for the players as something to aspire to.
It provides a reason why they (and others) continue to seek fame and fortune in the "adventurer" lifestyle...cuz someone in the past attained REAL fame and/or fortune...It
is possible to reach "greatness"!
-SD