> > As a matter of fact, I do play Crusader Kings II. And after playing it for hours on end, I'd say I have a pretty good understanding of how the game works.
> 
> I want to know how the administration within the country is set? Like, a kingdom is separated into smaller duchies which are then separated into counties, etc.? 

I've just realized that the game ends after 1337, exactly 63 before the start of this RP in 1400. So we won't be able to use Crusader Kings II for information without sacrificing historical accuracy. However, if you're willing to forgive the inaccuracy, here's the administration according to Crusader Kings II, starting from the largest and ending with the smallest:

Empire

Kingdom

Duchy

County

Bishopric/Barony/City (They've been put together like this because they all only exist within a county.)