Tribal Holdings
Tribal holdings (though I don't know if that will be their actual in game names) sound like they will be much like castles, bishoprics and cities, although Doomdark also put trade posts in that list, which leads me to believe they might be an over-holding of some sort (to prevent the awkwardness of having one holding change to another later in the game). Essentially tribal holdings will represent lands that aren't properly fortified yet, more owned by virtue of people living there than by people actually building towns etc.
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Elective Gavelkind
Another interesting new feature, designed for the breaking up of blobs: elective gavelkind. Empires being too blobby has always been a big concern, and even more so with the introduction of a start date that may very well include the entirety of Francia as one huge empire. At least one response to this, which also adds to the susceptibility of tribal civilisations falling apart without a leader, is elective gavelkind.
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Vassal Limit
A new limit, much like the current demesne limit, will be imposed upon rulers with the introduction of the Charlemagne DLC. This limit does exactly what it suggests: it imposes a soft-cap on the number of independent vassals you can have in your realm before you start taking penalties. To offset this, you will be encouraged to hand out more duchy titles, and perhaps even kingdoms, as your empire becomes too large for you to manage each vassal yourself.
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