Tribes Advance
Tribes can Advance through the Eras
(Even though many technologies does not work for them, there is no reason they should not be able to make horse shoes)
Tribes have access to other forms of Partition Succession
(Needs required Innovation and higher Tribal Authority)
Innovation for Partition moved to Tribal Era
Innovation for High Partition moved to Early Medieval Era
Absolute Tribal Authority disables inter-warring vassals
Tribals can create Cadet Branches
Tribes can build new tribal holdings in their province, now called Tribal Forts
If they have researched all fortification technologies, they can construct a castle as their tier 2 Tribal Hold upgrade
(uses Castle graphics) (this will make them viable late game, but is expensive to build and no tier 2 until 1200- should hinder them mid game)
Tribes have less initial levies, but are better defensively
Tribes can build some Duchy holdings (Archery Grounds, Blacksmiths, Siege Works and Jousting Fields)
Note: I did not find a way to limit Gathering Hall building to one per province, please let me know if you know how to do this, as I do not think it is immersive to have the Chieftains Halls in every county. And if I could limit it the AI can only build Palisades, War Camp and Markets, since counties only have 3 holding slots, which would be great.
