Limits on fort building

[thedoctorking]

How is it that some units in non-urban terrain can get up to level 3 forts (Level 3 plus 10%), while others are restricted to level 2? What are the restrictions on fortification? Is this another reason to build fortified zones?

[No idea]

If you are in plain or light forest terrain AND next to a fort unit the fort level can get up to three, iirc. So yes. There is some incentive to build fort zones on the countryside

[Joneleth]

ORIGINAL: thedoctorking

How is it that some units in non-urban terrain can get up to level 3 forts (Level 3 plus 10%), while others are restricted to level 2? What are the restrictions on fortification? Is this another reason to build fortified zones?

39. Changed fort construction rules. Fort level 5 can be built only in cities with large port
containing a fort unit. Fort level 4 can be built only in big cities (city, light urban or heavy
urban terrain) or towns with port containing a fort unit. Fort level 3 can be built only in big
cities, towns with port, in hexes with a fort unit or adjacent to an enemy. Fort level 2 can
be built only next to a fort unit, in coastal zones or up to 3 hexes from a supplied enemy
unit. Fort level 1 can be built only up to 20 hexes from a supplied enemy unit. In swamp
terrain the fort cannot be larger than 2

[tomeck48]

So why are ports so special? Seems like a city is a city is a city. Is it a question of resources or a question of strategic imperative?

[Joneleth]

ORIGINAL: tomeck48

So why are ports so special? Seems like a city is a city is a city. Is it a question of resources or a question of strategic imperative?

I think its due to possible navy support, both as artillery support from warships but also from refitting gun turrets from ships as fortification points as was done in leningrad.