A new feature for a supply line should be added to the game. Supply IN: In it provinces will have to move there production back to the capital through supply lines moving through friendly territory or seas. Each province will have a transfer value on how much resources it could pass on to another territory. Seas and cities will have infinite transfer value. Transfer Value can be increased using Infrastructure. If a resource cant be reached because of low transfer value the resource gain will be wasted. This will be shown in the resource production menu as 'Resources Disrupted:'. If a place is encircled with enemy territory it cant give out or take in supply lines. Supply lines may be passed through a diplomatic status called 'Supply Access'.
Supply Out: Supply out lines will go from the capital to the units according to consumption value. If a unit doesn't get its consumption resources it will lose damage value. If in the middle of supply lines are enemy units the supply will be destroyed according to the units 'Supply Damage' value. Thus naval blockades will be much more efficient if the Player has overseas colonies, whoes supply in and out line will be disrupted.
Supply Out: Supply out lines will go from the capital to the units according to consumption value. If a unit doesn't get its consumption resources it will lose damage value. If in the middle of supply lines are enemy units the supply will be destroyed according to the units 'Supply Damage' value. Thus naval blockades will be much more efficient if the Player has overseas colonies, whoes supply in and out line will be disrupted.