Jaynus - I love this whole concept, and I might be able to provide coding/xml support once things lighten up here at work... But I have a few more Ideas- Terrain Improvement- Superhighways Prereq tech - Combustion + Plastics Effects - Unlimited Movement (ALA old railroads) +2 Commerce -1 Health High Upkeep cost Cost- Must Build on top of RR, twice as expensive Reason- Many people forget this, but the original justification of the Modern US interstate highway system was military- While in the military, Eisenhower was charged with moving a few divisions across the country- this took him almost nine months on the 'organic' highways system that existed at the time- something he considered a travestry- thus he pushed the Eisenhower interstate system through... Superhighways are very expensive (to both build an maintain), but they highly boost nation's commerce and allow instantious travel of military units between all connected squares. City Improvements- Railroad Yard Prereq tech - Industrialization + Railroad Effects- -1 Health A city with a rail yard can choose to 'support' the production of another city with a rail yard, adding 50% of its production to the target city. (Perhap boosted to 75% once computers come around) Reason- Once rail came around- nations no longer had to complete entire projects in one city... case in point - the construction of liberty ships in WWII was actually done far inland, and the completed sections of the liberty ships were then shipped by rail to the coasts where they were assembled in as little as 42 hours, stem to stern. There should be something similar in Civ. Passenger Terminal PreReqs- Plastics City already has airport Effects- -1 Health City commerce boosted 25% high upkeep Reason- Airports have a tremendous effect on a nations commerce, this should be modeled. Minor Wonder (1 Per Civ)- Passenger Hub Prereqs- 5 Passenger Terminals Effect- Boosts Commerce in Target City 100% All airports boost commerce 50% (vs 25% without). Ideally, passenger terminals should produce barely more commerce than their upkeep costs initially, but once a Hub is in place, the commerce Boost becomes far more substantial.