- Supply dump => Supply depot (can be upgraded to form forts or villages
- Village=> Town => City => Megapolis
- Temple (req level 1 food, level 1 medicine)
- Fort => Castle => Fortress => Redoubt Complex (req level 1 metallurgy, level 1 supply)
- Sentry post => Tower => Keep => Bastion => Bunker (req level 1 timber, level 1 construction)
- Smithy => Foundry => Smelter - required to build Fort (req level 2 science)
- Storage pit => Granary - required to build Temple (req level 2 science)
- Stockyard => Timberyard => Sawmill - required to build towers, outposts, and the like (req level 2 science)
- University => handles knowledge accumulation and knowledge research
- Hovel => Drill Square => Barracks
- Warrior Hall => Nobles' Court => War Academy
- Steelworks => Steel mill - produces steel from timber and metal, very resource-intensive unless you have plenty of coal spots.
- Pier => Dockyard => Shipyard
- Workshop => Factory => Assembly Plant
- Engineering Depot (required for all heavy modern weapons)
- Airstrip => Air base
- Archives => Library
- Monument (buildable only in a city, as long as you control marble. Each monument reduces dissent in a city)
- Brothel => Tavern => Coffee House => Arcades reduces dissent
- earthworks => stone walls => fortified walls - climbable walls which function a bit like cliffs. China has a monopoly on these. Towers can be built incorporating these structures.
Can only be built in Early Classical Era, and requires some experience. Knowledge however is dangerous and often results in unhappiness whenever it is researched. Ratio of unhappiness is Knowledge tech level / Average religious level of all players + 1, rounded up
- Education - requires Late Classical Era from Library
- Humanist thought - requires Middle Ages, and Science 3: Astrology and Horology from Library
- Empiricism - requires Colonial Era, Science 5: Natural History from Library
- Academic disciplines - requires Enlightenment,
- Scientific method - requires Mechanisation Era, Science 7: Combustion from Library
- Internet - requires Digital Era, Civics 7: Intergovernmental Initiative and Science:9 Quantum Mechanics from Library
Increases food production. Reseaerched from Storage Pit.
- Plough - requires Bronze Age
- Irrigation - requires Late Classical, Architecture
- Crop rotation - requires Colonial Era
- Fertilisers - requires Mechanisation, Replaceable Parts
- Environmentalism - requires Information Era, Scientific Method. Double gather effects from merchant rares too.
Allows units to heal faster if garrisoned, and also increases unit creation rate and unit recharge rate. Researched from Storage Pit.
- Pharmacopeia - requires Bronze Age
- Anatomy - requires Renaissance, and Humanist Thought
- Microbiology - requires Electronics and Academic Disciplines
- Universal healthcare - requires Atomic Era, Scientific Method
- Forestry - requires Agriculture
- Coppicing - requires Medieval Era
- Paper industry - requires Early Industrial Era,
- Polymers - requires Electronic Era
Stockyard reseearch. Improves build speed and HP.
- Division of Labour
- Architecture - req Humanist Thought, Guilds
- Engineering - req Empiricism, Assembly Line
- Replaceable Parts - req Scientific method, Electronic Era
- Coking process - Medieval, Alchemy (4)
- Steel - Colonial, Natural History
- Bessemer Process - Engineering, Scientific Method, Late Industrial
Increases resistance to attrition. Improves build rate and repair of ships, then mech units.
- Forage - req Middle Ages
- Supply - req Colonial, Division of Labour
- Railway Networks - req Scientific Method, Architecture
- Logistics - req Replaceable Parts, Electronic Era