The tech tree Techs (short for "technologies") are empire upgrades that cost science and provide various benefits and make additional techs and some laws and events available.
Tier 1 (80 Science)
Technology
Prerequisites
Effects
Ironworking
None
Stonecutting
None
Trapping
None
Divination
None
Administration
None
Tier 2 (120 Science)
Technology
Prerequisites
Effects
Labor Force
Ironworking
Husbandry
Ironworking
Drama
Stonecutting
Polis
Stonecutting, Trapping
Military Drill
Trapping
Aristocracy
Divination
Rhetoric
Administration
Tier 3 (200 Science)
Technology
Prerequisites
Effects
Navigation
Labor Force
Phalanx
Labor Force
Spoked Wheel
Husbandry
Forestry
Polis
Steel
Military Drill, Ironworking
Sovereignty
Aristocracy, Rhetoric
Metaphysics
Rhetoric
Tier 4 (400 Science)
Technology
Prerequisites
Effects
Coinage
Navigation
Citizenship
Phalanx
Portcullis
Drama
Land Consolidation
Forestry
Composite Bow
Rhetoric
Monasticism
Aristocracy
Machinery
Sovereignty
Tier 5 (600 Science)
Technology
Prerequisites
Effects
Scholarship
Citizenship
Stirrups
Spoked Wheel, Citizenship
Architecture
Portcullis
Manor
Land Consolidation, Composite Bow
Battleline
Steel, Phalanax
Doctrine
Monasticism
Torsion
Machinery
Cartography
Metaphysics, Navigation
Tier 6 (800 Science)
Technology
Prerequisites
Effects
Hydraulics
Coinage
Jurisprudence
Scholarship
Martial Code
Stirrups
Vaulting
Architecture
Bodkin Arrow
Manor
Cohorts
Battleline
Windlass
Torsion
Tier 7 (1000 Science)
Technology
Prerequisites
Effects
Lateen Sail
Hydraulics
Fiscal Policy
Jurisprudence
Barding
Steel, Martial Code
Infantry Square
Bodkin Arrow
Chain Drive
Windlass
Ballistics
Cartography
Tier 8 (1200 Science)
Technology
Prerequisites
Effects
Economic Reform
Lateen Sail, Fiscal Policy
Military Prestige
Barding, Infantry Square
Industrial Progress
Chain Drive, Ballistics
