The tech tree in Civilization IV is very flexible, thanks to the addition of OR gates and the elimination of static eras. It’s now possible to reach certain technology by researching different techs. For example, you can get to Gunpowder by researching either Guilds or Education. There is also no longer a minimum number of turns needed to discover a technology, making it easier to come back and get older technologies that you haven’t researched yet. In addition, Great People can be used to help with research. Each great people type can usually research a certain type of techs. For example, a Great Prophet can help research a religion tech, while a Great Artist can help research a cultural tech.
NOTE: Information in this section is correct as of Beyond the Sword, version 3.17. Items in italics mean that other technologies are also required for construction.
| Icon | Technology | Cost | Requires | Leads To | Units Enabled | Buildings Enabled | Special Abilities |
|---|---|---|---|---|---|---|---|
 | Advanced Flight | 5000 | Satellites, Flight | Stealth | Gunship, Jet Fighter | Obsoletes Stables | |
 | Aesthetics | 300 | Writing | Literature, Drama | The Parthenon, Statue of Zeus, Shwedagon Paya | ||
 | Agriculture | 60 | Pottery, Animal Husbandry | Can build Farms | |||
 | Alphabet | 300 | Writing | Literature (with Polytheism), Drama | Spy | Enables tech trading Can build Research | |
 | Animal Husbandry | 100 | Agriculture or Hunting | Writing, Horseback Riding | Reveals Horse Can build Pastures | ||
 | Archery | 60 | Hunting | Archer, Skirmisher, Longbowman, Crossbowman, Cho-Ko-Nu, Horse Archer, Keshik, Camel Archer, Numidian Cavalry, Bowman | |||
 | Artillery | 4000 | Physics, Steel, & Rifling | Rocketry | Artillery, Anti-Tank, Mobile Artillery | ||
 | Assembly Line | 5000 | Corporation & Steam Power | Fascism (with Nationalism), Industrialism (with Electricity) | Infantry | Factory Coal Plant Shale Plant Pentagon | |
 | Astronomy | 2000 | Calendar & Optics | Scientific Method (with Printing Press), Physics (with Scientific Method) | Galleon, East Indiaman, Privateer, Frigate, Ship of the Line | Observatory, Salon | Obsoletes Colossus, Monument, Stonehenge Enables trade on Ocean |
 | Banking | 700 | Currency & Guilds | Economics (with Education), Replacement Parts (with Printing Press) | Bank, Stock Exchange | Enables Mercantilism | |
 | Biology | 3600 | Chemistry & Scientific Method | Medicine (with Optics), Ecology (with Plastic or Fission), Refrigeration (with Electricity) | National Park | Can build farms w/o irrigation Farm produces +1 food | |
 | Bronze Working | 120 | Mining | Iron Working, Metal Casting (with Pottery) | Axeman, Phalanx, Vulture, Dog Soldier, Holkan | Reveals Copper Enables Slavery Can chop down forests | |
 | Calendar | 350 | Sailing & Mathematics | Astronomy (with Optics) | Mausoleum of Maussollos | Can build Plantations Centers world map | |
 | Chemistry | 1800 | Engineering & Gunpowder | Scientific Method (with Printing Press), Biology (with Scientific Method), Steam Power (Replaceable Parts), Steel (with Iron Working) | Privateer, Frigate | Workshops +1 production | |
 | Civil Service | 800 | Code of Laws or Feudalism, Mathematics | Paper, Nationalism (with Divine Right or Philosophy) | Maceman, Samurai, Bezerker | Farms spread irrigation Enables Bureaucracy | |
 | Code of Laws | 350 | Writing & (Priesthood or Currency) | Civil Service, Philosophy (with Meditation), Constitution (with Nationalism) | Courthouse, Sacrificial Altar, Rathaus Chichen Itza | First to discover founds Confucianism. Enables Caste System | |
 | Combustion | 3600 | Railroad | Flight (with Physics), Plastics (with Industrialism) | Transport, Destroyer, Attack Submarine | Public Transportation, Creative Constructions | Can build oil wells. Obsoletes whale |
 | Communism | 2800 | Liberalism & Scientific Method | Spy | Intelligence Agency Kremlin | First to discovery receives Great Spy. Enables permanent alliances, Enables State Property | |
 | Compass | 400 | Sailing & Iron Working | Optics (with Machinery) | Explorer | Harbor, Cothon | |
 | Composites | 7500 | Plastics & Satellites | Future Tech (with Genetic) | Modern Armor | SS Casing | |
 | Computers | 6500 | Radio, Plastics | Genetics (with Refrigeration), Fiber Optics (with Plastics or Satellites), Robotics (with Plastics) | Modern Armor | The Internet | Obsoletes Angkor Wat, University of Sankore & Spiral Minaret |
 | Constitution | 2000 | Code of Laws & Nationalism | Democracy (with Printing Press), Corporation (with Economics) | Jail, Mausoleum | Enables Representation | |
 | Construction | 350 | Masonry & Mathematics | Engineering (with Machinery) | War Elephant, Ballista Elephant, Catapult, Hwacha | Colosseum, Odeon, Ball Court, Garden | Enables bridge building |
 | Corporation | 1600 | Constitution & Economics | Assembly Line (with Steam Power) | Wall Street, all corporations | Obsoletes Great Lighthouse +1 trade route per city | |
 | Currency | 400 | Mathematics or Alphabet | Code of Laws (with Writing), Banking (with Guilds) | Market, Forum, Grocer, Apothecary | Enables gold trading via diplomacy. +1 trade route per city Can build Wealth. | |
 | Democracy | 2800 | Constitution & Printing Press | Statue of Liberty, Security Bureau | Enables Universal Suffrage & Emancipation | ||
 | Divine Right | 1200 | Theology & Monarchy | Nationalism (with Civil Service) | Versailles Spiral Minaret | First to discover founds Islam | |
 | Drama | 300 | Aesthetics | Music (with Mathematics), Philosophy (with Meditation) | Theater, Pavilion, Hippodrome Globe Theater | Can adjust culture rate | |
 | Ecology | 5500 | Biology & (Plastics or Fission) | Recycling Center SS Life Support | Can scrub Fallout | ||
 | Economics | 1400 | Banking & Education | Corporation (with Constitution) | Customs House, Feitoria | First to discover receives a Great Merchant. Enables Free Market Obsoletes Castle | |
 | Education | 1800 | Paper | Liberalism (with Philosophy), Economics (with Banking), Gunpowder | University, Seowon Oxford University | ||
 | Electricity | 4500 | Physics | Fission, Industrialism (with Assembly Line), Refrigeration (with Biology), Radio | Bunker Bomb Shelter Broadway | Windmills: +1 commerce Watermills: +2 commerce | |
 | Engineering | 1000 | Machinery & Construction | Chemistry (with Gunpowder) | Pikeman, Landsknecht, Trebuchet | Castle, Citadel Notre Dame | +1 road movement |
 | Fascism | 2400 | Assembly Line & Nationalism | Paratrooper | Mount Rushmore | First to discovery receives Great General. Enables Police State Can negotiate permanent alliances | |
 | Feudalism | 700 | Writing & Monarchy | Civil Service, Guilds (with Machinery) | Longbowman | Enables Vassalage, Serfdom | |
 | Fiber Optics | 7500 | Computers or Laser | Fusion (with Fission) | SS Cockpit | Obsoletes Kremlin | |
 | Fishing | 40 | Sailing, Pottery (with The Wheel) | Work Boat | Can work water tiles Can create Fishing Boats | ||
 | Fission | 5500 | Electricity | Ecology (with Biology), Fusion (with Fiber Optics) | Tactical Nuke, ICBM | Nuclear Plant Manhattan Project | |
 | Flight | 5000 | Physics & Combustion | Rocketry (with Rifling) | Paratrooper, Carrier, Fighter, Bomber | Airport | |
 | Fusion | 8000 | Fission & Fiber Optics | SS Engine | First to discover receives a Great Engineer | ||
 | Future Tech | 10000 | Composites & Genetics | +1 health & +1 happy face in all cities | |||
 | Genetics | 7000 | Medicine, Superconductors | Future Tech (with Composites) | SS Stasis Chamber | +3 health in all cities | |
 | Guilds | 1000 | Feudalism & Machinery | Banking (with Currency), Gunpowder | Knight, Camel Archer, Cataphract | Grocer, Apothecary | Workshop: +1 Hammer |
 | Gunpowder | 1200 | Guilds or Education | Chemistry (with Engineering), Rifling (with Replaceable Parts) | Musketman, Musketeer, Janissary, Oromo Warrior, Conquistador, Cuirassier | Enables Pinch | |
 | Horseback Riding | 250 | Animal Husbandry | Horse Archer, Keshik, Numidian Cavalry, Cataphract, Knight, Camel Archer, Conquistador, Cavalry, Cossack, War Elephant, Ballista Elephant | Stable, Ger | ||
 | Hunting | 40 | Archery, Animal Husbandry | Scout, Spearman, Phalanx, Impi | Can build Camps | ||
 | Industrialism | 6500 | Electricity & Assembly Line | Plastics (with Combustion) | Marine, Navy SEAL, Tank, Panzer, Battleship | Industrial Park | Reveals Aluminum Obsoletes Ivory |
 | Iron Working | 200 | Bronze Working | Compass (with Sailing), Steel (with Chemistry) | Swordsman, Jaguar, Gallic Warrior, Praetorian | Reveals Iron Can remove Jungle | |
 | Laser | 7000 | Plastics, Satellites | Mobile SAM, Mobile Artillery | SDI | ||
 | Liberalism | 1400 | Philosophy & Education | Communism (with Scientific Method) | First to discover receives a free tech. Enables Free Speech & Free Religion | ||
 | Literature | 200 | Polytheism & Aesthetics | Music (with Mathematics) | Heroic Epic National Epic Great Library | ||
 | Machinery | 700 | Metal Casting | Guilds (with Feudalism), Printing Press (with Paper), Engineering (with Construction), Optics (with Compass) | Crossbowman, Cho-Ko-Nu, Maceman, Samurai, Beserker | Can build windmill & watermill | |
 | Masonry | 80 | Mining or Mysticism | Monotheism (with Polytheism), Construction (with Mathematics) | City Walls, Dun, Aqueduct, Hammam, Baray Pyramids Great Wall Great Lighthouse | Can build quarry | |
 | Mass Media | 3600 | Radio | Broadcast Tower Hollywood United Nations Civilized Jewelers | Obsoletes Apostolic Palace | ||
 | Mathematics | 250 | Writing | Music (with Literature or Drama), Calendar (with Sailing), Construction (with Masonry), Currency | Aqueduct, Hammam, Baray Hanging Gardens | Can build fort. Workers produces 50% more hammers from chopping | |
 | Medicine | 4500 | Optics & Biology | Hospital Red Cross Sid’s Sushi Co. | Enables Environmentalism | ||
 | Meditation | 80 | Mysticism | Priesthood, Philosophy (with Code of Laws or Drama) | Monastery | First to discover founds Buddhism | |
 | Metal Casting | 450 | Pottery & Bronze Working | Machinery | Trireme | Forge, Mint, Colossus | Can build workshop |
 | Military Science | 2000 | Chemistry | Grenadier, Ship of the Line | Military Academy | Enables Blitz, Commando | |
 | Military Tradition | 2000 | Music & Nationalism | Conquistador, Cavalry, Cuirassier, Cossack | West Point | Enables defensive pacts | |
 | Mining | 50 | Masonry, Bronze Working | Can build mines | |||
 | Monarchy | 300 | Priesthood or Monotheism | Feudalism (with Writing), Divine Right (with Theology) | Enables Hereditary Rule Can build wineries | ||
 | Monotheism | 120 | Masonry & Polytheism | Theology (with Writing), Monarchy | Enables Organized Religion First to discover founds Judaism | ||
 | Music | 600 | Mathematics & (Literature or Drama) | Military Tradition (with Nationalism) | Cathedral Sistine Chapel | First to discover receives a Great Artist Can build Culture | |
 | Mysticism | 50 | Meditation, Polytheism, Masonry | Monument, Stele, Totem Pole, Obelisk Stonehenge | |||
 | Nationalism | 1800 | Civil Service & (Philosophy or Divine Right) | Military Tradition (with Music), Constitution (with Code of Laws), Fascism (with Assembly Line) | Hermitage Taj Mahal | Enables Nationhood | |
 | Optics | 600 | Compass & Machinery | Astronomy (with Calendar), Medicine (with Biology) | Caravel, Carrack | +1 sight across water Can create whaling boats | |
 | Paper | 600 | Theology or Civil Service | Education, Printing Press (with Machinery) | University of Sankore | Enables map trading | |
 | Philosophy | 800 | Meditation & (Drama or Code of Laws) | Nationalism (with Civil Service), Liberalism (with Education) | Angkor Wat | First to discover founds Taoism Enables Pacifism | |
 | Physics | 4000 | Astronomy & Scientific Method | Electricity, Flight (with Combustion), Artillery (with Steel and Rifling) | Airship | Reveals Uranium First to discover receives a Great Scientist | |
 | Plastics | 7000 | Combustion & Industrialism | Ecology (with Biology), Composites (with Satellites), Fiber Optics (with Computers), Robotics (with Computers) | Hydro Plant Three Gorges Dam Standard Ethanol | Obsoletes fur Can create Offshore Platform | |
 | Polytheism | 100 | Mysticism | Priesthood, Monotheism (with Masonry), Literature (with Alphabet) | Parthenon, Temple of Artemis | First to discover founds Hinduism | |
 | Pottery | 80 | The Wheel & (Agriculture or Fishing) | Writing, Metal Casting (with Bronze Working) | Granary, Terrace | Can build cottages | |
 | Priesthood | 60 | Meditation or Polytheism | Monarchy, Code of Laws (with Writing), Writing | Temple Oracle | ||
 | Printing Press | 1600 | Machinery, Alphabet & Paper | Democracy (with Constitution), Scientific Method (with Chemistry or Astronomy), Replaceable Parts (with Banking) | Villages & towns produce +1 commerce | ||
 | Radio | 6000 | Electricity | Mass Media, Computers, Satellites (with Rocketry) | Submarine, Attack Submarine, Bomber, Guided Missile | Eiffel Tower Rock N Roll Cristo Redentor | |
 | Railroad | 4500 | Steam Power & Steel | Combustion | Machine Gun | Mining Inc. | Can build railroads |
 | Refrigeration | 4000 | Biology & Electricity | Genetics (with Computers) | Supermarket, Mall Cereal Mills | +1 extra move for water units | |
 | Replaceable Parts | 1800 | Banking & Printing Press | Rifling (with Gunpowder), Steam Power (with Chemistry) | Can build lumbermills. Windmills & watermills +1 hammer | ||
 | Rifling | 2400 | Gunpowder & Replaceable Parts | Artillery (with Physics, Steel), Rocketry (with Flight or Artillery) | Rifleman, Redcoat, Infantry, Marine, Navy SEAL, Paratrooper, Mech. Infantry, Tank, Panzer, Cavalry, Cossack | Obsoletes Walls, Chichen Itza | |
 | Robotics | 8000 | Computers | Missile Cruiser, Stealth Destroyer, Mech. Infantry, Stealth Bomber | Space Elevator | ||
 | Rocketry | 5000 | Rifling & (Flight or Artillery) | Satellites (with Radio) | SAM Infantry, Attack Submarine, Guided Missile, Tactical Nuke, ICBM | Aluminum Co. Apollo Program | |
 | Sailing | 100 | Fishing | Calendar (with Mathematics), Compass (with Iron Working) | Galley, Trireme | Lighthouse, Trading Post, Great Lighthouse, Moai Statues | Enables trade on coast, rivers |
 | Satellites | 6000 | Radio & Rocketry | Composites (with Plastics), Fiber Optics (with Computers) | SS Docking Bay Space Elevator | Reveals world map | |
 | Scientific Method | 2400 | Printing Press & (Chemistry or Astronomy) | Communism (with Liberalism), Physics (Astronomy), Biology (with Chemistry) | Reveals Oil Obsoletes Great Library, Parthenon & Monastery Can build forest preserves | ||
 | Stealth | 8000 | Composites, Advanced Flight | Stealth Destroyer, Stealth Bomber | |||
 | Steam Power | 3200 | Chemistry & Replaceable Parts | Assembly Line (with Corporation), Railroad (with Steel) | Ironclad | Levee, Dike | Reveals Coal Workers build improvements +50% faster Obsoletes Hagia Sophia |
 | Steel | 2800 | Iron Working & Chemistry | Railroad (with Steam Power), Artillery (with Physics and Rifling) | Cannon, Ironclad | Drydock Ironworks | |
 | Superconductors | 6500 | Refrigeration or Computers | Genetics | Laboratory, Research Institute, SS Thrusters | ||
 | Theology | 500 | Writing & Monotheism | Divine Right (with Monarchy), Paper | Hagia Sophia, Apostolic Palace | First to discover founds Christianity Enables Theocracy | |
 | The Wheel | 60 | Pottery (with Agriculture or Fishing) | Chariot, War Chariot, Immortal | Can build roads | ||
 | Writing | 120 | Priesthood or Animal Husbandry or Pottery | Code of Laws (with Priesthood or Currency), Feudalism (with Monarchy), Theology (with Monotheism), Mathematics, Alphabet | Library, Madrassa | Enables Open Borders |
Related Links:
- The full Civ4 in-game tech tree
- More info about technologies are available in the Civilization IV Info Center.