C I V I L I Z A T I O N A D V A N C E S Cross Reference <- = prerequisites, listed in reverse chronological order -> = successors, listed in forward chronological order ADVANCES -------- Alphabet -> Writing, MapMaking, Code of Laws, Mathematics, Diplomat, Library, Trireme, Lighthouse, Courthouse, Literacy, Monarchy, Trade, Catapult, Astronomy, Great Library, Republic, Philosophy, Feudalism, Caravan, Copernicus, Navigation, Banking, Medicine, Religion, Democracy, University, Chivalry, Invention, Sail, Magellan, Physics, Bank, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Knight, Gunpowder, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Musketeer, Metallurgy, Frigate, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Bronze Working -> Iron Working, Currency, Legion, Marketplace, Trade, Construction, Caravan, Aqueduct, Colosseum, Fortress, Engineering, Bridge Building, Banking, Medicine, Invention, Bank, Shakespeare, Chemistry, Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Ceremonial Burial -> Temple, Mysticism, Monarchy, Oracle, Astronomy, Philosophy, Feudalism, Copernicus, Navigation, Medicine, Religion, Democracy, University, Chivalry, Sail, Magellan, Physics, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Knight, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Metallurgy, Frigate, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Masonry -> Palace, City Wall, Pyramids, Great Wall, Mathematics, Construction, Catapult, Astronomy, Feudalism, Aqueduct, Colosseum, Fortress, Engineering, Bridge Building, Copernicus, Navigation, University, Chivalry, Invention, Sail, Magellan, Physics, Chemistry, University (Imp), Theory of Gravity, Knight, Gunpowder, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Musketeer, Metallurgy, Frigate, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module The Wheel -> Chariot, Engineering, Invention, Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Horseback Riding -> Cavalry, Chivalry, Knight Pottery -> Granary, Hanging Garden Map Making -> Navigation, Sail, Magellan, Physics, Magnetism, Steam Engine, Atomic Theory, Frigate, Railroad, Ironclad, Electricity, Darwin's Voyage, Industrialization, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Writing <- Alphabet -> Diplomat, Library, Literacy, Great Library, Republic, Philosophy, Banking, Medicine, Religion, Democracy, University, Invention, Bank, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Gunpowder, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module MapMaking <- Alphabet -> Trireme, Lighthouse Code of Laws <- Alphabet -> Courthouse, Literacy, Monarchy, Trade, Great Library, Republic, Philosophy, Feudalism, Caravan, Banking, Medicine, Religion, Democracy, University, Chivalry, Invention, Bank, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Knight, Gunpowder, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Iron Working <- Bronze Working -> Legion, Bridge Building, Gunpowder, Explosives, Musketeer, Metallurgy, Railroad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Currency <- Bronze Working -> Marketplace, Trade, Construction, Caravan, Aqueduct, Colosseum, Fortress, Engineering, Bridge Building, Banking, Medicine, Invention, Bank, Shakespeare, Chemistry, Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Mysticism <- Ceremonial Burial -> Oracle, Astronomy, Philosophy, Copernicus, Navigation, Medicine, Religion, Democracy, University, Sail, Magellan, Physics, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Metallurgy, Frigate, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Mathematics <- Masonry, Alphabet -> Catapult, Astronomy, Copernicus, Navigation, University, Sail, Magellan, Physics, Chemistry, University (Imp), Theory of Gravity, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Metallurgy, Frigate, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Literacy <- Code of Laws, Writing, Alphabet -> Great Library, Republic, Philosophy, Banking, Medicine, Religion, Democracy, University, Invention, Bank, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Gunpowder, Steam Engine, Isaac Newton, Atomic Theory, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Monarchy <- Code of Laws, Ceremonial Burial, Alphabet -> Feudalism, Chivalry, Knight Trade <- Currency, Code of Laws, Bronze Working, Alphabet -> Caravan, Banking, Medicine, Bank, Shakespeare, Chemistry, Explosives, Conscription, Industrialization, Rifleman, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Construction <- Currency, Masonry, Bronze Working -> Aqueduct, Colosseum, Fortress, Engineering, Bridge Building, Invention, Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Astronomy <- Mathematics, Mysticism, Masonry, Ceremonial Burial, Alphabet -> Copernicus, Navigation, Sail, Magellan, Physics, Theory of Gravity, Magnetism, Steam Engine, Isaac Newton, Atomic Theory, Frigate, Railroad, Ironclad, Electricity, Darwin's Voyage, Industrialization, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Republic <- Literacy, Code of Laws, Writing, Alphabet -> Banking, Bank, Conscription, Industrialization, Rifleman, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Philosophy <- Literacy, Mysticism, Code of Laws, Writing, Ceremonial Burial, Alphabet -> Medicine, Religion, Democracy, University, Shakespeare, Cathedral, J.S. Bach, Michelangelo, Chemistry, University (Imp), Theory of Gravity, Isaac Newton, Atomic Theory, Explosives, Metallurgy, Conscription, Cannon, Electricity, Rifleman, Electronics, Steel, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Feudalism <- Monarchy, Code of Laws, Masonry, Ceremonial Burial, Alphabet -> Chivalry, Knight Engineering <- Construction, Currency, The Wheel, Masonry, Bronze Working -> Invention, Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Bridge Building <- Construction, Currency, Iron Working, Masonry, Bronze Working -> Railroad, Darwin's Voyage, Industrialization, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Navigation <- Astronomy, Mathematics, Mysticism, Map Making, Masonry, Ceremonial Burial, Alphabet -> Sail, Magellan, Physics, Magnetism, Steam Engine, Atomic Theory, Frigate, Railroad, Ironclad, Electricity, Darwin's Voyage, Industrialization, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Banking <- Republic, Trade, Literacy, Currency, Code of Laws, Writing, Bronze Working, Alphabet -> Bank, Industrialization, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Medicine <- Philosophy, Trade, Literacy, Mysticism, Currency, Code of Laws, Writing, Ceremonial Burial, Bronze Working, Alphabet -> Shakespeare, Chemistry, Explosives, Conscription, Rifleman, Refining, Genetic Eng., Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Religion <- Philosophy, Literacy, Mysticism, Code of Laws, Writing, Ceremonial Burial, Alphabet -> Cathedral, J.S. Bach, Michelangelo Democracy <- Philosophy, Literacy, Mysticism, Code of Laws, Writing, Ceremonial Burial, Alphabet -> Recycling, Recycling Center University <- Philosophy, Literacy, Mathematics, Mysticism, Code of Laws, Writing, Masonry, Ceremonial Burial, Alphabet -> Chemistry, University (Imp), Theory of Gravity, Isaac Newton, Atomic Theory, Explosives, Metallurgy, Conscription, Cannon, Electricity, Rifleman, Electronics, Steel, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, SETI Program, Power Plant, Combustion, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Chivalry <- Feudalism, Monarchy, Code of Laws, Horseback Riding, Masonry, Ceremonial Burial, Alphabet -> Knight Invention <- Engineering, Construction, Literacy, Currency, Code of Laws, Writing, The Wheel, Masonry, Bronze Working, Alphabet -> Gunpowder, Steam Engine, Explosives, Musketeer, Metallurgy, Railroad, Ironclad, Conscription, Cannon, Electricity, Darwin's Voyage, Industrialization, Rifleman, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Physics <- Navigation, Astronomy, Mathematics, Mysticism, Map Making, Masonry, Ceremonial Burial, Alphabet -> Magnetism, Steam Engine, Atomic Theory, Frigate, Railroad, Ironclad, Electricity, Darwin's Voyage, Industrialization, Electronics, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Hydro Plant, Hoover Dam, Computers, Battleship, Refining, Genetic Eng., United Nations, SETI Program, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Chemistry <- University, Medicine, Philosophy, Trade, Literacy, Mathematics, Mysticism, Currency, Code of Laws, Writing, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Explosives, Conscription, Rifleman, Refining, Power Plant, Combustion, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Theory of Gravity <- University, Philosophy, Astronomy, Literacy, Mathematics, Mysticism, Code of Laws, Writing, Masonry, Ceremonial Burial, Alphabet -> Isaac Newton, Atomic Theory, Nuclear Fission, Manhattan Project, Nuclear Power, Nuclear Plant, Fusion Power Gunpowder <- Invention, Engineering, Construction, Literacy, Currency, Iron Working, Code of Laws, Writing, The Wheel, Masonry, Bronze Working, Alphabet -> Explosives, Musketeer, Metallurgy, Conscription, Cannon, Electricity, Rifleman, Electronics, Steel, Hydro Plant, Hoover Dam, Computers, Battleship, SETI Program, Combustion, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Magnetism <- Physics, Navigation, Astronomy, Mathematics, Mysticism, Map Making, Masonry, Ceremonial Burial, Alphabet -> Frigate, Electricity, Electronics, Hydro Plant, Hoover Dam, Computers, SETI Program, Advanced Flight, Bomber, Carrier, Rocketry, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Steam Engine <- Physics, Invention, Navigation, Engineering, Astronomy, Construction, Literacy, Mathematics, Mysticism, Currency, Code of Laws, Writing, Map Making, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Railroad, Ironclad, Darwin's Voyage, Industrialization, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Atomic Theory <- Theory of Gravity, Physics, University, Navigation, Philosophy, Astronomy, Literacy, Mathematics, Mysticism, Code of Laws, Writing, Map Making, Masonry, Ceremonial Burial, Alphabet -> Nuclear Fission, Manhattan Project, Nuclear Power, Nuclear Plant, Fusion Power Explosives <- Gunpowder, Chemistry, Invention, University, Medicine, Engineering, Philosophy, Construction, Trade, Literacy, Mathematics, Mysticism, Currency, Iron Working, Code of Laws, Writing, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Conscription, Rifleman, Combustion, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Metallurgy <- Gunpowder, Invention, University, Engineering, Philosophy, Construction, Literacy, Mathematics, Mysticism, Currency, Iron Working, Code of Laws, Writing, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Cannon, Electricity, Electronics, Steel, Hydro Plant, Hoover Dam, Computers, Battleship, SETI Program, Automobile, Armor, Mass Production, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Railroad <- Steam Engine, Physics, Invention, Navigation, Bridge Building, Engineering, Astronomy, Construction, Literacy, Mathematics, Mysticism, Currency, Iron Working, Code of Laws, Writing, Map Making, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Darwin's Voyage, Industrialization, Transport, Factory, Women's Suffrage, Steel, Corporation, Communism, Battleship, Refining, Genetic Eng., United Nations, Power Plant, Combustion, Cure for Cancer, Automobile, Cruiser, Flight, Armor, Mass Production, Fighter, Advanced Flight, Labor Union, Submarine, Mass Transit, Recycling, Nuclear Fission, Bomber, Carrier, Rocketry, Mech Infantry, Recycling Center, Manhattan Project, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Conscription <- Explosives, Gunpowder, Chemistry, Invention, University, Medicine, Engineering, Philosophy, Republic, Construction, Trade, Literacy, Mathematics, Mysticism, Currency, Iron Working, Code of Laws, Writing, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Rifleman Electricity <- Metallurgy, Magnetism, Gunpowder, Physics, Invention, University, Navigation, Engineering, Philosophy, Astronomy, Construction, Literacy, Mathematics, Mysticism, Currency, Iron Working, Code of Laws, Writing, Map Making, The Wheel, Masonry, Ceremonial Burial, Bronze Working, Alphabet -> Electronics, Hydro Plant, Hoover Dam, Computers, SETI Program, Advanced Flight, Bomber, Carrier, Rocketry, Nuclear Power, Nuclear Unit, Space Flight, Nuclear Plant, SS Structure, Apollo Program, Plastic, SS Component, Superconductor, Robotics, Fusion Power, SDI Defence, Artillery, Mfg Plant, SS Module Industrialization <- Railroad, Steam Engine, Physics, Invention, Banking, Navigation, Bridge Building, Engineering, Republic, Astronomy, Construction, Trade, Literacy, Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Transport, Factory, Women's Suffrage, Steel, 
                          Corporation, Communism, Battleship, Refining, 
                          Genetic Eng., United Nations, Power Plant, 
                          Combustion, Cure for Cancer, Automobile, Cruiser, 
                          Flight, Armor, Mass Production, Fighter, 
                          Advanced Flight, Labor Union, Submarine, 
                          Mass Transit, Recycling, Nuclear Fission, Bomber, 
                          Carrier, Rocketry, Mech Infantry, Recycling Center, 
                          Manhattan Project, Nuclear Power, Nuclear Unit, 
                          Space Flight, Nuclear Plant, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Electronics       <- Electricity, Metallurgy, Magnetism, Gunpowder, 
                          Physics, Invention, University, Navigation, 
                          Engineering, Philosophy, Astronomy, Construction, 
                          Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Hydro Plant, Hoover Dam, Computers, SETI Program, 
                          Rocketry, Nuclear Power, Nuclear Unit, Space Flight, 
                          Nuclear Plant, SS Structure, Apollo Program, 
                          Plastic, SS Component, Superconductor, Robotics, 
                          Fusion Power, SDI Defence, Artillery, Mfg Plant, 
                          SS Module

     Steel             <- Industrialization, Railroad, Metallurgy, 
                          Steam Engine, Gunpowder, Physics, Invention, 
                          University, Banking, Navigation, Bridge Building, 
                          Engineering, Philosophy, Republic, Astronomy, 
                          Construction, Trade, Literacy, Mathematics, 
                          Mysticism, Currency, Iron Working, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

                       -> Battleship, Automobile, Armor, Mass Production, 
                          Labor Union, Submarine, Mass Transit, Recycling, 
                          Nuclear Fission, Mech Infantry, Recycling Center, 
                          Manhattan Project, Nuclear Power, Nuclear Plant, 
                          Superconductor, Fusion Power, SDI Defence

     Corporation       <- Industrialization, Railroad, Steam Engine, Physics, 
                          Invention, Banking, Navigation, Bridge Building, 
                          Engineering, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Refining, Genetic Eng., Power Plant, Combustion, 
                          Cure for Cancer, Automobile, Cruiser, Flight, Armor, 
                          Mass Production, Fighter, Advanced Flight, 
                          Labor Union, Submarine, Mass Transit, Recycling, 
                          Nuclear Fission, Bomber, Carrier, Rocketry, 
                          Mech Infantry, Recycling Center, Manhattan Project, 
                          Nuclear Power, Nuclear Unit, Space Flight, 
                          Nuclear Plant, SS Structure, Apollo Program, 
                          Plastic, SS Component, Superconductor, Robotics, 
                          Fusion Power, SDI Defence, Artillery, Mfg Plant, 
                          SS Module

     Communism         <- Industrialization, Railroad, Steam Engine, Physics, 
                          Invention, Banking, Navigation, Bridge Building, 
                          Engineering, Philosophy, Republic, Astronomy, 
                          Construction, Trade, Literacy, Mathematics, 
                          Mysticism, Currency, Iron Working, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

                       -> United Nations, Labor Union, Mech Infantry

     Computers         <- Electronics, Electricity, Metallurgy, Magnetism, 
                          Gunpowder, Physics, Invention, University, 
                          Navigation, Engineering, Philosophy, Astronomy, 
                          Construction, Literacy, Mathematics, Mysticism, 
                          Currency, Iron Working, Code of Laws, Writing, 
                          Map Making, The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> SETI Program, Space Flight, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Refining          <- Corporation, Industrialization, Railroad, 
                          Steam Engine, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Power Plant, Combustion, Automobile, Cruiser, 
                          Flight, Armor, Mass Production, Fighter, 
                          Advanced Flight, Labor Union, Submarine, 
                          Mass Transit, Recycling, Nuclear Fission, Bomber, 
                          Carrier, Rocketry, Mech Infantry, Recycling Center, 
                          Manhattan Project, Nuclear Power, Nuclear Unit, 
                          Space Flight, Nuclear Plant, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Genetic Eng.      <- Corporation, Industrialization, Railroad, 
                          Steam Engine, Physics, Invention, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Cure for Cancer

     Combustion        <- Refining, Corporation, Industrialization, Railroad, 
                          Explosives, Steam Engine, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Automobile, Cruiser, Flight, Armor, Mass Production, 
                          Fighter, Advanced Flight, Labor Union, Submarine, 
                          Mass Transit, Recycling, Nuclear Fission, Bomber, 
                          Carrier, Rocketry, Mech Infantry, Recycling Center, 
                          Manhattan Project, Nuclear Power, Nuclear Unit, 
                          Space Flight, Nuclear Plant, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Automobile        <- Combustion, Refining, Corporation, Steel, 
                          Industrialization, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Gunpowder, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Armor, Mass Production, Labor Union, Submarine, 
                          Mass Transit, Recycling, Nuclear Fission, 
                          Mech Infantry, Recycling Center, Manhattan Project, 
                          Nuclear Power, Nuclear Plant, Superconductor, 
                          Fusion Power, SDI Defence

     Flight            <- Combustion, Refining, Corporation, 
                          Industrialization, Railroad, Explosives, 
                          Steam Engine, Gunpowder, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Fighter, Advanced Flight, Bomber, Carrier, Rocketry, 
                          Nuclear Unit, Space Flight, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Mass Production   <- Automobile, Combustion, Refining, Corporation, 
                          Steel, Industrialization, Railroad, Metallurgy, 
                          Explosives, Steam Engine, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Labor Union, Submarine, Mass Transit, Recycling, 
                          Nuclear Fission, Mech Infantry, Recycling Center, 
                          Manhattan Project, Nuclear Power, Nuclear Plant, 
                          Superconductor, Fusion Power, SDI Defence

     Advanced Flight   <- Flight, Combustion, Refining, Corporation, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Bomber, Carrier, Rocketry, Nuclear Unit, 
                          Space Flight, SS Structure, Apollo Program, Plastic, 
                          SS Component, Superconductor, Robotics, 
                          Fusion Power, SDI Defence, Artillery, Mfg Plant, 
                          SS Module

     Labor Union       <- Mass Production, Automobile, Combustion, Refining, 
                          Communism, Corporation, Steel, Industrialization, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Mech Infantry

     Recycling         <- Mass Production, Automobile, Combustion, Refining, 
                          Corporation, Steel, Industrialization, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Gunpowder, 
                          Chemistry, Physics, Invention, University, 
                          Democracy, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Recycling Center

     Nuclear Fission   <- Mass Production, Automobile, Combustion, Refining, 
                          Corporation, Steel, Industrialization, Railroad, 
                          Metallurgy, Explosives, Atomic Theory, Steam Engine, 
                          Gunpowder, Theory of Gravity, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Manhattan Project, Nuclear Power, Nuclear Plant, 
                          Fusion Power

     Rocketry          <- Advanced Flight, Flight, Combustion, Refining, 
                          Corporation, Electronics, Industrialization, 
                          Electricity, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Magnetism, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Nuclear Unit, Space Flight, SS Structure, 
                          Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Nuclear Power     <- Nuclear Fission, Mass Production, Automobile, 
                          Combustion, Refining, Corporation, Steel, 
                          Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Atomic Theory, 
                          Steam Engine, Magnetism, Gunpowder, 
                          Theory of Gravity, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Nuclear Plant, Fusion Power

     Space Flight      <- Rocketry, Advanced Flight, Flight, Combustion, 
                          Refining, Computers, Corporation, Electronics, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> SS Structure, Apollo Program, Plastic, SS Component, 
                          Superconductor, Robotics, Fusion Power, SDI Defence, 
                          Artillery, Mfg Plant, SS Module

     Plastic           <- Space Flight, Rocketry, Advanced Flight, Flight, 
                          Combustion, Refining, Computers, Corporation, 
                          Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> SS Component, Superconductor, Robotics, 
                          Fusion Power, SDI Defence, Artillery, Mfg Plant, 
                          SS Module

     Superconductor    <- Plastic, Space Flight, Rocketry, Advanced Flight, 
                          Mass Production, Flight, Automobile, Combustion, 
                          Refining, Computers, Corporation, Steel, 
                          Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

                       -> Fusion Power, SDI Defence

     Robotics          <- Plastic, Space Flight, Rocketry, Advanced Flight, 
                          Flight, Combustion, Refining, Computers, 
                          Corporation, Electronics, Industrialization, 
                          Electricity, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Magnetism, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

                       -> Artillery, Mfg Plant, SS Module

     Fusion Power      <- Superconductor, Plastic, Space Flight, 
                          Nuclear Power, Rocketry, Nuclear Fission, 
                          Advanced Flight, Mass Production, Flight, 
                          Automobile, Combustion, Refining, Computers, 
                          Corporation, Steel, Electronics, Industrialization, 
                          Electricity, Railroad, Metallurgy, Explosives, 
                          Atomic Theory, Steam Engine, Magnetism, Gunpowder, 
                          Theory of Gravity, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet



     IMPROVEMENTS
     ------------

     Temple            <- Ceremonial Burial

     Palace            <- Masonry

     City Wall         <- Masonry

     Granary           <- Pottery

     Library           <- Writing, Alphabet

     Courthouse        <- Code of Laws, Alphabet

     Marketplace       <- Currency, Bronze Working

     Aqueduct          <- Construction, Currency, Masonry, Bronze Working

     Colosseum         <- Construction, Currency, Masonry, Bronze Working

     Fortress          <- Construction, Currency, Masonry, Bronze Working

     Bank              <- Banking, Republic, Trade, Literacy, Currency, 
                          Code of Laws, Writing, Bronze Working, Alphabet

     Cathedral         <- Religion, Philosophy, Literacy, Mysticism, 
                          Code of Laws, Writing, Ceremonial Burial, Alphabet

     University (Imp)  <- University, Philosophy, Literacy, Mathematics, 
                          Mysticism, Code of Laws, Writing, Masonry, 
                          Ceremonial Burial, Alphabet

     Factory           <- Industrialization, Railroad, Steam Engine, Physics, 
                          Invention, Banking, Navigation, Bridge Building, 
                          Engineering, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Hydro Plant       <- Electronics, Electricity, Metallurgy, Magnetism, 
                          Gunpowder, Physics, Invention, University, 
                          Navigation, Engineering, Philosophy, Astronomy, 
                          Construction, Literacy, Mathematics, Mysticism, 
                          Currency, Iron Working, Code of Laws, Writing, 
                          Map Making, The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Power Plant       <- Refining, Corporation, Industrialization, Railroad, 
                          Steam Engine, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     Mass Transit      <- Mass Production, Automobile, Combustion, Refining, 
                          Corporation, Steel, Industrialization, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Gunpowder, 
                          Chemistry, Physics, Invention, University, Medicine, 
                          Banking, Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Recycling Center  <- Recycling, Mass Production, Automobile, Combustion, 
                          Refining, Corporation, Steel, Industrialization, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Democracy, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Nuclear Plant     <- Nuclear Power, Nuclear Fission, Mass Production, 
                          Automobile, Combustion, Refining, Corporation, 
                          Steel, Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Atomic Theory, 
                          Steam Engine, Magnetism, Gunpowder, 
                          Theory of Gravity, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     SS Structure      <- Space Flight, Rocketry, Advanced Flight, Flight, 
                          Combustion, Refining, Computers, Corporation, 
                          Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     SS Component      <- Plastic, Space Flight, Rocketry, Advanced Flight, 
                          Flight, Combustion, Refining, Computers, 
                          Corporation, Electronics, Industrialization, 
                          Electricity, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Magnetism, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     SDI Defence       <- Superconductor, Plastic, Space Flight, Rocketry, 
                          Advanced Flight, Mass Production, Flight, 
                          Automobile, Combustion, Refining, Computers, 
                          Corporation, Steel, Electronics, Industrialization, 
                          Electricity, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Magnetism, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Mfg Plant         <- Robotics, Plastic, Space Flight, Rocketry, 
                          Advanced Flight, Flight, Combustion, Refining, 
                          Computers, Corporation, Electronics, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     SS Module         <- Robotics, Plastic, Space Flight, Rocketry, 
                          Advanced Flight, Flight, Combustion, Refining, 
                          Computers, Corporation, Electronics, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet



     WONDERS OF THE WORLD
     --------------------

     Pyramids          <- Masonry

     Great Wall        <- Masonry

     Hanging Garden    <- Pottery

     Lighthouse        <- MapMaking, Alphabet

     Oracle            <- Mysticism, Ceremonial Burial

     Great Library     <- Literacy, Code of Laws, Writing, Alphabet

     Copernicus        <- Astronomy, Mathematics, Mysticism, Masonry, 
                          Ceremonial Burial, Alphabet

     Magellan          <- Navigation, Astronomy, Mathematics, Mysticism, 
                          Map Making, Masonry, Ceremonial Burial, Alphabet

     Shakespeare       <- Medicine, Philosophy, Trade, Literacy, Mysticism, 
                          Currency, Code of Laws, Writing, Ceremonial Burial, 
                          Bronze Working, Alphabet

     J.S. Bach         <- Religion, Philosophy, Literacy, Mysticism, 
                          Code of Laws, Writing, Ceremonial Burial, Alphabet

     Michelangelo      <- Religion, Philosophy, Literacy, Mysticism, 
                          Code of Laws, Writing, Ceremonial Burial, Alphabet

     Isaac Newton      <- Theory of Gravity, University, Philosophy, 
                          Astronomy, Literacy, Mathematics, Mysticism, 
                          Code of Laws, Writing, Masonry, Ceremonial Burial, 
                          Alphabet

     Darwin's Voyage   <- Railroad, Steam Engine, Physics, Invention, 
                          Navigation, Bridge Building, Engineering, Astronomy, 
                          Construction, Literacy, Mathematics, Mysticism, 
                          Currency, Iron Working, Code of Laws, Writing, 
                          Map Making, The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Women's Suffrage  <- Industrialization, Railroad, Steam Engine, Physics, 
                          Invention, Banking, Navigation, Bridge Building, 
                          Engineering, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Hoover Dam        <- Electronics, Electricity, Metallurgy, Magnetism, 
                          Gunpowder, Physics, Invention, University, 
                          Navigation, Engineering, Philosophy, Astronomy, 
                          Construction, Literacy, Mathematics, Mysticism, 
                          Currency, Iron Working, Code of Laws, Writing, 
                          Map Making, The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     United Nations    <- Communism, Industrialization, Railroad, 
                          Steam Engine, Physics, Invention, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     SETI Program      <- Computers, Electronics, Electricity, Metallurgy, 
                          Magnetism, Gunpowder, Physics, Invention, 
                          University, Navigation, Engineering, Philosophy, 
                          Astronomy, Construction, Literacy, Mathematics, 
                          Mysticism, Currency, Iron Working, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Cure for Cancer   <- Genetic Eng., Corporation, Industrialization, 
                          Railroad, Steam Engine, Physics, Invention, 
                          Medicine, Banking, Navigation, Bridge Building, 
                          Engineering, Philosophy, Republic, Astronomy, 
                          Construction, Trade, Literacy, Mathematics, 
                          Mysticism, Currency, Iron Working, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Manhattan Project <- Nuclear Fission, Mass Production, Automobile, 
                          Combustion, Refining, Corporation, Steel, 
                          Industrialization, Railroad, Metallurgy, Explosives, 
                          Atomic Theory, Steam Engine, Gunpowder, 
                          Theory of Gravity, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     Apollo Program    <- Space Flight, Rocketry, Advanced Flight, Flight, 
                          Combustion, Refining, Computers, Corporation, 
                          Electronics, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet



     UNITS
     -----

     Chariot           <- The Wheel

     Cavalry           <- Horseback Riding

     Diplomat          <- Writing, Alphabet

     Trireme           <- MapMaking, Alphabet

     Legion            <- Iron Working, Bronze Working

     Catapult          <- Mathematics, Masonry, Alphabet

     Caravan           <- Trade, Currency, Code of Laws, Bronze Working, 
                          Alphabet

     Sail              <- Navigation, Astronomy, Mathematics, Mysticism, 
                          Map Making, Masonry, Ceremonial Burial, Alphabet

     Knight            <- Chivalry, Feudalism, Monarchy, Code of Laws, 
                          Horseback Riding, Masonry, Ceremonial Burial, 
                          Alphabet

     Musketeer         <- Gunpowder, Invention, Engineering, Construction, 
                          Literacy, Currency, Iron Working, Code of Laws, 
                          Writing, The Wheel, Masonry, Bronze Working, 
                          Alphabet

     Frigate           <- Magnetism, Physics, Navigation, Astronomy, 
                          Mathematics, Mysticism, Map Making, Masonry, 
                          Ceremonial Burial, Alphabet

     Ironclad          <- Steam Engine, Physics, Invention, Navigation, 
                          Engineering, Astronomy, Construction, Literacy, 
                          Mathematics, Mysticism, Currency, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Cannon            <- Metallurgy, Gunpowder, Invention, University, 
                          Engineering, Philosophy, Construction, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Rifleman          <- Conscription, Explosives, Gunpowder, Chemistry, 
                          Invention, University, Medicine, Engineering, 
                          Philosophy, Republic, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Transport         <- Industrialization, Railroad, Steam Engine, Physics, 
                          Invention, Banking, Navigation, Bridge Building, 
                          Engineering, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Battleship        <- Steel, Industrialization, Railroad, Metallurgy, 
                          Steam Engine, Gunpowder, Physics, Invention, 
                          University, Banking, Navigation, Bridge Building, 
                          Engineering, Philosophy, Republic, Astronomy, 
                          Construction, Trade, Literacy, Mathematics, 
                          Mysticism, Currency, Iron Working, Code of Laws, 
                          Writing, Map Making, The Wheel, Masonry, 
                          Ceremonial Burial, Bronze Working, Alphabet

     Cruiser           <- Combustion, Refining, Corporation, 
                          Industrialization, Railroad, Explosives, 
                          Steam Engine, Gunpowder, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Armor             <- Automobile, Combustion, Refining, Corporation, 
                          Steel, Industrialization, Railroad, Metallurgy, 
                          Explosives, Steam Engine, Gunpowder, Chemistry, 
                          Physics, Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Fighter           <- Flight, Combustion, Refining, Corporation, 
                          Industrialization, Railroad, Explosives, 
                          Steam Engine, Gunpowder, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Submarine         <- Mass Production, Automobile, Combustion, Refining, 
                          Corporation, Steel, Industrialization, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Gunpowder, 
                          Chemistry, Physics, Invention, University, Medicine, 
                          Banking, Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Bomber            <- Advanced Flight, Flight, Combustion, Refining, 
                          Corporation, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     Carrier           <- Advanced Flight, Flight, Combustion, Refining, 
                          Corporation, Industrialization, Electricity, 
                          Railroad, Metallurgy, Explosives, Steam Engine, 
                          Magnetism, Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     Mech Infantry     <- Labor Union, Mass Production, Automobile, 
                          Combustion, Refining, Communism, Corporation, Steel, 
                          Industrialization, Railroad, Metallurgy, Explosives, 
                          Steam Engine, Gunpowder, Chemistry, Physics, 
                          Invention, University, Medicine, Banking, 
                          Navigation, Bridge Building, Engineering, 
                          Philosophy, Republic, Astronomy, Construction, 
                          Trade, Literacy, Mathematics, Mysticism, Currency, 
                          Iron Working, Code of Laws, Writing, Map Making, 
                          The Wheel, Masonry, Ceremonial Burial, 
                          Bronze Working, Alphabet

     Nuclear Unit      <- Rocketry, Advanced Flight, Flight, Combustion, 
                          Refining, Corporation, Electronics, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet

     Artillery         <- Robotics, Plastic, Space Flight, Rocketry, 
                          Advanced Flight, Flight, Combustion, Refining, 
                          Computers, Corporation, Electronics, 
                          Industrialization, Electricity, Railroad, 
                          Metallurgy, Explosives, Steam Engine, Magnetism, 
                          Gunpowder, Chemistry, Physics, Invention, 
                          University, Medicine, Banking, Navigation, 
                          Bridge Building, Engineering, Philosophy, Republic, 
                          Astronomy, Construction, Trade, Literacy, 
                          Mathematics, Mysticism, Currency, Iron Working, 
                          Code of Laws, Writing, Map Making, The Wheel, 
                          Masonry, Ceremonial Burial, Bronze Working, 
                          Alphabet