THE PLAYER'S CIVILOPEDIA
  
     This file provides an alphabetical reference to the
  technological advancements in Sid Meier's Civilization. It
  allows one to check the blueprints (prerequisites, future
  advancements, and residual benefits) for each advance
  against the needs of the players specific situation. THIS
  FILE IS VERY LONG AND THUS NOT PRACTICAL FOR ON-LINE USE. We
  recommend readers print this file out for "monitor-side"
  reference.
 
     These chunks of wisdom were excerpted from Alan Emrich
  and Johnny Wilson's Sid Meier's Civilization, Or Rome On
  640K A Day, an excellent supplement and strategy guide done
  in close collaboration with Sid Meier.
  
  Advanced Flight
     Requires: Flight, Electricity
     Leads to: Rocketry.
     Makes available: Bomber and Aircraft Carrier Units.
     Advanced Flight is an important milestone on the road to
 
  Space Flight and the colonization of Alpha Centauri, and the
  immediate military advantages are impressive. Aircraft
  Carrier units possess the best defense in the game and, when
  parked in a coastal city with City Walls, can be nearly
  impossible to destroy. Bomber units, on the other hand, are
  a fine offensive tool. They can block enemy units, pillage
  enemy resources, attack cities while negating the effects of
  City Walls, and can be based on Carriers for an extra
  extension to their range. While not an urgent discovery,
  Advanced Flight is certainly an important and highly useful
  advance for both war mongers and space colonizers.
  
  Alphabet
     Requires: None.
     Leads to: Code of Laws, Map Making, Math, Writing
     All good things spring forth from the Alphabet. With the
  possible exception of Pottery, it should be the first thing
  a player discovers. Short of an urgent military necessity
  requiring Bronze Working, don't waste a moment.
 
  Astronomy
     Requires: Mysticism, Mathematics
     Leads to: Navigation, Theory of Gravity
     Makes available: Copernicus' Observatory
     Astronomy is primarily a stepping stone on the way to
  Navigation, which leads to the crucial, world-exploring Sail
  units and the never-expiring Magellan's Expedition wonder.
  It is THE door to modern science.
  
  Atomic Theory
 
     Requires: Theory of Gravity, Physics
     Leads to: Nuclear Fission
     As far as advances go, Atomic Theory does not offer much.
  It leads toward the Manhattan Project wonder and Nuclear
  Power, and thus can be put off until one has a pressing need
  for a cleaner fuel supply or nuclear superiority.
  
  Automobile
     Requires: Combustion, Steel
     Leads to: Mass Production
     Makes available: Armor Units
     Makes Obsolete: Copernicus' Observatory and Knight Units.
     The Automobile advance is a can of worms. While allowing
  players to build the best overall military unit in the game,
  it also makes Knights obsolete and increases your pollution
  problems considerably. Fortunately, it brings the player 1
  step from the Mass Production advance which negates the
  population pollution effect, and 2 steps from the Recycling
  advance which reduces industrial pollution to its lowest
  possible level.
 
  Banking
     Requires: Trade, The Republic
     Leads to: Industrialization, Corporation
     Makes available: Banks
     Banks become available with the advent of banking, which
  increase luxury item and coin production by 50%. It also
  comprises half of the ingredients necessary for the
  Industrialization advance.
 
  Bridge Building
     Requires: Iron Working, Construction
     Leads to: Railroad
     Makes available: Roads on river squares.
     In itself, Bridge Building is not an important advance
  (unless your empire is divided by numerous rivers), but its
  necessity in acquiring the essential Railroad advance make
  it a priority.
  
  Bronze Working
 
     Leads to: Currency, Iron Working
     Makes available: Phalanx Units, Colossus wonder
     The closer you discover a neighboring civilization, the
  more important this advance becomes. The Phalanx units it
  provides will be your primary defensive unit until the
  invention of Gunpowder. The Colossus wonder is also very
  useful, being the cheapest to construct and adding to your
  trade production during the crucial early years when they
  are needed the most.
 
  
  Ceremonial Burial
     Requires: None
     Leads to: Monarchy, Mysticism
     Makes available: Temples
     This advance does not sound as important as it really is.
  The immediate affect is the ability to construct temples
  (absolutely necessary early on at higher difficulty levels)
  which in turn prevent volcano disasters. It is also the
  building block to Monarchy and Mysticism, two other crucial
  advances. Ceremonial Burial -- dig it!
  
  Chemistry
     Requires: University, Medicine
     Leads to: Refining, Nuclear Power
     Chemistry has no immediate benefits, though it is a major
  gateway to many modern era advances.
  
  Chivalry
     Requires: Feudalism, Horseback Riding
     Leads to: Nothing
     Makes available: Knight Units
     Makes obsolete: Chariots
     If you are a warring type of leader, Chivalry is
  certainly not the dead end that it seems. The Knight Units
  it makes available are the best all around units on the
  board until Gunpowder and Metallurgy bring in heavier fire
  power. Peacefully situated civilizations may opt to leave
  Feudalism and Chivalry alone.
 
  Code of Laws
     Requires: Alphabet
     Leads to: Monarchy, Trade, Literacy, The Republic
     Makes available: Courthouses
     Code of Laws is a major gateway in the early portion of
  the game. Unless in a war situation requiring the urgent
  research of Bronze or Iron working, one should get their
  Code of Laws established as soon as possible.
  
  Combustion
     Requires: Refining, Explosives
     Leads to: Flight, Automobile
     Makes available: Cruisers
     Makes obsolete: Ironclads, Barracks
     Two very important advances depend on Combustion: Flight
  and the Automobile. While the immediate effect of being able
  to build Cruisers is useful (especially for examining
  unexplored oceans), the fact that Barracks become obsolete
  for the 2d time might cause some consternation. Not only
  must Barracks be rebuilt, but their maintenance costs
  increase as well.
     Note: New icons appear for Granaries, Marketplaces, and
  Barracks in the View City display.
  
  Communism
     Requires: Philosophy, Industrialization
     Leads to: Labor Unions
     Makes available: United Nations
     Makes obsolete: Pyramids and Michelangelo's Chapel
     Communism should be pursued under 3 conditions 1) you
  need to improve your war effort by adding Mechanized
  Infantry to your bag of tricks, 2) you're losing a war with
  another civilization and need the United Nations to
  establish peace, 3) you don't have the Pyramids or
  Michelangelo's Chapel which become obsolete. Otherwise,
  except as a tool for starting wars, Communism is a pretty
  useless form of government 
  
  Computers
     Requires: Mathematics, Electronics
     Leads to: Space Flight, Robotics
     Makes available: SETI program
     Computers are an important way-point to a player's entire
  space program and, ultimately, Robotics (where Artillery
  units and Manufacturing Plants are a MAJOR reward). The SETI
  Program wonder, with its +50% gross light bulb production,
  while useful, arrives at a fairly late stage in the game
  after most of the discoveries have already been made. Still,
  every wonder is worth 20 Civ Points and having the SETI
  program makes the value of the additional 5 points scored
  for each "Future Advance" far more attainable.
  
  Conscription
     Requires: The Republic, Explosives
     Leads to: Nothing
     Makes available: Riflemen Units
     Makes obsolete: Legions, Musketeers
     There is only one reason to develop Conscription -- 
  Riflemen units, the best military value in the game and a
  great boon for defense. If readying the defenses is not a
  priority, research elsewhere. Remember, though, you can
  never be too prepared for a sneak attack.
  
  Construction
     Requires: Masonry, Currency
     Leads to: Engineering, Bridge Building
     Makes available: Fortresses, Aqueducts, Colosseums
     Construction doesn't seem to get a lot of respect until
  after "something happens". After a city is denied growth
  from 10 to 11, or when the unrest in a city becomes too
  acute to ignore any longer, only then do players seem to
  appreciate the value of Construction. A little foresight in
  the development of construction can save many headaches.
  
  Currency
     Requires: Bronze Working
     Leads to: Trade, Construction
     Makes available: Marketplaces
     The Currency advance is where building a civilizations'
  fiscal picture really begins. With a Marketplace
  improvement, a city will generate 50% more coins. Currency
  also gets one on the roads toward trade and the precious
  Caravan units, and is a must when moving toward the more
  advanced government types.
  
  Democracy
     Requires: Philosophy, Literacy
     Leads to: Recycling
     Winston Churchill aptly described democracy as "the worst
  form of government, except for all others." It is the
  highest level that a civilization can achieve and eliminates
  all corruption. Unfortunately, city unrest must be watched
  diligently, for the state of Anarchy following overthrow of
  a democratic government is twice as long (2-8 turns), and
  the double "sad faces" created when troops leave home make
  Democracy a terrible war government. One should only rush
  the discovery of Democracy when the borders are secure, the
  prospects for world peace are promising and there are no
  large expeditions off abroad.
 
  Electricity
     Requires: Magnetism, Metallurgy
     Leads to: Electronics, Advanced Flight
     Makes obsolete: Colossus wonder
     As a civilization advance, Electricity just doesn't have
  a lot of spark. While it can quickly take a player to
  Electronics (nice for its Hoover Dam wonder) and from there
  to Computers, it is best left for the big push toward the
  end game. If you have the Colossus wonder, be sure your civ
  can take the revenue loss due to its obsolescence before
  developing this advance.
  
  Electronics
     Requires: Electricity
     Leads to: Computers, Rocketry, Nuclear Power
     Makes available: Hoover Dam, Hydro Plants
     Makes obsolete: Shakespeare's Theatre
     After the discovery of Electricity, one should quickly
  follow up the discovery of Electronics since both the Hoover
  Dam wonder and the Hydro Plant improvement are excellent
  purchases. Not only do Hydro plants and the Hoover Dam
  provide 50% more shields to an industrialized city, but they
  also reduce the industrial side of the pollution formula by
  50%. The Hoover Dam provides power to all cities on a
  continent, so one should choose the sight for this wonder
  with care.
  
  Engineering
     Requires: The Wheel, Construction
     Leads to: Electronics, Invention
     While Engineering should be selected in the early portion
  of the game and has to be acquired before Industrialization,
  it should not be among the 1st handful of advances made,
  since it offers no immediate advantages.
  
  Explosives
     Requires: Gunpowder, Chemistry
     Leads to: Combustion, Conscription
     Though it sounds powerful, Explosives is another of the
  many intermediate discoveries which reap the player no
  immediate benefit. While Combustion is usually a ways off
  due to the need for Refining, Conscription is often right at
  hand. If you are under attack (or you are busy preparing to
  be attacked like a good paranoid!), the defensive advantage
  of Conscription's inexpensive riflemen might be worth a
  quick dash through Explosives. Otherwise, players should
  pursue other advances with more immediate rewards.

  Feudalism
     Requires: Masonry, Monarchy
     Leads to: Chivalry
     There's only one reason to pursue Feudalism -- to pursue
  Chivalry and make Knights available. Knights will dominate
  the battlefield for a long time. If caught up in the
  ancient-to-medieval arms race, one might be pressed into
  pursuing Feudalism. Otherwise, it can easily wait.
  
  Flight
     Requires: Combustion, Physics
     Leads to: Advanced Flight
     Makes available: Fighter Units
     The first step down the road to colonizing Alpha Centauri
  is Flight (which proceeds through Advanced Flight, Rocketry,
  and Space Flight). The immediate benefit of Flight is the
  Fighter Unit. Note that fighters were 'upgunned' during the
  final playtesting stage of the game, and now posses a 4
  attack and a 2 defense, and not the 3 - 3 values indicated
  in the rule book. While Fighters might take a while to get
  to the front, they are quite handy once they get there.
 
  Fusion Power
     Requires: Nuclear Power, Superconductor
     Leads to: Futuristic Advances
     Makes obsolete: Hydro Plants
     Fusion Power is usually the last advance one achieves
  before researching Futuristic Advances. Aside from something
  to do with scientific research production, Fusion Power
  actually does contribute one thing. With Fusion Power, the
  risk of nuclear melt-down is completely eliminated, making
  Nuclear Plants the energy source of choice for their lower
  building and maintenance costs and, now, absolute safety.
  After discovering Fusion Power, one must decide whether to
  keep the light bulbs burning to achieve Futuristic Advances,
  or to go completely hedonistic with ones luxury rate.
  
  Futuristic Advance
     Requires: Fusion Power
     Leads to: More Futuristic Advances
     During playtesting, this advance was known as "The
  Meaning of Life" and, as the rules state, was worth 10
  Civilization Points each. In the final code, they became a
  generic Futuristic Advance and are worth only 5 Civilization
  Points. The question the player must ask is whether they are
  a good value at only 5 points each, whereas the resources
  used to produce them might yield more in the final outcome.
  
  Genetic Engineering
     Requires: Medicine, The Corporation
     Leads to: Nothing
     Makes available: Cure for Cancer
     The single reason to pursue Genetic Engineering is the
  Cure For Cancer wonder. While the 20 Civilization Points for
  the wonder and the extra happy face amongst each city's
  populous are nothing to sneeze at, Genetic Engineering can
  wait for more pressing discoveries to be made. This Advance
  is usually only to be pursued by "idle minds", as it were.
  
  Gunpowder
     Requires: Invention, Iron Working
     Leads to: Metallurgy, Explosives
     Makes available: Musketeers
     Makes obsolete: Barracks, Militia, Phalanx, The Great
  Wall
     Gunpowder is one of the 3 big Advances that really
  changes the complexity of the game. Gunpowder makes all
  Barracks obsolete and, when rebuilt, have a higher
  maintenance cost. While Gunpowder makes the Great Wall,
  Militia, and Phalanx units obsolete, it does allow
  Musketeers to be built (with their excellent defense
  strengths). Gunpowder is usually a priority Advance, just
  don't forget to sell off all your old Barracks immediately
  prior to its discovery.
  
  Horseback Riding
     Requires: Nothing.
     Leads to: Chivalry
     Makes available: Cavalry Units
     Horseback Riding offers very little. While it is required
  to obtain Chivalry and the Knight unit, it is ultimately a
  dead end path. This Advance can be stabled for a while
  unless there are long term prospects for war ahead. If it's
  looking hostile out there, one had better saddle up and move
  'em out.
  
  Industrialization
     Requires: Railroad, Banking
     Leads to: Steel, The Corporation, Communism
     Makes available: Women's Suffrage, Transports, Factories
     Makes obsolete: Frigates
     Industrialization kicks off the modern era, and one is
  advised to acquire it with all haste. Nearly every thing
  about it is positive. Factories will increase production in
  cities by 50%; Transports greatly enhance sealift capacity;
  and Women's Suffrage is, arguably, the single most important
  wonder in the game. The downside is that population
  pollution begins to be factored into the pollution equation
  (see the Pollution Formula in the other Civilization hint
  file).
  
  Invention
     Requires: Engineering, Literacy
     Leads to: Steam Engine, Gunpowder
     Makes obsolete: Hanging Gardens
     With necessity as its mother, Invention is a linchpin
  Advance on the road to both the Steam Engine (which leads to
  the critical Railroad advance) and Gunpowder (which takes
  one into a grand new epoch of warfare). Of course, if you
  don't have the Hanging Gardens wonder, there's the extra
  satisfaction of negating that wonder's benefits for an
  opponent. The discovery of Invention can wait for
  emergencies, but should remain a fairly high priority.
  Note: Advisors take on their modern look once a civilization
  achieves Invention.
  
  Iron Working
     Requires: Bronze Working
     Leads to: Bridge Building, Gunpowder
     Makes available: Legions
     Beside providing the short term advantage of cheap
  offensive units, Iron Working is one of the key basic
  building blocks of any budding Civilization.
 
  Labor Union
     Requires: Mass Production, Communism
     Leads to: Nothing
     Makes available: Mech Infantry
     One can count on one finger the reasons to discover Labor
  Unions -- Mechanized Infantry. The best defense in the game,
  combined with enough speed to keep up with Armor and
  Artillery Units, makes Mech Infantry a critical piece on the
  battlefield. These units are not absolutely necessary,
  however, as the cheaper Riflemen units can do the job of
  city defense while other, more pressing, advances are
  pursued.
  
  Literacy
     Requires: Writing, Code of Laws
     Leads to: Democracy, Invention, Philosophy, & The
  Republic
     Makes available: The Great Library
     Where would civilization be without Literacy? (Not
  reading this file, certainly.) Like Philosophy, it is a tree
  with many branches, opening up many important Advances to
  discovery. Paramount among them is the Republic. If times
  are peaceful, upgrading to this form of government will
  increase trade dramatically. The Great Library, too, can be
  a great help, especially when one starts the game in an
  isolated position.
  
  Magnetism
     Requires: Navigation, Physics
     Leads to: Electricity
     Makes available: Frigates
     Makes obsolete: Sail units and the Lighthouse wonder.
     While the Frigate unit is nice (having the same cost as
  the Sail unit, doubling its combat strength and adding an
  extra unit of carrying capacity), the real point of
  discovering Magnetism is to get to Electricity. However,
  while Electricity is the path to high-tech advances, it will
  take time to make that path bear fruit. Consequently,
  Magnetism can wait for more pressing Advances which offer
  more immediate returns.
  
  Map Making
     Requires: Alphabet
     Leads to: Navigation
     Makes available: Triremes, Lighthouse
     The need for Map Making is usually directly proportional
  to the isolation of one's starting position. If one starts
  on a small island, it is absolutely vital that one gets
  Triremes poking around in the inky black in search of new
  lands to settle.
  
  Masonry
     Requires: Nothing
     Leads to: Mathematics, Feudalism, Construction
     Makes available: The Great Wall, Pyramids, Palace, City
  Walls
     Unless one is in a hurry to get Triremes or Monarchy,
  Masonry is the perfect 2nd or 3rd research choice (after
  Pottery and, perhaps, the Alphabet). City Walls are mini-
  wonders of their own (protecting against floods and greatly
  improving city defense), and the Pyramids and the Great Wall
  are both highly useful.
  
  Mass Production
     Requires: Automobile, The Corporation
     Leads to: Nuclear Fission, Superconductor, Recycling,
  Labor Union
     Makes available: Submarines, Mass Transit
     Mass Production is both a kiss and a curse. The curse is
  that the pollution formula takes a jump and now includes 75%
  of a city's population (up from 50% with the Automobile).
  The kiss, however, is that the Mass Transit improvement will
  completely eliminate a city's population pollution factor. 
  
  Mathematics
     Requires: Alphabet, Masonry
     Leads to: Astronomy, Physics, University, Computers
     Makes available: Catapults
     Mathematics is a key building block for many essential
  advances and makes the ancient offensive juggernauts, the
  Catapults, available (helpful in both attacking and
  defending young cities). 
  
  Medicine
     Requires: Philosophy, Trade
     Leads to: Chemistry, Genetic Engineering
     Makes available: Shakespeare's Theatre
     Medicine begets Chemistry. Chemistry begets the modern
  era. Medicine also inoculates one's civ against plague. The
  Shakespeare's Theatre wonder is made available by this
  advance, though the wonder actually does very little for a
  very limited time. (See the Wonders section).
  
  Metallurgy
     Requires: Gunpowder, University
     Leads to: Steel, Electricity
     Makes available: Cannons
     As if being able to replace Catapults with Cannons isn't
  enough, Metallurgy is also required for discovering both
  Steel and Electricity. The urgency with which one pursues
  Metallurgy usually depends on one's pressing need for
  Cannons, as a rule. When in doubt what to research next,
  Metallurgy is a safe bet.
  
  Monarchy
     Requires: Ceremonial Burial, Code of Laws
     Leads to: Feudalism
     Not only is Monarchy necessary on the road to Chivalry,
  it is also the government of progress during the early
  stages of the game. With Monarchy, both irrigation and
  mining become useful for city growth, and corruption is
  reduced a bit. No less important is the fact that Monarchies
  can declare war on other players at will, ignore their peace
  overtures and never have to cope with a meddlesome Senate
  overruling their "divinely inspired" will. Monarchy always
  makes for a good "war government".
  
  Mysticism
     Requires: Ceremonial Burial
     Leads to: Astronomy, Philosophy
     Makes available: Oracle of Delphi
     Part religion, part science, it's a wonder that Mysticism
  helps along both developmental paths. For religion, it
  doubles the effect of Temples which will then make 2 unhappy
  people mollified. Additionally, with the Oracle wonder,
  Temples double their effect again making 4 unhappy citizens
  content. As for science, Mysticism leads to Astronomy and
  then to Navigation. Likewise, the Philosophy advance
  requires this mystical world view.

  Navigation
     Requires: Map Making, Astronomy
     Leads to: Physics, Magnetism
     Makes available: Magellan's Expedition, Sail Units
     Navigation, like Gunpowder and Industrialization, changes
  the nature of the game. With Navigation, one can build Sail
  units and explore the world. In so doing, one can establish
  far-flung embassies, trade routes and empires. Navigation
  also leads to the important advance of Physics and the
  Magellan's Expedition wonder is one of the best since it
  gives every ship an extra movement point and never expires.
  
  Nuclear Fission
     Requires: Mass Production, Atomic Theory
     Leads to: Nuclear Power
     Makes available: Manhattan Project
     Makes obsolete: Isaac Newton's College
     When heading down the backstretch of technology, there
  appears Nuclear Fission. While this Advance turns the lights
  out at Isaac Newton's College, it also affords one the
  opportunity to pursue the Manhattan Project. Global
  thermonuclear warfare aside, the peaceful uses for Nuclear
  Power will become available with that advance (as will a
  reduction by 50% of industrial pollution where a Nuclear
  Plant exists). Ultimately, this will lead to Fusion Power,
  at which point nuclear power is rendered completely
  harmless.
  
  Nuclear Power
     Requires: Nuclear Fission, Electronics
     Leads to: Fusion Power
     Makes available: Nuclear Plants
     Nuclear Power in Civilization is clean and cheap. Like
  Hydro Plants, Nuclear Plants cut industrial pollution by 50%
  and costs half as much to maintain. There is the small
  threat of nuclear melt-down if a city housing a plant goes
  into civil disorder, but this threat is removed once one
  moves on to Fusion Power.
 
  Philosophy
     Requires: Mysticism, Literacy
     Leads to: Medicine, Democracy, University, Religion,
  Communism
     Philosophy is THE portal to the world of ideas. While not
  every one of its branches is a prize, certainly Democracy
  (the highest form of government in the game) and Religion
  with its cheep, mass mollifying Cathedrals, are winners.
  Players are certainly urged to pursue Philosophy with all
  possible speed. Philosophy -- one Kant win without it.

  Physics
     Requires: Mathematics, Navigation
     Leads to: Atomic Theory, Magnetism, Steam Engine, Flight
     Physics is THE advance of the modern age. Atomic theory,
  Magnetism, Electricity, Steam Engines, Railroads, and Flight
  are its progeny. It gives one a lot of flexibility -- so get
  'physic'al as soon as possible.
  
  Plastics
     Requires: Refining, Space Flight
     Leads to: Superconductor, Robotics
     Makes available: Space ark Components (with Apollo
  Program)
     If one is able to develop Plastics, one is on the home
  stretch of Civilization. It is key to two important
  advances, the Superconductor and its fruit -- SDI defense,
  and, Robotics with its -- Manufacturing Plants and Artillery
  Units. Plastics does have a negative side; it raises the
  population pollution factor in the pollution equation to
  100%. (See the Formula in the other Civ hinte file).
  
  Pottery
     Requires: Nothing
     Leads to: Nothing
     Makes available: Granaries, Hanging Gardens
     With the possible exception of the Alphabet, Pottery
  should be one of the 1st advances a budding civilization
  pursues. While it leads nowhere, Granaries are vital to city
  growth and prosperity, and protect against famine.
     The Hanging Gardens wonder is marginally useful on the
  lower levels, becoming increasingly helpful at higher
  difficulty levels where unrest hits every city with its 3rd
  or 4th civie.
  
  Railroad
     Requires: Steam Engine, Bridge Building
     Leads to: Industrialization
     Makes available: Darwin's Voyage, Railroads (duh)
     The bullet train to the big time beings with the
  Railroad. With an extensive rail network throughout a
  civilization, one can get their troops anywhere in their
  empire in one move (avoid moving through cities!). One
  shouldn't limit their rails to a single transportation
  network line. Rails increase the productivity of any square
  (even ocean squares!!) by 50%, spurring a huge leap in
  income and productivity levels. All aboard!
  
  Recycling
     Requires: Mass Production, Democracy
     Leads to: Nothing
     Makes available: Recycling Centers
     This is a dead end Advance with but a single purpose;
  Recycling Centers. While a Hydro or Nuclear Power Plant will
  reduce industrial pollution by 50%, a Recycling Center will
  knock it down by 67%. For large industrial centers with
  large pollution problems, Recycling is the answer. But if
  pollution is no a major problem, one is best advised to put
  their shield resources somewhere else.
 
  Refining
     Requires: Chemistry, The Corporation
     Leads to: Combustion, Plastics
     Makes available: Power Plant
     Refining bridges the gap between 19th and 20th century
  technology, leading to the all important Combustion Advance.
  It also provides the game's 1st power source, the Power
  Plant. The Power Plant description in the documentation (pg.
  80) is erroneous. It states that Plants "increase...
  pollution significantly", when in fact Power Plants have no
  direct impact on the Pollution formula except to increase
  productivity by 50% (as do all energy sources).
  
  Religion
     Requires: Philosophy, Writing
     Leads to: Nothing
     Makes available: Cathedrals, J.S. Bach's Cathedral,
                      Michelangelo's Cathedral
     Makes obsolete: Oracle wonder
     Though a dead-end technology, Religion is absolutely key
  to building large cities. The Cathedral improvements it
  makes available are an improvement on Colosseums, making 4
  people content as opposed to 3, and costing 3 coins to
  maintain a turn as opposed to 4. It also opens up the way
  for J.S. Bach's Cathedral, one of the most useful and long
  lived wonders in the game.
  
  Robotics
     Requires: Plastics, Computers
     Leads to: Nothing
     Makes available: Artillery, Manufacturing Plants,
                      Space ark Modules
     Makes obsolete: Cannons
     Robotics is a boon to nearly every aspect of the game. In
  war matters, it provides the most potent offensive weapon in
  the game. Economically, it makes available the Manufacturing
  Plants which nearly doubles a city's productivity. It also
  allows one to create the Civilization score enhancing
  population modules for the Space ark.
 
  Rocketry
     Requires: Advanced Flight, Electronics
     Leads to: Space Flight
     Makes available: Nuclear Unit (with Manhattan Project)
     The last milestone before Space Flight, Rocketry also
  unleashes the devastating Nuclear units. Players are wise to
  continue to aggressively pursue their space program after
  the discovery of Rocketry, since the only thing that can
  prevent nuclear devastation is the SDI improvement, which
  lay down that road. Nuke other players conservatively. Every
  polluted square one can see is another negative 10 civ
  points and other fine mess to clean up before global warming
  sets in.
  
  Space Flight
     Requires: Computers, Rocketry
     Leads to: Plastics
     Makes available: Apollo Program, Space Ark Structure
     Space Flight officially opens up the space age. Once the
  Apollo program is developed by any player, any other player
  may begin their Space Ark. Once one has developed Space
  Flight, he should race toward Plastics and the wonders
  beyond.
  
  Steam Engine
     Requires: Physics, Invention
     Leads to: Railroad
     Makes available: Ironclads
     Usually lost in the shuffle of other Advances, a good
  case can be made for developing the Steam Engine
  expeditiously. Like Britannia, the Ironclad will rule the
  waves for many years -- essential for island kingdoms.
  Moreover, the Steam Engine is required for the Railroad
  advance, one of the most important in the game.
  
  Steel
     Requires: Metallurgy, Industrialization
     Leads to: Automobile
     Makes available: Battleships
     Battleships, Battleships, Battleships. Need more be said?
  These units hit hard and take a beating, can shore bombard
  enemy units and cities, and are essential to 'sea'-
  periority. Battleships, live them, learn them, love them.
  
  Superconductor
     Requires: Plastics, Mass Production
     Leads to: Fusion Power
     Makes available: SDI Defense
     Superconductors are only necessary when the threat of
  nuclear annihilation is loose throughout the world. If
  there's no threat, put your shields to better use.
  
  The Corporation
     Requires: Banking, Industrialization
     Leads to: Mass Production, Genetic Engineering, Refining
     The Corporation is a modern conduit to many other
  advances. It is the business equivalent of the Philosophy
  advance which will thrust one toward the highly desired Mass
  Production and Refining technologies.
 
  Theory of Gravity
     Requires: Astronomy, University
     Leads to: Atomic Theory
     Makes available: Isaac Newton's College
     The Theory of Gravity just isn't big news. While Isaac
  Newton's College wonder is a great light bulb generator for
  a long time (until Nuclear Fission), the Theory of Gravity
  doesn't do much else. Until one is ready to start splitting
  atoms, one can let this advance float.
 
  The Republic
     Requires: Code of Laws, Literacy
     Leads to: Banking, Conscription
     This is the 1st of the 2 representative governments that
  become available in Civilization. One can switch to this
  form of government in order to promote economic growth while
  still maintaining some ability to wage an offensive was. One
  can actually play an entire game without leaving The
  Republic. If one is looking to upgrade the empire, one need
  only vote for The Republic (and move faster than the
  Senate).
  
  The Wheel
     Requires: Nothing
     Leads to: Engineering
     Makes available: Chariots
     This is another of the early advances which can either be
  essential or useless depending on the world situation. If
  one is isolated from others from the go, the Wheel can wait.
  If war is in the air, one need put these wheels to the road
  and bring the war home to the enemy.
  
  Trade
     Requires: Currency, Code of Laws
     Leads to: Medicine, Banking
     Makes available: Caravan
     It seems Caravan units are often overlooked by many
  Civilization players. They are invaluable for their
  abilities to increase trade in one's empire and expedite the
  development of wonders. Note that the documentation is
  misleading regarding trade in that it suggests that the
  distance between 2 trading cities affects the volume of
  trade. Distance only comes into play when computing the
  initial trade route bonus but not in the overall volume of
  trade generated each turn.
  
  University
     Requires: Mathematics, Philosophy
     Leads to: Chemistry, Metallurgy, Theory of Gravity
     Makes available: Universities
     Makes obsolete: The Great Library
     If one has fallen behind in the tech race and has built
  the Great Library to remedy that, then one might hesitate
  before developing the University. However, if in the lead,
  one had just as well develop the University and maintain
  that position. 
  
  Writing
     Requires: Alphabet
     Leads to: Religion, Literacy
     Makes available: Libraries, Diplomats
     One might think of Writing as the narrow end of the
  scholarly telescope. While peering through it, one will pass
  through the ever wider channels of Literacy and Philosophy.
  This fact, combined with the usefulness of Diplomats, make
  Writing an advance to put at the top of your list.
        - Elliott

 ...!{ philabs | yale | oliveb | decvax | iscuva}!oliafd!elliott