Warning: This page may contain spoilers. Please stop reading if you wish to find your own winning strategy for C-Evo.
Although there are an almost infinite number of winning strategies, a typical approach may include the following.
- Main article: C-evo: Strategies for first few turns
Increase research up to 100%; keep research as high as possible as long as your nation is not too short of money.
First (as all AI nations seem to do) you could research "The Wheel" to add trade to some roaded tiles. (It may be advantageous to defer that until you can gain half of it in an exchange; but research it if you seem to be taking ages before meeting anyone.)
Get your settler to add irrigation and roads to tiles you are using or will soon want to use, particularly on grassland (but irrigation there is of value only after you change government) and plains. Note that you cannot yet put roads on river tiles. Try to connect cities with roads; if needing to choose between hill and forest or jungle or swamp, choose the hill because you may later want to convert the other, after which a road will take less time.
Next, you could (as most AI nations do) research Warrior Code to allow you to research new ground units, then "Horseback Riding" to add to the permissible weight of those units and create horsemen that may quickly conquer other nearby nations or at least punish anyone who attacks you.
However, in anticipation of getting help with two or three of the military advances from trading with other nations, you could first focus on Map Making and Bridge Building then (after you know Bronze Working) Iron Working.
The first unit you build should be a militia for initial defense then exploring. At this stage no other nation can build anything strong enough to defeat a militia sitting in your capital.
After you have built a militia or two (or maybe three, depending on city growth rate), build a Town Guard, which defends against hostile militia and gives your people extra morale to allow more growth, though at a cost - one material resource per turn. Then build more militia for exploration until you have Warrior Code and can start on the Barracks. (See C-evo advances affecting units/ground for details of how to create new units efficiently.)
Your initial settler belongs to no city and is therefore not costing you food or potentially reducing resources; it therefore makes sense to keep it for development for a long time and build new settlers soon to create new cities.
Make sure that there are at least two good food tiles around each new city, and build a town hall (otherwise the town doesn't contribute to research or tax), and either build or import a defender unit (possibly a Town Guard in the early stages until you can build stronger defenders).
For each city, soon you may want a granary if growth is two or more food per turn, and you will definitely want a temple. As the cities grow, build marketplaces, libraries (but beware of the cost - much more than in Civ2), and exploring units. As the cities grow larger, build barracks, attacking units, and "settler" units (to create additional cities, roads, irrigation, and maybe fortresses).
Try to gain a new technology about every seven turns (or sooner). Research Monarchy and move to that form of government as soon as convenient (but taking care that you do not leave any city trying to support many more than one unit for every two population points, or you may lose units).
Select the "Wonders" and advances that best suit your strategy. If you plan to build any Wonders (which are almost essential if you want to win except at the easiest levels), The Colossus (needing Bronze Working) is the best to start with because it reduces the cost of all others.
If you have coastal cities, consider building The Lighthouse to add a resource to each water tile. (Then aim to be the first or second player to research Steel so that you can build Eiffel Tower and make that Wonder (and others) permanently effective.)
As technology advances and more cities continue to grow, build aqueducts and theaters or cathedrals to allow further expansion. You can't make your city size larger than 12 until you get Sanitation, which has a long technology path, so create settlers with any city that reaches 11 and is still producing lots of surplus food.
If you have five or more cities, consider researching Engineering early so as to build a Great Wall, which is a permanent State Improvement that counts as "City Walls" in each city on its continent. With maintenance cost of 4, it is profitable as soon as you have 5 or more cities. However, it is of no use against enemy ground units that have Artillery. (Walls do, however, preserve population under attack by naval units.)
Establish contact with neighboring nations, and make decisions whether to attack neighbors or to form a treaty or even an alliance with them. Form friendships with many nations in case they are willing to trade or sell technologies unless they are clearly weaker than you and occupying your expansion path. An alliance lets your units wander freely through your ally's territory so that you can see what they have and reach other nations beyond them; later you can use Special Commandos for the same purpose without an alliance.
If you decide to go to war, attacks work best if there is at least a three-to-one attacker-to-defender ratio, though you may be lucky with a roving unit that has reasonable attack strength and enough defensive strength to hold any city it captures. The "Great Wall" State Improvement may be particularly useful at this stage, giving an instant wall to newly captured cities.
If invaded, particularly if it is by a stronger nation, your first priority should be to defend your cities. Overweight units are often the key, with a barracks in each city for quick recovery. An excellent alternative, if you have researtched Flight, is the use of air units, which cannot be dislodged except by other air units.
The arrival of Science and the Industrial Revolution brings factories and pollution, as well as dramatically stronger military and cultivation units. The railroad speeds movement and development, and it increases material extraction unless you are still under Despotism. Consider moving to a Democracy form of government, and usually the player who builds the "Statue of Liberty" and "Eiffel Tower" Wonders will wind up as the game winner. Important strategic choices here include whether to attack your strongest opponent, attack weaker opponents, or build up resources and existing territory.
Wonders in general: each adds two morale points to its city. If you have Bach's Cathedral, no city will ever need more than three wonders for full potential morale. Best to stop at two if possible, which allows for a population of 20. One of your cities should be kept wonder-free so as not to waste wonders when you give it the Colosseum to replace its temple, theater, and cathedral.
In the Mass Production era, the emphasis is on controlling tiles which contain the three different types of "special resources" needed to build the game-winning spaceship. Because of the rare "special resources" needed to build the spaceship, you will likely have to engage in some conquest of neighboring territory to capture or build a city that can use each of the three "special resources" you will need. While one of the AI players may actually sell you spaceship modules, if you don't have access to all three types of "special resources" needed, you cannot win the game.
Use of air power and naval power can be especially useful; for example, use air units with spare fuel to hover and form a defensive shield around a newly captured city.
Cities produce more with nuclear power plants (or their replacement, the Hoover Dam) and with recycling facilities to reduce pollution, with a particular focus on those cities with the special resources. Cities grow faster with Supermarkets (needing Refrigeration) - even if there's no farmland, the central tile produces more food. Even Tundra responds to double irrigation, resulting in three food plus one trade, which may help a city grow fast enough to be able to maximize its resource potential when it starts producing space ship parts. Near the end, your spare cash will be useful to rush-build some of the necessary improvements, especially if the cost is only double, needing Michelangelo's Chapel.
You want to be friends with all other nations (but not allies), having them do the research and trade what they discover. Try not to discover much yourself during the early part of the game, instead focus on a cash/wonders based economy — Research gets expensive twice as fast if you make the discoveries yourself.
You want a hybrid of big and small cities. Small cities don't have much in way of buildings, they generate settlers if there is a food surplus or military/transport units if there isn't. Your big cities also generate settlers when they can't grow any more. If you have a poor start position, your smallest cities may be size 2 with only production and no town center.
Libraries are very expensive (3 gold per turn), so aren't worth it until your city size is high enough to produce 7 or more research per turn. Marketplaces at 1 gold can make more sense, since others are doing research for you, and cash helps speed build crucial wonders and other units or city improvement. Michelangelo's Chapel is a good wonder to have.
Mapmaking and navigation are also useful, especially if you get a poor "small island in Arctic or Antarctic" starting position. You may have to research these fully yourself because continental nations will be less likely to research them. Your ships will be both looking for other nations and transporting settlers to build cities in good spots all over the world.
Monarchy is a good advance to have. It is easy to get and good for having a large, growing empire; research will improve once the Newton's College wonder is built.
With monarchy or despotism, it is good to have some ultra-cheap units, such as sails to transport only one unit, and military units with only defense (perhaps using the "Overweight" Unit Special Feature for maximum strength, but such units cost more to build and maintain; it needs Bridge Building). Other units will be more expensive and focused on attack such as enemy ship killers and movement to attack ground units. If you see buildup of forces at your border, be prepared for that nation to suddenly turn against you and attack in waves. The standard AI will tend to target the same cities in the same way, so you trench in with ship-killer/fort/city walls in their attack path, then press attack when you have enough force to defeat the AI.