Research and taxEdit
At 4000 BC, increase research (F10) up to 100% because you have no need of cash at this stage. Keep research as high as possible as long as your nation is not too short of money (and you may want extra cash reserves if you are in a war).
Allow for swapping research with friendsEdit
Unless you plan to talk to nobody but to attack every other nation, consider the effect of technology swaps. Right at the start, expect that your first friend will be likely (and very likely if he or she is the standard AI) to have researched The Wheel and Warrior Code and to be willing to swap them for anything else you have. Alphabet and Map Making and Ceremonial Burial might be the best first three for you to research. Later you will extend that idea so as generally not to start researching anything you can see someone else has started: start something different and you will both gain from the resulting swap.
Desirable earliest advancesEdit
Fairly early, research The Wheel to add trade to many tiles that have roads and therefore research faster. However, as noted above, consider not starting The Wheel until you have half of the research done by a friend who has swapped.
Next (subject to the above qualification) you should research Warrior Code to allow you to research new, faster and/or stronger, ground units, and to build a Barracks to make units stronger or heal faster.
Then you have a choice of protective measures (though you can usually research both before needing to use either):
- 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; it is usually the third research tackled by the standard AI
- Bronze Working for stronger (though more costly) weapons and armor modules
See Ground unit (C-evo) for more detail of early ground units.
However, other nations are also at a fairly primitive stage. They will be very unlikely to build military units that can reach your capital and damage it if you keep a militia or (better) a Town Guard in it. AI nations tend to research in this order: The Wheel, Warrior Code, Horseback Riding. The Wheel is of such value that you should not delay it long once you complete roads on your plains and grassland. The other two, however, are also likely to be available by swapping with one of the first nations you contact, as noted in the previous section.
A workable strategy could therefore avoid the military options for a while and develop other advances so that you may eventually get a free "half" research of maybe The Wheel and definitely Warrior Code, Horseback Riding, and later Bronze Working. So the Alphabet > Map Making > Masonry sequence could be the best to follow near the start.
Dual-purpose "Map Making" advanceEdit
A valuable advance if you have any rivers in a city radius, even if you have no port city from which you could launch ships, is Map Making, because it adds a trade point to any river tile you are using. It requires Alphabet.
If, by the time you have three or four advances, you can see that you are on an island with nobody else on it, there's no hurry to build strong defensive units and you can concentrate on ships to check out more coastal water tiles and maybe land a militia or two on other islands or continents. But don't build many Longboats; first be sure that they can reach other useful land; and note that ships you design will all be faster than Longboats. If you are completely isolated you will need Navigation, and it is good if you can research Engineering (preferably before researching Gunpowder) because that adds to your new ships' capacity at no extra cost.
Have your original settler add irrigation and roads: initially roads on grassland and roads and irrigation on plains, later on prairies if your city size is enough to use them. Irrigating plains is top priority if you have grassland being worked, because that will switch a worker from grassland (3 food plus 1 or 2 trade) to an irrigated plain (adding 1 material to the 3 food plus 1 or 2 trade).
Check which flat-land tiles you are currently using, and try to improve them first, with roads, for extra trade after The Wheel is researched, and irrigation of plains for faster growth. Irrigating prairie should be well down the list. Random games seldom require you to use prairies early.
You cannot build roads on rivers initially. (It needs the "Bridge Building" advance and costs a lot of time.)
Roads for movement usually come after "trade-production" roads. Hills, though at double the flat-land cost and with no trade benefit, are quite OK for roads, because you will later give them mines and railroads at no extra cost and you may want quick access to them for placement of defenders. However, forests and jungles and swamps should be avoided unless you are sure that you will never want them cleared, because their roading costs much less after clearance.
Your initial settler belongs to no city and is therefore not costing you food or potentially reducing material resources; it therefore makes sense to keep it for development until Engineers are available and to build new settlers soon to create new cities. AI players often build a city with their first settler quite early and gain an apparent advantage, but it may be short-lived.
Other units and buildingsEdit
The first thing you build could be the Town Guard, which defends against hostile militia and gives you extra happiness to allow more growth. The game will start with you building that, but you can change it immediately.
However, because really dangerous enemies are unlikely to appear in the first dozen turns, you might be better to start with a militia, or two or three or four, for temporary defence then exploration. They will effectively cost less if built before the Town Guard, because the latter takes one material resource for maintenance. Keep one militia in your city until replaced, and send all militia out exploring as soon as the city has an alternative defender or two. Unless you are much constrained by sea and/or friends' territories, it can be good to build three or four militia as fast as possible before the Town Guard. Switch your production accordingly. Then reset it if necessary so that the Town Guard appears on the same turn as your population reaches 5.
The sooner you meet other nations, the more likely it is that they will be friendly, because AI nations tend to have only two or three friends. So send your militia out looking for other nations as soon as possible.
Run exploratory units along rivers to uncover more ground per turn (and note that you can cut corners on rivers for 0.6 movement points; move diagonally otherwise, to see the maximum number of undiscovered tiles (generally 5 per turn but 4 if you have turned at right angles). Climbing mountains temporarily maximizes safety and lets you see more new tiles at first (up to 13) but takes two turns, with little or nothing new to see on the following turn unless it is to another mountain; climbing them should therefore be done only judiciously.
First or second exploration objective is to explore enough to find a reasonably good site for your next city, preferably as close to your capital as it can be, linkable by road, without sharing more than one or two tiles. A site with two or more bonus tiles is highly desirable (and if they are equal distances from it you may get another one or two appearing when you discover Science).
After the Town Guard is built, the next thing you build should probably be a Barracks, followed by a settler or a stronger defender. If you are growing very fast, another Town Guard may be better than either of those, but a Temple (needing Ceremonial Burial) should be on the agenda soon too, for two more morale points at equivalent cost - one tax unit as against one material unit (but Temples are maintenance-free if you have the Oracle Wonder). The medium-term advantage of a temple is that it keeps working when you become a monarchy whereas the Town Guards lose their policing function.
See C-evo advances affecting units/ground for details of how to create appropriate new units efficiently.