You're right that it's a goal, and varies over time. In a conquest game my initial build order is scout/scout/worker or scout/scout/warrior. I then add archers and spears to capture the first city:
- 3 archers
- 2 spearmen
- 2 scouts
The 2nd city captured usually has walls:
- 2 catapults
- 3 archers
- 2 spearmen
- 2 scouts
After that I add the strategic units for early-medieval warfare:
- 3 swordsmen
- 2 chariots
- 1 horsemen
- 2 catapults
- 3 archers
- 2 spearmen
- 2 scouts
Once ready to upgrade to medieval units at least three or four cities are conquered. I often stop a while at this point to let happiness catch up.
Something Sid pointed out is techs usually alternate between strong and weak ones. Philosophy is strong, Theocracy is weaker, then Education is strong again. Variety makes the game interesting. All three leading to Scientific Method are powerful, and SM leads to two powerful techs.
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What we can do with the current start bias system is very limited. However, it's all in the part of the code we have access to... so we can change it or replace it completely. For a while now I've been intending to revamp civilization placement.
With the current method each territory on the map gets rated based on which terrain type is most abundant (grassland, hills, forests, etc). The game then places civs in this order:
- Those who need
adjacent to coast
- Need
adjacent to river
- Need specific terrain abundance(s)
- Avoid specific terrain abundance(s)
One big problem is the current system cannot weigh factors like:
- Natural wonders for Spain
- Mountains for Inca
- Lakes for Aztecs
- Iron for Rome
- Citystates for Greece/Siam/Mongolia
- Coastlines for Polynesia. It only checks if the capital is adjacent to coast, even if it's a tiny 5-tile sea.
- etc...
The other problem is this situation:
- Elizabeth - Coastal leader who doesn't care what terrain she's placed on.
- Hiawatha - Forests are essential.
- 2 coastal territories, 1 of which is coastal AND the best forest.
Elizabeth might be placed in the ideal forest spot and the current system just moves on... messing up Hiawatha. Or if we reverse them Elizabeth might not get a coastal territory. What we need is to
compare and rank all the leader's priorities before placing them.