Just trying immortal difficulty using Persia immortal 
rush. Easily crush Bismarck, leave his last city to practice swords and to extort tech. Because there is a stone near capital, build pyramids, then later great lighthouse and collosus. If there is only Germany on this continent, thing is done. However, Elizabeth is also there, and they quickly get longbow before I capture Berlin. 
My main finding is that there is a race between tech advance and bankruptcy. If I build too many cities too early, city maintenance will eat too much of economics and kill reserach. What limits our civ most is often not production, but research. Human easily becomes the No. 1 or 2 in production, but it's very hard to be tech advanced. Therefore, some thoughts:
1. Great lighthouse is very useful. Just 200 hammers, add 2 trade routes to each coastal city. When you can only make 20-30 beaker per turn, this advantage is huge.
2. Learn currency asap. One more trade route to each city, and able to build market, very helpful. A new coastal city can immediately get 4 trade routes, therefore make up for a large portion of the maintenance burden it adds to the civ.
3. Reduce unit support if possible. Unit support is what you pay for having units outside territory. Therefore, if you want to explore, better use fast movers. If want to attack a city, better gather forces inside border then send them together, rather than letting some units stand outside and waste unit support.
4. Build all the available infrastructures in most cities. Well, this is obvious.
5. Don't count on alphabet and tech trade. Often you don't have many or any tech to trade, and AI doesn't want to trade first hand tech to you. So better improve the research ability of your own civ.
6. Fight barbarians and take their city if it's in a good position. The cash and XP gain in this way is admirable.
7. Be careful about building new city. When you have a number of cities, a new one adds around 10 gold to city upkeep, which is a great burden in early ages. My basic idea is to avoid building new city unless: A. It's coastal (4 trade routes) and captures some resource; or B. It's inland but captures some resource, and is a natural connection to your new barb or coastal cities; or C. When you can easily afford the upkeep, -- but that's quite late.
rush. Easily crush Bismarck, leave his last city to practice swords and to extort tech. Because there is a stone near capital, build pyramids, then later great lighthouse and collosus. If there is only Germany on this continent, thing is done. However, Elizabeth is also there, and they quickly get longbow before I capture Berlin. My main finding is that there is a race between tech advance and bankruptcy. If I build too many cities too early, city maintenance will eat too much of economics and kill reserach. What limits our civ most is often not production, but research. Human easily becomes the No. 1 or 2 in production, but it's very hard to be tech advanced. Therefore, some thoughts:
1. Great lighthouse is very useful. Just 200 hammers, add 2 trade routes to each coastal city. When you can only make 20-30 beaker per turn, this advantage is huge.
2. Learn currency asap. One more trade route to each city, and able to build market, very helpful. A new coastal city can immediately get 4 trade routes, therefore make up for a large portion of the maintenance burden it adds to the civ.
3. Reduce unit support if possible. Unit support is what you pay for having units outside territory. Therefore, if you want to explore, better use fast movers. If want to attack a city, better gather forces inside border then send them together, rather than letting some units stand outside and waste unit support.
4. Build all the available infrastructures in most cities. Well, this is obvious.
5. Don't count on alphabet and tech trade. Often you don't have many or any tech to trade, and AI doesn't want to trade first hand tech to you. So better improve the research ability of your own civ.
6. Fight barbarians and take their city if it's in a good position. The cash and XP gain in this way is admirable.
7. Be careful about building new city. When you have a number of cities, a new one adds around 10 gold to city upkeep, which is a great burden in early ages. My basic idea is to avoid building new city unless: A. It's coastal (4 trade routes) and captures some resource; or B. It's inland but captures some resource, and is a natural connection to your new barb or coastal cities; or C. When you can easily afford the upkeep, -- but that's quite late.
