Tips on improving technology?

[Genghis Khaiser]

For example, I have seen people reaching the Global Era before the 1800s. How do they do that?

I can be ahead of everyone with tech buildings and espionage, but not that ahead.

 

[Tigranes]

Maybe they cheat?

Once you are ahead of everyone -- espionage become irrelevant.

Here is my Great Ming China, winning 50+ before the deadline. Already researching American tech -- Representation. Never stole a tech, mostly running more than 50% science, cranking 570 even without National College. Just improved every single tile, every empty tile gets a cottage. Focus on capital, largest city in the world, has Oracle, Ishtar Gates, Grand Canal, Porcelain Tower, Forbidden Palace. Beijing has Terracotta Army and the Great Wall. That's all my army that you see in that picture. After Mongols -- disband every obsolete unit and most Workers until you spend 0 gold (almost 100% inflation after 300 turns from start makes every gold spent double), There is zero need to greet Mongols with Muskets or even Rifles, like some people indicate in Guides. Just a well promoted army of Lancers and Pistoliers will do. They were afraid to declare on me, I did it myself just for fun once 10 turns of peace for new born civ was over. They gave me Russian city as a peace offering, which I used to rush Explorers to contact Europeans. Still running Meritocracy and Merchant Trade, but could have greatly improve things with Regulated Trade, Centralism and Individualism.

 

[Genghis Khaiser]

To summarize, improve every tile but focusing on cottages?

 

[1SDANi]

To summarize, improve every tile but focusing on cottages?

Cottages are insanely good for your economy. Fully matured and with the right civics, they can drive a nation's entire economy by themselves. This is true also in Vanilla Civ 4 and BTS. Basically, Cottages are the lifeblood of every nation with vast stretches of resourceless food providing land's economy. That last point is important, the Greek and Roman peninsulas don't have much land without resources, and so there's few areas to place cottages, and any terrain with 1 or 0 food on it must be backed up with another terrain with 3 or 4 food. In short, your cities will grow best when you do not have a net negative in food. And more citizens means more units to protect your empire.

 

[1SDANi]

Also, be sure to only build the bare essentials in each city. It's much more important to build workers, settlers, and military units than a building that gives little benefit. Here's some buildings and reasons on why you might want to build them:

Spoiler Buildings and Reasons :

Granary/Aqueduct:

• Will you whip often (whipping = rushing using Despotism)
• Will your city grow a lot after the granary is built

Library:

• Are you focusing on science and your city produces a lot of commerce
• Does your city have a lot of excess food and you want a Great Scientist
• Are you running Republic and you want a Great Scientist

Market (Most of the time is not essential, but putting this here for civs like Rome and Mali):

• Are you focusing on gold and your city produces a lot of commerce (Most players won't focus on gold enough for this to be useful in my experience)
• Does your city have a lot of excess food and you want a Great Merchant
  
• Are you running Republic and you want a Great Merchant

Theater:

• Are you focusing on culture and your city produces a lot of commerce
• Do you not have access to a religion and want to give a new city it's BFC
  
• Does your city have a lot of excess food and you want a Great Artist
  
• Are you running Republic and you want a Great Artist

Forge:

• Does your city output a lot of production
• Does your city have a lot of excess food and you want a Great Engineer
  
• Are you running Republic and you want a Great Engineer

Jail/Courthouse:

• Are you teetering on instability? (They increase stability by 1 each)
• Are you focusing on Espionage?

Barracks:

• Will you build a lot of military units

Stable:

• Do you already have a Barracks and will build a lot of Cavalry

Health Buildings:

• Is your city's unhealthiness drastically reducing growth time

Religion Buildings:

• Are you planning on building a +yield religious building wonder
• Temple:
  • Is your city unhappy
    Are you focusing on culture (The Cathedrals increase culture by a lot)
• Monastery:
  • Do you have the Holy City (+1 Gold per city following the religion is really good)
  • Are you teetering on instability (Religious Unity is powerful)
  • Do you want your cities to expand their borders quickly (+1 Culture means they gain a BFC in 10 turns AKA you don't need to build culture buildings for it)
  • Is many of your cities unhappy (State Religion increases happiness by 1)

Those are the main necessary buildings for early game, not sure about late game. I've only played it a couple of times. In short, build what is absolutely needed and then pump out workers, settlers, soldiers, and any other buildings you unlock along the way that you absolutely need. You'll get a feel for what you can do without as you play.