Freeciv could be a very challenging game to beat due to its complexity (still simple compared to Civilization III). The way to beat almost any of the Civilization games is to know its loopholes. With the loopholes, you are sure to beat the game.

Configuration

Your first task is to setup the server. Use generator 2 since you'll have your own island that is a decent size. Also, use 3-4 computer players. If you have too few, it's easier for the computer to dominate. Also, set the players to hard. Yes, hard. If they're easy, then they will attack earlier, before you get a chance to build up your forces. Hard will make them attack much later. Lastly, set huts to 0 to avoid randomness in technology advances.

Starting

Build a city your first or second turn. Use all your settlers to build cities until your island is full. Each city should have 3-4 spaces in between it. One of the major loopholes is that larger cities don't help as much as they should. With so many cities, your science should be high.

Speaking of science, make sure your tax rate is at:

  • Science - 60%
  • Luxury - 20%
  • Tax - 20%

In each city, even after your island is full, build settlers. Build build build. Once your island is full, use the settlers to irrigate and build roads. Once you have your roads completed, use them to build railroads, then your units will really move. At the same time, use the Trieme to move your settlers over to other islands and setup a few colonies at the nearest pole.

Technology

Technology is where this strategy happens. You should use the following goals in order: The Republic -> Navigation -> Steam Engine -> Invention -> Communism.

  • The Republic - The Republic lets you move your science tax rate up to 80%, thereby increasing your science production drastically. If that's at 80%, make the other two taxes at 10% each.
  • Navigation - Gives you Copernicus's Observatory and Mapmaking gives you the Lighthouse. Both of these wonders improve your mobility on the seas by 2 moves each turn, each unit. Navigation also gives you Caravels which can end their turn anywhere.
  • Steam Engine - One word: Ironclad. The Ironclad is your basic starting point for your military build-up. Build these like it's nobody's business. Use them to attack coastal cities.
  • Invention - With Leonardo's Workshop, you are guaranteed to keep your military up to date. MW upgrades one obsolete unit per turn. This doesn't sound like a lot, but after 10 turns, half your military is upgraded to the latest and greatest.
  • Communism - While not friendly in the real world's western eyes, Communism will keep your citizens content during war.

After you complete those, discover technology which will upgrade your sea fleet to Cruisers. Your ultimate sea based goal should be Battleships, a 12/12/4 (attack/defense/movement) vehicle. Very little can be done to stop a fleet of veteran battleships.

Ending

Eventually, you will have taken over almost all of the coastal cities. A good strategy for taking over the inland cities is to use Cruise Missiles which are launched from either nearby cities or Aircraft Carriers. Having a lot of Armors for capturing cities is advised since they're strong and fast.

Miscellaneous Notes

I also like to get the Pyramids and Adam Smith's Trading Co. The Pyramids add one Granary to every city. Adam Smith's Trading Co. will make all city improvements that have a cost of 1 free in all cities. This is sure to free up your financial resources.