Things You'll Need
Instructions
Locate the editor for your game, it is in the same folder as your executable game file. The default path should be: c:\program files\atari\civilization III\civ3edit.exe. Double click the file to open it.
Select "scenario" then "custom rules" in the editor menu. Hit "OK" on the box that pops up.
Select "rules" then "edit rules" and select the civilizations tab back on menu.
Select "add" and type in your civilization name at the race prompt. Hit "OK."
Add your civilization's name under "noun." For example, America is the name and American for the adjective.
Fill in the default leader name and title. For example: Lincoln, president.
Fill in the city names and great leaders on this same window. You'll want 20 to 40 default city names and at least one great leader.
Fill in the remaining optional information, such as starting technology, civilization strategy, bonuses and other information.
Ignore the "civilopedia" and "animations" entries for now. You can still play the game with the new civilization, but don't search for your civilization in the civilopedia until you add an entry, or it will crash.
Click "close" and go to "file" and then "save" to save your custom civilization. Remember the file name you chose for the next step.
Launch the Civilization III game.
Select "scenario game" and open the scenario you created.