Modding, short for modifying, refers to editing the game files to customize the player's copy of Civilization II.
Information on default civilization names, titles, and behavior is located in the
Rules.txt file. Instructions on the meaning of the values are provided through comments within the file, assisting its modification.
In particular, partial information is provided for the Arab and Inca civilizations. These civilizations can be added to the game by replacing one of the other 21 playable civilizations in the list above them.