The Goals file defines the various goals that the AI can pursue. The various goals that are defined within this file can then be set from the Strategies file where they are given priority ratings and other attributes.
This file defines the various Feats that can be accomplished in the game. There are two basic types of Feats and three custom Feats possible in the game. The basic Feats are first nation to discover an Advance and first nation to build X number of buildings. Any number of these basic Feats can be defined.
The three custom Feats (FEAT_SAILED_AROUND_THE_WORLD, FEAT_CONQUERED_BY_FORCE and FEAT_CITY_RECAPTURED) are hard-coded in the game and must exist in the Feat.txt file. The conditions that trigger these Feats cannot be changed without changing the source code though their effects can be changed. New custom Feats can be created and logic for triggering them must be written in SLIC scripts. See the SLIC scripting documentation for more information on how SLIC scripts could be used to trigger Feats.
The Diplomacy SLIC file can be used to define custom SLIC scripts to fine tune AI diplomacy. It also contains SLIC message box definitions for some diplomacy related messages. See the AI Customization document for more information on how to write AI Diplomacy SLIC scripts.