I have some thumb-rules then it comes to how AI-units should behave. AI-units must know how to respond cleverly against threats directly next to them - only 1-2 square away. Im certainly not asking for the "Holy Grail" here - I dont expect huge & cleverly coordinated D-day invasions launched from the other side of the world. Just below:
- If the attack-power of invading AI-units/armies is substantially weaker then any HP-city defence-power - then the AI-invaders should always concentrate on pillaging city-areas only, and HP-roads between city-areas. No more hopeless AI-attacks on HP-cities. Ancient/medieval AI-units should almost never attack HP-cities guarded by modern units - instead they almost always concentrate on pillaging...
- If the attack-power of a free-roaming military AI-units/armies is substantially weaker then the defence-power of enemy HP-units/armies - then the AI should avoid making use of its turn by launching fruitless attacks. Instead they should either fortify within its own cities, or (if within enemy HP-territory) fortify on the nearest high-defence terrain-tile; preferbly a mountain.
- If the attack-power of invading HP-units/armies is substantially stronger then the AI-city defending units, then these units should always stay within its city-walls, either lashing out preemptive strikes against any HP-units directly outside its cities; or simply stay fortified. Two or more conquered cities within a certain amount of turns, is interpreted as "full scale invasion", and all the remaining AI-cities production switch automatically to military priorities only.
Well, above is for starters. Feel free to comment or add more AI-unit thumb-rules.
