What about giving the AI a special tech tree? The AI starts out with an extra technology unavailable to humans, and then that tech, along with others throughout the game is a pre-requisite to more techs, equally unavailable to human players. Those techs could enable units, improvements, and Wonders that are not available to the humans.
How:
In DiffDB.txt you can list the technologies that each player can get, along with the probability. So make the lowest one on the list be the AI tech:
Example: Hard:
Humans can get 3 free techs at game start
AIs can get 5 free techs
Tech list:
General start tech 100%
General start tech 100%
General start tech 100%
AI only tech 100%
other techs 30%
other techs 15%, etc...
This way, the human will always get the first three, and the AI will always get the 4th.
Problems: tech trades, tech diffusion, tech for city conquest, goody ruins, and Great-Library free techs...
There may be a SLIC solution - at the start of every turn, check the human player's list of current techs and delete any of the "forbidden" techs, units, and improvements?
How:
In DiffDB.txt you can list the technologies that each player can get, along with the probability. So make the lowest one on the list be the AI tech:
Example: Hard:
Humans can get 3 free techs at game start
AIs can get 5 free techs
Tech list:
General start tech 100%
General start tech 100%
General start tech 100%
AI only tech 100%
other techs 30%
other techs 15%, etc...
This way, the human will always get the first three, and the AI will always get the 4th.
Problems: tech trades, tech diffusion, tech for city conquest, goody ruins, and Great-Library free techs...
There may be a SLIC solution - at the start of every turn, check the human player's list of current techs and delete any of the "forbidden" techs, units, and improvements?