Ai will be more aggressive.

Better Ai expansion and defending territory won.

Raised the costs of buildings and tech and unit and upkeep for the player. You will make money ...but spend it wisely.

Adjusted Ai aggression.

Lowered zone of control for land armies.

Trade will be harder to get. But not impossible as it is a key mechanic to keep the ai in the game.

Reconfigured diplomatic ai chance to accept treaties. Changed spotting for more realistic line of sight. Changed religious relations.

Ai more likely to attack settlements.