Prevent AI from using Venice

Solution 1:

Out of the box, there is no way to blacklist certain civilisations.

Your best options are:

• Selecting the civilisations manually as you note, using the in-game Advanced Setup feature.

• Using the Really Advanced Setup Mod, which allows you to disable civilisations one by one, as well as a number of other setup options (starting biases, units, terrains etc.)

• Manually disabling the civilisations you do not want to be selectable, in the game config files.

To manually disable the civilisations open the config file "Civ5Civilizations.xml" in a text editor. Find the civilisation you do not want to be selectable (Venice) and add the xml line <AIPlayable>false</AIPlayable>. This will disable the AI's ability to select that nation.

Of course, regular disclaimer that using mods, or manually editing game files is at your own risk.