Well 5 cents
Sacking capitals should not give any maps at all. Where does this idea come from that sacking a capital automatically gives maps? Most likely they would never even find maps nor have the idea to look for them in the first place.
Maybe just for game sake, give it 10% chance in sacking a capital, nothing more.
That also makes a good navy better, as that would be the only way to steal maps. I would love this working.
Well of course I know why its there, is so that when at war you can conquered the entire enemy. Well that is not really the problem of the enemy is it? If you cant conquer more then 50%, because you don’t know anymore - well to bad for you !
How can you expect to be able to conquer a nation you don’t even know about????
For those nation that does not have a chance at navies, introduce the option of buying maps, or trading maps for provinces, armies, money, prestige (relation), vassals, alliances and even explores!. Not entirely historical, but a good fun spectrum for the game.
Colonization itself is already fully solvable via the ai files, and introduction of hardcoded ‘blocks’ degrades the very purpose of the ai files themselves. That is not only counter productive, that is too silly.