As it currently stands, the Great Wall doesn't make much sense in how it automatically expands along with your expanding cultural borders. Plus, rushing for the Great Wall as a strategy can be sort of an easy early-game buzzkill in many situations (half of the fun in the early game is fighting barbs. If the GW only somewhat mitigated the barb threat so that they are easier to deal with, then that would be more fun). Here are some suggestions for making the Great Wall more fun:
1. Have the Great Wall (both in its barb defense and in its GG bonus) only automatically apply to the tiles that it originally enclosed. Make this a fixed geographic area for the entire game (see below for possible mechanisms to make it more powerful to compensate).
2. Or, have the same as above, but in order to expand the Great Wall as your cultural borders continue expanding, have the GW open up another build item called, "Expand Great Wall" or something, for a cheap cost (1 hammer per additional tile on normal speed, for instance). This would add more wall graphics in addition to the original wall graphic on the map (so that the GW in the game would look like the actual Great Wall of China--not one efficient line, but layers of confused additions over the centures), and the effects (barb defense + GG bonus) would likewise expand. You could build these additions as many times as you wanted throughout the game. This would give an incentive to wait to finish the original GW until key border pops because that gives you added free protection. It would be a fun balancing act. "Hmm, do I play it safe and finish it now, or try my luck and wait 2 turns after my capital will have its 2nd border pop?..."
To compensate for the reduced effect/added cost...consider any combination of the following:
A). Make the Great Wall function as a terrain feature similar to a river (attempted attack across it gives +25% to defender), albeit one that amphibious promotions don't negate, and one that can only benefit the player who owns the GW (attacking an incoming invader across your own GW will not give you a 25% penalty because it is assumed that your people are manning the wall).
B). Make it so when you build a city along the Great Wall (in the same way that you'd build along a river), that city gets an extra +1 happiness for "We appreciate our military protection" or whatever.
C). Make it so that any opposing unit crossing the Great Wall thereby uses up all of its movement points for the turn. (Would simulate how China used the wall to slow down the incoming Mongol horsemen).
D). Remove the hard-and-fast assured protection against barbarians (which is kind of unrealistic), but make it so the Great Wall automatically inflicts X hitpoints of damage to any (pre-gunpowder or pre-rifling) opposing unit that is crossing over the Great Wall (barbarian or foreign civ alike) within your cultural borders. Say, 25% damage. That means, units with more than 75% damage cannot cross over the GW at all without dying (so they must stop and heal first), and that units will have to stop and heal after crossing the wall or risk taking on your cities with 25% damage. Note: make this even applicable to when the enemy units are retreating and crossing back over the GW. (But of course it would not be applicable to your own units).
I feel that any combination of these changes would make the Great Wall both more realistic in the game and more nuanced and fun.
1. Have the Great Wall (both in its barb defense and in its GG bonus) only automatically apply to the tiles that it originally enclosed. Make this a fixed geographic area for the entire game (see below for possible mechanisms to make it more powerful to compensate).
2. Or, have the same as above, but in order to expand the Great Wall as your cultural borders continue expanding, have the GW open up another build item called, "Expand Great Wall" or something, for a cheap cost (1 hammer per additional tile on normal speed, for instance). This would add more wall graphics in addition to the original wall graphic on the map (so that the GW in the game would look like the actual Great Wall of China--not one efficient line, but layers of confused additions over the centures), and the effects (barb defense + GG bonus) would likewise expand. You could build these additions as many times as you wanted throughout the game. This would give an incentive to wait to finish the original GW until key border pops because that gives you added free protection. It would be a fun balancing act. "Hmm, do I play it safe and finish it now, or try my luck and wait 2 turns after my capital will have its 2nd border pop?..."
To compensate for the reduced effect/added cost...consider any combination of the following:
A). Make the Great Wall function as a terrain feature similar to a river (attempted attack across it gives +25% to defender), albeit one that amphibious promotions don't negate, and one that can only benefit the player who owns the GW (attacking an incoming invader across your own GW will not give you a 25% penalty because it is assumed that your people are manning the wall).
B). Make it so when you build a city along the Great Wall (in the same way that you'd build along a river), that city gets an extra +1 happiness for "We appreciate our military protection" or whatever.
C). Make it so that any opposing unit crossing the Great Wall thereby uses up all of its movement points for the turn. (Would simulate how China used the wall to slow down the incoming Mongol horsemen).
D). Remove the hard-and-fast assured protection against barbarians (which is kind of unrealistic), but make it so the Great Wall automatically inflicts X hitpoints of damage to any (pre-gunpowder or pre-rifling) opposing unit that is crossing over the Great Wall (barbarian or foreign civ alike) within your cultural borders. Say, 25% damage. That means, units with more than 75% damage cannot cross over the GW at all without dying (so they must stop and heal first), and that units will have to stop and heal after crossing the wall or risk taking on your cities with 25% damage. Note: make this even applicable to when the enemy units are retreating and crossing back over the GW. (But of course it would not be applicable to your own units).
I feel that any combination of these changes would make the Great Wall both more realistic in the game and more nuanced and fun.
). 
, farms lose 1 
, etc. You could then remove the fort with workers to allow it to continue as before. But I would also like forts to be better than they are now. Strengthening defenders is one way to make military victory a harder proposition.
from walls
