(Mods, I know, there's no Civ4 Suggestions forum yet, but when there is, feel free to move it there. 
).
Ok, here's my list of things:
Resources -
Strageic[/b]:
Make them limited, even if just on higher difficulty levels. They could be found in other places, but only for a limited time. That way, (like AOE), if you run out of resources, you're stuck with trading, recycled parts, and outdated units. The same goes for the economy. Resources are a major part of it. It would be hard, and expensive if all you had were plants, and dirt. (You could manipulate the atoms with some future techs, though).
In addition, add a "stockpile" option (I read this somewhere on here. I'm just adding to it.). Have a certain amount of it in each city. (Ever take a drive/ride through your city's industrial parks? I did on the way to my grandmother's house on the other side of the city).
Any civ that conquers would acquire that stockpile (which would make a resource that's no longer availible, much more valuble).
Bonus:
Some of these resources are animals and food. If a square gets polluted, these resources should have a chance of disappearing. (Save the Whales!
) - which brings up water pollution... (more on that later) Grazing resources (i.e., cattle) can (if you have road to them) alter the land to plains, and desert. (Think overgrazing). You could have an option to move them.
Luxeries:
Similar to Bonus. If you overuse, they can disapear. (i.e., having 10 cities use one source of spice, too much ivory poaching, and elephants go extinct).
Ocean Luxeries:
Here's a new one. There are some luxeries in the deep sea, (think deep sea drilling). The primary luxeries could be oil, and maybe sand for building new land (which will probably require another future tech). Be creative Firaxis!
Pollution:
Land:
There should be different kinds of pollution. Global wastes (i.e., ozone destroying chemicals), and local (destruction of natural habitat - would only affect squares in the surronding area).
Ocean Pollution:
Mainly oil spills, which can be caused by cities, or ships that are attacked. This would fall into the category of local pollution, but could have global reprecussions. (Too much of any local pollution - leading to loss of animal life) could lead to squares being overrun by deserts, forests, and jungle (what ever happened to swamps?)
Economy (of war):
Trade Routes and battle supplies:
Bring back the caravans/freights. Not only can they be used for trade, but also for supplying armies at war. This can allow civs to intercept war supplies (as well as stealing another civ's trade) and use them for their own use. (i.e., a civ that intercepts rifles, but is still in antiquity, can create only one conscript riflemen unit).
Thus, "The spoils of war".
Also along these lines, units can't stand around forever, say half way around the world, since their supplies are going to dwindle. (due to weapons being broken, age (weapons and people), etc.). Why would it take them 15 turns to get to where they want to go, and only 1 to "resupply" them? That's where the caravans/freights (or "War Wagons) come in.
Plundering and Pillaging:
And I don't just mean improvements. This applies to the stockpile idea. Whenever you defeat a unit, you collect their weapons and ammo. You can either use this to fuel your unit (i.e., if they're running low - provided they have to be trained), or dispatch a caravan/frieght to add to your civ's stockpile, or even trade it to another civ. If you invade a city with barracks, you get half of their weapons stockpile (assuming half were destroyed in the battle).
Ocean Colonies:
Linked to the above ocean resources. Basically, you bring a worker on a boat, and have them "turn into" a drilling rig. (the boat could be the rig, too). You could have automated boats shipping oil back to the mainland.
Other:
"Bridges over troubled waters":
Anyone watch that Discovery Channel/TLC program the other week about future projects? Bridges where one of them. (possibly with a future tech...) You can build a bridge over sea tiles, even one or two ocean tiles. (Civ1 had the right idea! ).
disease:
This is one of the things that can bring a civ down to it's knees, or give it a strenght. The Aztecs where decimated because they had no resistance to smallpox, but the Spanish did. Civs should have a list of diseases and resistances. That way, say Spain contracted smallpox, and now it's a resistance. They go over to Mesoamerica, and their units (workers, explorers, military) inadvertantly gives the Aztecs smallpox.
Another scenario. You build a few colonies in the jungle. A few (population) die off because of disease and the rest become resistant. Your ships are slow enough (say, caravels, galleons) that it allows the colonies to acquire resistance and start building workers. I say slow, since they don't get back to the main area until a few turns (5-10 turns, let's say). They bring reinforcements (troops, workers - some who will still die off due to lack of resistance). Your caravel/galleon picks up a worker and brings him back to your homeland. Any unit that worker passes (even being in a city - it must be on the same square) has a good chance of getting that disease. A city with a high population (say, 12) will fare much worse than a size 2 city). So, if you're not careful, you could fall on your own sword. (Having advances like medicine would stem the problem).
Climate Changes:
This has got to be the trickiest thing to simulate.
The El Nino effect, and "Oceanic conveor belt" (warm and cold water circulation - it was on the Discovery channel or TLC last year) were just discovered. (as well as CO2 recycling - same program - of which I didn't catch most of it at all). And just recently, a program showing the fall of the Maya due to a severe drought. (Ever play SimLife and SimEarth? Of course, adding every system possible would bog the game down!) There could be a simplified version, such as a standard weather pattern that sometimes goes out of wack. To use the Maya example, heavy snows in Europe could have covered much of the roads (making trade routes harder), and in Mesoamerica, their population plummeted. (probalby rioting, revolting, canabilism etc.).
I'll try to think of some more.
).Ok, here's my list of things:
Resources -
Strageic[/b]:
Make them limited, even if just on higher difficulty levels. They could be found in other places, but only for a limited time. That way, (like AOE), if you run out of resources, you're stuck with trading, recycled parts, and outdated units. The same goes for the economy. Resources are a major part of it. It would be hard, and expensive if all you had were plants, and dirt. (You could manipulate the atoms with some future techs, though).
In addition, add a "stockpile" option (I read this somewhere on here. I'm just adding to it.). Have a certain amount of it in each city. (Ever take a drive/ride through your city's industrial parks? I did on the way to my grandmother's house on the other side of the city).
Any civ that conquers would acquire that stockpile (which would make a resource that's no longer availible, much more valuble).Bonus:
Some of these resources are animals and food. If a square gets polluted, these resources should have a chance of disappearing. (Save the Whales!
) - which brings up water pollution... (more on that later) Grazing resources (i.e., cattle) can (if you have road to them) alter the land to plains, and desert. (Think overgrazing). You could have an option to move them.Luxeries:
Similar to Bonus. If you overuse, they can disapear. (i.e., having 10 cities use one source of spice, too much ivory poaching, and elephants go extinct).
Ocean Luxeries:
Here's a new one. There are some luxeries in the deep sea, (think deep sea drilling). The primary luxeries could be oil, and maybe sand for building new land (which will probably require another future tech). Be creative Firaxis!
Pollution:
Land:
There should be different kinds of pollution. Global wastes (i.e., ozone destroying chemicals), and local (destruction of natural habitat - would only affect squares in the surronding area).
Ocean Pollution:
Mainly oil spills, which can be caused by cities, or ships that are attacked. This would fall into the category of local pollution, but could have global reprecussions. (Too much of any local pollution - leading to loss of animal life) could lead to squares being overrun by deserts, forests, and jungle (what ever happened to swamps?)
Economy (of war):
Trade Routes and battle supplies:
Bring back the caravans/freights. Not only can they be used for trade, but also for supplying armies at war. This can allow civs to intercept war supplies (as well as stealing another civ's trade) and use them for their own use. (i.e., a civ that intercepts rifles, but is still in antiquity, can create only one conscript riflemen unit).
Thus, "The spoils of war".
Also along these lines, units can't stand around forever, say half way around the world, since their supplies are going to dwindle. (due to weapons being broken, age (weapons and people), etc.). Why would it take them 15 turns to get to where they want to go, and only 1 to "resupply" them? That's where the caravans/freights (or "War Wagons) come in.
Plundering and Pillaging:
And I don't just mean improvements. This applies to the stockpile idea. Whenever you defeat a unit, you collect their weapons and ammo. You can either use this to fuel your unit (i.e., if they're running low - provided they have to be trained), or dispatch a caravan/frieght to add to your civ's stockpile, or even trade it to another civ. If you invade a city with barracks, you get half of their weapons stockpile (assuming half were destroyed in the battle).
Ocean Colonies:
Linked to the above ocean resources. Basically, you bring a worker on a boat, and have them "turn into" a drilling rig. (the boat could be the rig, too). You could have automated boats shipping oil back to the mainland.
Other:
"Bridges over troubled waters":
Anyone watch that Discovery Channel/TLC program the other week about future projects? Bridges where one of them. (possibly with a future tech...) You can build a bridge over sea tiles, even one or two ocean tiles. (Civ1 had the right idea!
).disease:
This is one of the things that can bring a civ down to it's knees, or give it a strenght. The Aztecs where decimated because they had no resistance to smallpox, but the Spanish did. Civs should have a list of diseases and resistances. That way, say Spain contracted smallpox, and now it's a resistance. They go over to Mesoamerica, and their units (workers, explorers, military) inadvertantly gives the Aztecs smallpox.
Another scenario. You build a few colonies in the jungle. A few (population) die off because of disease and the rest become resistant. Your ships are slow enough (say, caravels, galleons) that it allows the colonies to acquire resistance and start building workers. I say slow, since they don't get back to the main area until a few turns (5-10 turns, let's say). They bring reinforcements (troops, workers - some who will still die off due to lack of resistance). Your caravel/galleon picks up a worker and brings him back to your homeland. Any unit that worker passes (even being in a city - it must be on the same square) has a good chance of getting that disease. A city with a high population (say, 12) will fare much worse than a size 2 city). So, if you're not careful, you could fall on your own sword. (Having advances like medicine would stem the problem).
Climate Changes:
This has got to be the trickiest thing to simulate.
The El Nino effect, and "Oceanic conveor belt" (warm and cold water circulation - it was on the Discovery channel or TLC last year) were just discovered. (as well as CO2 recycling - same program - of which I didn't catch most of it at all). And just recently, a program showing the fall of the Maya due to a severe drought. (Ever play SimLife and SimEarth? Of course, adding every system possible would bog the game down!) There could be a simplified version, such as a standard weather pattern that sometimes goes out of wack. To use the Maya example, heavy snows in Europe could have covered much of the roads (making trade routes harder), and in Mesoamerica, their population plummeted. (probalby rioting, revolting, canabilism etc.).
I'll try to think of some more.
and make strat resources MORE scarce? are you joking?? already in half the games i play theres no coal ANYWHERE, so no RR's for the entire game. they are far too scarce already.
Make it better to give territory back to a country if you are democratic.
), but make units have a stat bonus vs. a unit from a lower era. (i.e., i.e., middle vs antiquity would be +2 on all stats, indust vs antiquity would be +4, and so on). I don't think a band of regular warriors should be very successful against elite modern infantry. 
