A thought about resources...

[Khopesh Sidearm]

Don't know if anyone posted this suggestion, and perhaps I'll come to regret it myself but...
What if sometimes some of the natural resources on a map were to run dry? For instance, a vein of marble (does it come in veins?) or an iron ore deposit could be used up, forcing the administrator to move the industry to another parts of the map. These things did happen, and I believe did doom certain cities here in the real world. Might be an interesting extra worry, forcing us CB-ers to make sure our economies aren't one trick ponies or anything. Or make the possibility of running out of a resource increase with the amounts of industry working with that resource (in other words, don't get too greedy).
Again, sorry if someone has already thought of this - I haven't had time to read all the suggestions...

[prof786]

sure over production is possible. but it didn't happen because the demand of goods was minute (overall) compared to the abundant supply. there was no mass production in ancient rome or overfishing or overgrazing or overmining and stuff like that as it is today.

[Thucydides]

I like the idea of resource limits, forcing one to plan for sustainable development. This is not a new idea. In the AoE games, for example, one's tree resources were limited.

However getting the play balance right would be important as I imagine fixed resources could penalise those players that prefer to conservatively build solid cities before tackling military objectives. Fixed resources could also play an unwelcome limit to city expansion in sandbox mode.

[Thucydides]

sure over production is possible. but it didn't happen because the demand of goods was minute (overall) compared to the abundant supply. there was no mass production in ancient rome or overfishing or overgrazing or overmining and stuff like that as it is today.

Humans have always had a large impact on the land, even before formal agriculture. The same for the Romans, who did 'engineer' their environment. In any Caesar-type map if realistic, humans would have had a major impact on the environment, leading to a shift in species and land use types. A simple example, cats were not prevalent in Britain before the Romans came, and when introduced would have had a significant impact on local birds. Another example is the clearing of woodlands for agriculture, which results in a tremendous impact on the environment.