I stayed vague in the OP, and concentrated on theory. (every word is important) This seems the best way in order to have a discussion, because everything is opened and calls for everybody imagination if the OP is inspiring enough. But, I failed to transmit some important ideas by detailing them in some OP. I probably didn't have a precise enough idea of them, thus failed to describe them in a seductive way.
But, I would argue, that opened discussion by allowing for the interaction among the posts to 'finalize' or expand the definitions. Overall, I think you started a great thread.
One idea I have a precise idea of and however apparently failed to transmit is the 'civ crucible' : you have a lot of civs at start, and no one is guaranteed to survive because everything moves constantly, by culture mainly ('far' away cities and conquered cities are highly susceptible to defect culturally). There would be means to delay an implosion, and important ones like roads, but ideally big empires would fall soon or later. That would make for a more dynamic game but one would have to adapt the victory conditions, because theoretically you would be limited by a small empire or even doomed in the long run. You also may have to create another way to play, a transitive one, the one when you have 0 cities. (it could even transform into the main screen)
That's practically the main idea i wish i can deliver nowadays, with the one on factions choice maybe, which is totally different, and could imply Social Policies.
Right now, the Civ victory conditions are all Absolutes. You have to come in First at something, everyone else has to lose. I would like to see an option for a 'self-defined' Victory Condition, or a 'non-zero sum' victory, in which your victory does NOT imply that anyone else 'lost'. For instance, I've played a game (as America) in which my sole personal 'victory condition' was to build a railroad from one shore of a Pangaea continent to the other. Official? No, but satisfying to me (I'd just finished reading Ambrose's book on the building of the transcontinental railroad!). Another, more easily defined victory might be to maintain your population's Average Total Happiness (Avg Happy value x turns) above all others. A laudable goal in a ruler, and one that does not require you to build 'Tall' or 'Wide' or in fact, necessarily conflict with anyone else in the game. In a game spanning 6000 years, it always has seemed peculiar that the victory conditions do not allow and reward more different styles of game.
Yesterday I watched a documentary about sand as a resource. It's nearly the same as iron, except that sand sources may have totally disappear in the next decades among with a quantity of islands (and a lot have already disappeared), and beaches around the whole globe, along with their affiliated economy. The thing is that one can't use deserts sand, because its grains are too much eroded by the wind and thus too round, unfit to constructions or territory expansions. Only the beach/ocean sand is valid. The worldwide market of sand is of about 80 billions dollars per year ! There is many transfers... could be interesting for Civ.
Ah, but then where do you stop? I live a few miles from an old gravel quarry, of which there are several in the Puget Sound area. Gravel? It's just crushed rock, right? Well, it has to be the right type of rock, and crushed uniformly, and in fact it is not easily come by and is a vital component for concrete and roadbeds and all kinds of modern engineering necessities. And in parts of the world, potable water is in desperately short supply. The Roman world's access to volcanic ash from areas of the Mediterranean like Vesuvius, Etna and Santorini gave them access to cement, a waterproof building material they used to great effect in their (for the time) innovative engineering. Molybdenum, Nickel and Chromium are necessary component alloy materials to turn steel into armor plate: do we require at least one of them to build any modern tanks or battleships?
Unfortunately, you have to make a decision to limit yourself, or you end up playing something that more resembles the Strategic Bombing Survey of WWII (which identified, I believe, about 55 'strategic' materials to be attacked to cripple Germany's industry) than a playable game.
About copper, it's odd that it's a luxury resource at start. Granted, it has been used for jewelry, but also for weapons. It has been of two significant uses early. why not allow such a duplicity ingame ?
Excellent point: the game has and does artificially designate resources as Strategic, Luxury or Bonus, when in fact they may be several at once or change from one usage to another in the course of the game. Copper is a good point: a vital component to Bronze, the first 'strategic' metal in history and the game, but also a component of jewelry (but not the most important, and certainly not a necessity), and much later, a necessary requirement to get any use out of the discovery of electricity and the applications (electric-motored mass transit, telegraph, telephone, radio, lighting, television and all the Mass Culture that follow) that follow from it.
I could argue that Cattle are a Strategic Resource, in that they provided leather for light armor and sinews and bone and horn for Composite Bows! We've already covered the variable uses of horses, but you could do the same for almost every Resource currently in the game.
I would love to see the game both simplified and made more dynamic by simply having Resources whose application and use changes as your technology (and possibly Social Policy or Religious Practices) change. Cattle provide Bonuses for Food, Production (leather belting for drive trains was a major requirement in the late Industrial period: one steam engine driving power through the belts to dozens of machine tools!), and military units (Horse Archers, Composite Bows) BUT Bison and Deer can also provide the same bonuses (Bison leather was actually preferred for the big industrial drive belts). Copper, as mentioned, is all at once Luxury, Production Bonus, Military, and later Technological Requirement - but can be substituted by numerous other Resources as a Luxury good, and even as a Military - Obsidian (from Volcanoes) can provide equally sharp, though short, blades and cutting edges, and quilted leather or canvas/cloth armor is almost as effective protection as bronze (contrary to popular belief, the Greek Hoplite rarely wore metal body armor by the Classical Period, but relied on his big wooden shield and cloth or canvas cuirass - Alexander's phalanx didn't start wearing metal body armor until after his Indian Campaign!).
Let's open up the Resources - it will also open up trade as you will have to dicker with others to find or substitute resources for all kinds of reasons...
