While I realise it will probably be a long time before any changes to the current era system are considered, since the subject has been raised I feel I might as well relay some of my thinking on the matter;
I think there is no need to insert a new Neolithic Era between Prehistoric/Paleolithic and Ancient- instead, I think much of what is currently Ancient (say, x19-x27) should be relabeled Neolithic, and the remainder of Ancient merged with Classical into a new era called Ancient, which would represent (on our Old World, obviously even on an Earth map things could go radically differently; the important thing is not the time span, but the level of "technology") the time between the invention of writing and bronze metallurgy and the fall of the Western Roman Empire (c. 3000 BC-c. 500 AD). Other Earth civilizations I would consider to be at that level would include (but certainly not be limited to) the Mesoamerican and Inca civilizations, China from the Xia through Han dynasties, India from the Indus Valley Civilization through the Gupta Empire, and Japan from the Yayoi through Heian periods.
I would disagree with the notion of dropping Medieval and Renaissance (and for that matter, with the notion that real-life Classical antiquity was a time of uniform progress and the Middle Ages a time of superstition, stagnation and backwardness, but that's another discussion); historians today still classify Old World civilizations as "Postclassical" (their term for medieval; why it's called postclassical when their universal system lacks a classical, I don't know), and it's hardly as if no technological or social developments happened in China between the Qin and Ming dynasties. One example would be that I heard that China was that at some point (I think it was during the Tang dynasty) on the verge of a proto-industrial revolution that was actually shut down by the Emperor, fearing the effect of widespread ownership of weapons on his rule).
Furthermore, many of the ideas found in Industrial are built upon Renaissance technologies and social capital; the scientific method, Newtonian physics and calculus being a few examples. Furthermore, warfare in this period was very much distinct from medieval and post-Napoleonic warfare; the former used iron and sometimes steel melee weaponry as the primary weapon of choice for both grunts and elites of various kinds, and had a much heavier emphasis on armour, and the latter radically altered warfare altogether by bringing an end to thousands of years of open field warfare through artillery and the machine gun.
My current thinking (which is oriented around constructing an era plan that is as non-culturally specific as possible and gives equal playtime to each era (though that's a matter of turns aimed for per era rather than what eras go in) is this;
- Paleolithic Era (replaces Prehistoric in its entirety, and corresponds in our timeline (OTL) with humanity at any point prior to at least 10,000 BC. I would also consider the Khoisan bushmen and Australian aborigines to have been at this level prior to European contact.)
- Neolithic Era (as mentioned above, replaces x19-x27, and corresponds in OTL with 10,000-3000 BC (Egypt, India, Mesopotamia, the Levant, and Crete), 2000 BC (China), 1500 BC (Greece), 800 BC (the rest of Europe), and 1500 BC (the Americas). I would also consider the tribal natives of the Americas (be they Inuit, First Nations, Native American, Carib, Amazonian etc.) to be at this level, outside of the Mound Builders/Mississippi culture and perhaps some particularly advanced tribal nations such as the Iroquois, as well as most indigenous peoples such as the Zulu, the Maori, Papuans and many (though not all) other Polynesians and so forth)
- Ancient Era (discussed above, so I won't repeat it)
- Postclassical Era (discussed above, so I won't repeat it)
- Early Modern Era (replaces Renaissance in its entirety, at this point I'll only note European events since it seems to be that all other civilizations have basically acquired tech from this era from Europe, rather than developing it independently. It would start with the spread of the Renaissance beyond Italy (and its further development within), the Reformation, the discovery of the New World, the invention of the non-cannon handheld gunpowder weaponry, and the invention of the printing press.)
- Late Modern Era (replaces Industrial in its entirety; from either the beginning of the Age of Revolution with the American and French Revolutions or the Congress of Vienna until either the death of Queen Victoria or the outbreak of WWI.)
- [Name undecided, at least one of these could be Early Contemporary or something along those lines.] (replaces x71-74 (obviously, expansion would be needed to make this into a fully fledged era), represents the time between the death of Queen Victoria or outbreak of WWI until the beginning of the Roaring Twenties (1925).)
- [Name undecided, at least one of these could be Early Contemporary or something along those lines.] (replaces x75-76 (see above), represents the time between the beginning of the Roaring Twenties and the end of World War II, foundation of the United Nations and beginning of the Cold War.
- Middle Contemporary/Atomic Era (Cold War)
- Late Contemporary/Information Era (End of the Cold War and invention of the Internet until (fairly arbitrarily) around 2050
I have a different approach to the future than pepper2000, one which basically divides it in to the Near Future Era (2050-2200, futuristic but still confined to Earth and maybe the Moon and Mars), and the Far Future Era (2200-3000, when the human race, to apocryphically quote former US Vice President Dan Quayle, begins to enter the Solar System and eventually expands to the local stellar neighbourhood. However, I don't think there's any chance of that ever being the mod's scheme outside of my modmod.
I post this mainly for Misanthropia's benefit, as I realize it will be a long time before the question of eras becomes feasible to raise again, and I've made the other team members aware of my ideas several times before.
So much eras are not in this game. Why have Sid Meyer don´t hire you to create civ 5 and 6 ? I hate it in civ 5 that you can have only one unit on a tile and city, that makes the game much more boring and in civ 6 should a whole citytile be for a world wonder ? This sucks. Civ 4 was the best game that was every programmed in the civilizationsessions and with your mod it is the brilliatest game ever was programmed by human beiings on this planet ! Since your mod this game is my absolute favorite game and I am addicted to it ! 