This community wiki is meant to be edited by one and all. As you edit, please remember that we are trying to come up with a list of terms that make sense to worldbuilding, not Earthlings (or, specifically, Americans. I hope my brothers and sisters understand what I mean). The goal of this project is to create a series of eras/ages that are defined by advancing technological and cultural achievements - not simply the timeline of Earth. This is especially problematic with the medieval era.
These era classifications are for the purpose of defining predictable technological and cultural references for the purpose of worldbuilding. Because different areas of the Earth developed at vastly different rates (often resulting in regional "eras"), the eras defined below may not conform directly to Earth history.
As you edit, please pay attention to how I've formatted things and try to keep that formatting. Organization is our friend.
I am not married to the syntax of the tag names. Their primary purpose here is both ease-of-use and recognizability.
Just to beat a dead horse, when you look at these, please remember to take your nationalist-glasses off. I found it a real challenge to look past my U.S. historical upbringing just to think of how this might apply to the Phillipines, Africa, or Australia. Remember, fictional worlds may be nothing at all like Earth.
Period of time before organized groups of specified sapient beings. The specified beings have not developed tools or art of any kind.
Period of time defined by the first appearance of organized groups of the specified sapient beings including the first appearance of tools (manipulation of environment), basic weapons (organized defense), and art (expression of ideas). Tool development during this era begins with stones crafted for specific purposes and ends with copper metallurgy. Art development during this era begins with nothing and ends with pictoral art (e.g. cave drawings). Weapon development for this era begins with clubs and ends with primitive edged weapons including knives and swords. Groups of beings are principally tribal and often nomadic.
Period of time defined by the use of bronze for stronger tools (manipulation of environment) and sophisticated edged weapons (organized defense) and the bow and arrow. Art (expression of ideas) begins to advance to codified writing systems. Permanent communities develop with stone foundations. Mining, forestry, and agriculture have become common in many communities. The wheel is invented and the first wooden-plank hulls appear. The first organized religions and governments are established. Written law begins to appear. It should be noted that no world is wholly within any one era at any one time. World development allows many societies to progress at different rates depending on many factors.
Period of time defined by iron smithing (specifically the development of carbon steel) with advances in manual mass-production including advanced smithing and crafting resulting in the first organized trade guilds. Writing results in rapid growth of religion, government, and education. Naval science began to advance with the invention of the trireme. The end of the iron age is defined by the invention of paper and the introduction of rhetorical algebra.
Period of time from the end of the iron age to the beginning of the medieval or middle age. This age saw little advancement in metalurgy and the sciences, but substantial advancement in government, education, engineering, religion, philosophy, and military tactics. Chariots are in regular use and large ports facilitate trade from remote areas (though oceans cannot be arbitrarily crossed yet). Works of fiction begin to appear as do formal histories. The depiction of art has expanded to both abstract and factual art invoking both color and depth. Coinage becomes a recognizable part of family life, though barter is still the predominant form of exchange.
The medieval age sees the development of large armies and the regular use of explosives. Chemistry advances to include rudimentary pharmacology. Permanent hamlets and villiages give way to towns and cities forcing the development of early sewage, water, and food transport systems. Formal financial systems are developed and coinage is now a regular part of life. Textile and construction technology advance with the development of waterwheel-driven automation. Personal armor gives way to the need for mobility in the face of flintlock firearms. Syncopated algebra is discovered and organized animal husbandry is introduced. Stage theatrics such as the presentation of plays outside of religious contexts are introduced. Ships that can traverse oceans are introduced.
Defined by the rise of colleges and universities and the desire to understand why things work the way they do. Empirical experiment begins to give way to mathematical analysis and modeling. Calculus is discovered and many of the basic sciences are discovered including electricity, biology, thermodynamics, physiology, and material science. By the end of this age ocean-going ships are common place, militaries have converted to firearms and cavalry, governments are introducing representative organization, and individual civil rights are being won. Global trade is introduced.
Defined by the desire or need for growing societies to expand to new lands combined with the technological foundations to permit massive displacement in short periods of time. Cartography and navigation mature. Communication over distances advance with the development of semaphores. Early development of factories to advance mass production is seen and underground sewer and water distribution becomes common. Calculus is discovered and chemistry expands to include regular development of acids, fertilizers, and explosives. Government is in its golden age as law, philosophy, and economics combine to displace religion as the primary motivator for government. The first hot-air balloons are seen.
The industrial age is marked by substantial advancements in science and art as the conceptualization of ideas (modeling) becomes increasingly important. The age sees the development of blimps and dirigibles, as well as the first airplanes. Steam and combustion displaces wind and animals as the primary forms of mobilization. Mass assembly revolutionizes lifestyle as inexpensive manufactured tools, utensils, furniture, and construction supplies produce a boom in city size and living standards. Regular education for the young is introduced, medical sciences become preventative rather than reactive, and global trade matures. Machines are so common that protective trade organizations form to influence government in a way not seen since the introduction of guilds.
This age sees the displacement of religion in favor of science as the principal instructor about environmental, behavioral, physiological, and celestial attributes. The search for truth becomes the search for facts. The scientific method is perfected and with it the development of weapons of mass destruction. The world's first mega-cities are seen and representative government begins to give way to participatory government, allowing for increased protections for previously minority beliefs and biologies. Global communication becomes a reality and machine computation replaces human computation. Advances in chemistry lead to substantial advances in transportation and flight. Theh civilization leaves the planetary atmosphere for the first time and begins to harness nuclear energies.
Here is where we move into the future eras. We likely need to leave the future, near-future and far-future tags alone.