The ages of Dominion.

[Corinthian]

The differences between EA, MA and LA is one of theme more than of magic.

EA is the Age of Legends, were you seemingly can find a gnome under every rock and giants on every hill. No one is very organized and most people rely on natural ability rather than scholastic ability. Most nations are also very capitol-centric.

MA is the Age of Empires. Magic has been fading a bit but no one is noticing because people are much better organized and can benefit from each others knowledge to a greater extent. Humans replace mythical creatures and nations thus become less about recruitable SC and more about mages and communions.

LA is the Age of the End times. Magic is definitively disappearing and the big empires are all crumbling. And what is worse is that Cthulhu is awakening, Zombie Jesus is returning, the hells are preparing to invade unless sated with blood and many other lesser apocalypses are just around the corner. People turn to death and blood to make up for the lack of other magic. Nations are very decentralized and have few cap only units. Magic potency is decreasing but most nations make up for this by having better diversity.

[TigerBlood]

Magic is more prevelant in earlier ages. Not neccesarily in terms of spells and rituals, but gems tend to be more prevelant as magic sites tend to be more prevelant. Capitals also produce more gems in earlier era's.

Earlier era's tend to have more diverse indies. Not something you can plan for in pretender design/pre game strat, but some independants can definately influence your game.