A fourth age

[HoneyBadger]

Space battles, Dom3 style, would be a hell of a lot of fun.
For instance, instead of water nations and land nations, you've got, say, normal space and hyperspace, with some nations able to cross between the two. Each province would be a planet, and gems would be substituted for rare resources, like anti-iron. Units become ships, space monsters are easy, sites would need some extensive reworking, but the maps themselves I would think would be a lot of fun to design (round "provinces", instead of mountains, asteroid fields, forests become organic infestations or Gaia-type planets, whatever). Forged items...I dunno how they'd be handled, but instead of regular helmets, armour, etc. you'd have various weapon and defense systems, special abilities, whatever. Spells become futuristic special technologies, summoned units become special projects. Stealth is pretty self-explanatory, but seduction becomes computer override.

It would ofcourse be a huge amount of work for one person to design, but the possibilities are wide open, and a space scenario, done well, could probably outdo MOO2.