Has anyone else done this? I'm interested in any ideas that anyone has or might have used in their own campaign.
I already ran a short time-travel adventure for my Greyhawk Campaign where they ended up the year 2000 for a game session. Everyone seemed to have a lot of fun.
I always thought that enough technological marvels were already "intruding" upon GH not to feel the need to make players visit more advanced civilizations.
In-between the legacy of Leuk-O & Lum, Murlynd's "gadgets", the futuristic items from Expedition to the Barrier Peaks, and the so-called "city of the gods" in Blackmoor, there was enough to drive anyone mad.
Back when I ran EttBP (in the 1e days), I used Gamma World to make things more interesting and allowed the players to use a teleporter (à la Star Trek) to gain access to the legendary and infamous starship Warden (if anyone here is old enough to remember Metamorphosis Alpha..) which, IMC, orbited Oerth (it was one of its sections which had crashed down in the Barrier Peaks).
My (then) players didn't much care for it and I ended that ill-fated adventure before it turned into a TPK (personally, I had fun but that's not the goal of the game).
The only other attempt I made was to run the City Beyond the Gate special adventure (Dragon mag. #100). That one was rather successful once I made it clear to the players I would allow them a chance to return to their own world.
The greatest kingdoms of the Flanaess would be either fables or obscure footnotes in history. Does your average person on the street realize that before there was a Germany, there was a Holy Roman Empire, and before that dozens of tiny kingdoms ruled by robber barons and warlords, and before that the Old Roman Empire, and before that a bunch of barbarian tribes? There might possibly be a United Kingdom of the Flanaess by 2000 CY. Would it be a monarchy, or would the peoples of the Flanaess adopt democracy as our own world has (for the so-called civilized part of it, anyway)?
Would the Flanaess even look the same geographically? What if the Land of Black Ice really is expanding? Would everything north of the Sheldomar valley be covered in black ice? Also, there seems to be alot more volcanic activity on Oerik than on Earth, and possibly more shifting of land masses. It might look at least somewhat different in 2000 CY.
The demihumans might have all died out or sailed east across the Solnor to some legendary fairyland, but if not, their natural tendencies would be expressed in completely new ways. Gnomes and dwarves might still be the best engineers, building cities that look like Coruscant from the Star Wars movies. Elves might reject such urbanization, leading to elven "green parties" that lobby for conservation of the world's last natural wonders (such as Gnarley National Park).
What about the deities and demigods? Would their services not be televized? Wouldn't the clergy of St. Cuthbert ask you to send donations to help fund Cuthbertian theme parks? What would Iuz be doing if he were still around? Probably developing weapons of mass destruction.
Considering that magic drives civilization on Oerth, rather than science, maybe things wouldn't look so different after all. Why develop film when illusions are so much more vivid? Who needs to harness electricity in a world full of everburning torches? Why bother developing medicine when clerics and druids can cure whatever ails you? Gunpowder is unreliable on Oerth, so projectile weapons are probably the deadliest weapons in war, second to offensive magic, of course. So longbows and crossbows are still in wide use, as are melee weapons, and therefore personal armor. Maybe lasers work okay on Oerth, leading to laser guns instead. Maybe Oerth in 2000 CY would resemble [gasp!] Eberron! ;)
I've always considered the Flanaess to have ca. 1800 technology (minus the printing press, gunpowder and related technology), but the Suel Imperium in 5094 SD (which the players visited for a month) was more like ca. 1900; they recovered a printing press from the Sea of Dust when they returned to the present, and there is now at least one regular newspaper (the Greyhawk Gazette, which includes reporters, artists, paperboys and so on) and attendant businesses, such as a papermill. Even the Lord Mayor, Nerof Gasgal, has a regular column (through which he dispenses his propaganda)...
Technology isn't where it's at, however: it's very rare and little understood, and magic is still #1, but with a newspaper, the new items developed in Dark Gate for exploration of the Sea of Dust (sunglasses etc), modern Greyhawk (without going 1,400 years into the future) is starting to look a little like 21st Century Earth in some respects.
I think it might be easier to run a Modern campaign with magic and gods added into it than a D&D campaign with technology, but I've never tried something like it.
The main differences would be much of the super tech of Eberron would be replaced by actual steam and gear technology instead of magic technology. Of course that's if you buy into the idea that magic is fading from Greyhawk.
I think I would have the tech top out at muskets and canons versus lasers and phasers just from D&D versus d20 Modern perspective. Otherwise why not just run an Urban Arcana game set in the Greyhawk of the future?
That said, I am intrigued by the mix of 17th/18th century technical enlightenment (pre-industrial, but post-Renaissance) with fading magic that would likely characterise the world of Pluffet Smedger the Elder around 998 CY. I'm assuming that the Fading of Magic also removes the barrier to gunpowder, so you can being to see countries like Nyrond and Aerdy (reunited now for several centuries) having at each other with large field armies armed with musket, pike and canon as well as spell, sword and fireball.
Essentially, mages, sorcerors and those manifesting divine magic would be extremely rare and possibly persecuted by a monotheistic new faith - perhaps modified Pholtine cult that arises with the complete withdrawal of the gods from the Oerth (the only way to deny Iuz his ultimate victory). The Fading also means the fading of demi-human and monsters leaving humans to inherit the Oerth.
I know some people (CSL especially) hate this idea, but it kind of completes the picture of GH for me - opening v. low to zero magic settings in GH to counterpoint the comparatively high magic of the Age of the Two Empires. That way everyone can in theory pitch their preferred level of magic to a timeframe in the Flanaess.
And besides, it's Canon, so there! ;)