So! Some ideas about these concepts as they apply—in fantasy, not science fiction (though, properly done, fantasy could snitch ideas about these from SF. Why not? SF has snitched plenty from fantasy.)
1) How is it achieved?
In most fantasies, interdimensional/-world/-universal/-what-have-you travel (see point 2) is no small matter. Not just anyone can wake up one morning, say, “I think I’d like my living room on an ocean in another world!”, and so move house. It can be a solemn ritual, or a great effort of magic, or a guarded portal, or an object keyed to a certain person or bloodline, but it’s a matter for the Mighty, not for Joe Schmoe in the street.
I don’t know. Perhaps most people just feel there’s something solemn and awe-inspiring about ripping open the fabric of the space-time continuum.
But is that what you’re doing? Or is it more akin to opening a door from one room in a house to another? Very few people seem to find anything solemn and awe-inspiring about that. They just step through.
Note that I’m not saying you can only have a credible fantasy world if everyone possesses an Amulet of Interplanar Travel; not at all. But think about several things:
- How much effort/resources/materials does it take? Perhaps almost everyone would travel this way if they could, but few people can afford it.
- How easy is it to guard? A single stable portal or a necklace that opens portals, and is the only one of its kind in all the world, would be easier than continual unstable portals that pop up wherever the hell they please, and perhaps mostly in populated areas.
- How widespread is the knowledge? Many times, only a small and secret sect of mages knows that “there are other worlds than these.” On the other hand, almost everyone knows about the existence of magic. So the knowledge of “what” could be widespread, even if most people don’t know “how.”
- What are the motives for keeping this knowledge secret or safe? If the portal affords an economic advantage (see point 3 especially), then of course the small and secret sect of mages might keep it hush-hush to continue enjoying a monopoly on those goods.
Being all woo-woo with mystical portals in the woods that only open on a midsummer full moon night is one way to go, but certainly not the only way.
2) How do people conceive of these other worlds?
Here you’ve got a whole can of worms to fry, because how people think about those other worlds will affect how they think it permissible to treat them.
Perhaps these worlds are seen as simple alternative worlds (or really are; it wouldn’t be the first time an author wrote someone or some group of people in the fantasy world as having true metaphysical knowledge). Analogues of other people exist in them. The history is almost the same except for one little twist. This might encourage people in the “true” world to play around with them, or alternatively—ha-ha—to preserve them because they see their own world as screwed-up and deviating from a divine plan. Or they could treat the alternative worlds as a convenient dumping place for exiles and criminals; just send them into a world where their political faction won, or where they have very strict methods of punishing those who break the law.
Perhaps these worlds are seen as completely separate. This is an especially sensible attitude if inter-world travel is so rare that there’s no possible way to establish a permanent trade route or colony in one of those other places. You might get a family living in several different worlds, but probably not more.
Perhaps they are seen as having purposes that relate to the “real” world. That mysterious “Otherworld” entity in bad pastiches of Celtic fantasy is an example of this. So is the world of dreams, the world of nightmares, and worlds that exist solely as origin places for nasty alien threats like demons. In that case, most people are probably not all that eager to hop into a portal and travel to another place where the very physical rules, as well as metaphysical ones, might be different.
Perhaps the worlds are accessible enough, and exploitable enough, to serve as sources of goods that the “real” world is missing. Then, as long as the exploiters could get back home easily, their attitude would probably resemble that of colonizing empires in our own Earth history. What matters is the mother country, not the colony, and people who care for it as its own place are going to be few and far between. (See point 3. Also, point 4, which I feel goes ignored too often).
Perhaps these worlds are partners or allies; communication is common, and governments in one world or another even send soldiers to help each other. I must admit I haven’t seen many examples of this. Almost always, someone who travels to another world finds the way across cut off from easy access, and is then hailed as the “savior” of that other world. (This is why I automatically distrust most stories of people traveling from Earth to another world, because I know what is going to happen).
Perhaps the other worlds aren’t seen as real at all, and so their inhabitants and resources can be used without remorse—as in Zelazny’s Amber conception.
Decide which you’re going to have, and then be sure to follow the implications of that attitude, or clash of attitudes, faithfully. If you want ruthless merchant families tearing open portals to all and sundry so they can make money, it makes no sense to suddenly reverse the trend and argue that “everyone” in the merchants’ home worlds believes that the other worlds are pure and not to be tampered with.
3) Why the economic relationship?
Yes, those ruthless merchant families, they’ll sell to anyone. So we know from reading a hundred bad fantasies where the authors have read too much bad Renaissance-based fantasy, or seen too many Mafia movies, or got fixated on Amber and never looked further. But sooner or later, you’ve got to ask yourself a basic question: Why would a merchant family look to sell to other worlds, rather than sailing across seas and tunneling underground and gaining a ruthless merchant foothold in countries that already existed? Even Columbus was sailing to countries that he believed existed, not imaginary ones. No one’s going to finance a voyage or exploration that he or she thinks has no chance of succeeding. So what gave him or her the hint or suspicion of another world existing?
Once they have the hint or the suspicion, how did they win control of whatever it is that opens up the portal? If someone else owns the land/grove/set of mystical standing stones/pile of dung the portal opens on, why is he or she going to sell? If it’s an object, how did the merchant family acquire it? If it’s magic, why go to so much trouble setting up this one specific ritual or act of magic? (This is where I come over and stare very hard at authors who just use the old bland excuse, “Oh, the [Interplanar Amulet of Woo-Woo Mystical Travel] had been in her family forever.” How did that happen? If you’re dealing with ruthless merchant families who have made this kind of travel the foundation of a business empire, you should be dealing with hard practicalities. So… *stare*).
What goods do they take through the portal? (Yes, you have to know). Are they ones not available in their own world? Why? Or is the other world also/primarily a market for their own goods? Why? What would happen if the portal collapsed or failed to work, and they couldn’t sell to that world anymore? Would it completely destroy their trade, leaving them with no backup plan? Why?
Who knows this secret? Is it kept in a family, a guild, a circle of families, all the merchants of a particular country or kingdom, the world? Who controls it? The ones who controlled it might not have to trade to the other world at all; they could just tax the hell out of goods coming through the portal, and make people pay for the privilege of accessing it, and sit back, growing fat and rich.
How extensive is the trading operation in the other world? Do the merchants there appear as nomads, as a native business organization (or using a native one for a front), as a family, as a string of tourists? Do they ever get involved in tariff wars, or caught as smugglers? What is the other world’s policy on silk smuggled into another world, anyway?
You could write some damn good economic fantasy with this premise. On the other hand, I can also think of many, many authors who would just use it to get some damned savior into some damned high fantasy world again. So, if you bother setting up an economic premise for contact between worlds at all, know why the hell people wanted to set it up, and how they keep it going.
4) “When you look into the other world, the other world also looks into you.”
It is flat-out fucking amazing to me how many authors treat other worlds as dependent on the existence of a “central” world (usually whichever one the protagonist comes from), even when they claim not to be writing from that setup.
- Example A: Fantasy World Ch’uch’churrgen cannot actually save itself. It must import a savior from Fantasy World Bh’jk’lp, who is so damn Speshul that butterflies fly out of her eyes.
- Example B: Fantasy World Bh’jk’lp is being exploited ruthlessly by Fantasy World Siss’iss’issila’r. They cannot do anything to save themselves because, of course, they are far inferior in magic and/or technology. The Compassionate Hero from Siss’iss’issila’r has to have a crisis of conscience and waltz in to stop said ruthless exploitation, whereupon the natives of Bh’jk’lp fawn on him in a way that is always at least faintly imperialist and creepy, and sometimes outright racism.
- Example C: The action in Fantasy World Siss’iss’issila’r is the “real” action. All other worlds exist as just alternatives or analogues to it, and will stand or fall as it does.
- Example D: Everyone on Fantasy World Ch’uch’churrgen is so damn smart that they’ve been sending exiles and criminals and merchants and people who want to vacation to Fantasy World Bh’jk’lp for years, and no one has ever noticed.
Why doesn’t it ever occur to any fantasy author that, well, those other worlds might have smart people of their own in place, and merchants, and magic, and technology, and spies who will, oh, I don’t know, report things like seeing a giant hole to purple nothingness suddenly gaping in the air?
Start thinking not just about how the protagonist’s world sees other worlds, but how they see the protagonist’s world. They are not necessarily going to be simpler, or blinder, or stupider. They can have their own attitudes about portal travel, and no, those attitudes don’t have to be based on taboos and outdated superstitions and mistaking technology for magic. (Just once I want to see a story where the smug protagonist is wrong about the metaphysical state of the universe, and learns that in fact ripping portals open all the time promptly kills all the kittens in the target world. Just once). And the relationship between worlds can be equal, at least sometimes, and does not have to be reenactment after reenactment of “divide and conquer” or “here comes the savior to save the day!”
Writing about actual equal interaction between worlds would be fascinating. Too bad that almost no one ever does it.
Ooh. And now I have license to write a rant I’ve wanted to write for some time: conlangs. *slobbers, drools*