Other Planes of Existence
Other Planes of Existence
A campaign can extend across several game worlds instead of being tied to just one. This makes it possible to explore themes that do not work well in a single-world campaign. For instance, the PCs might visit several radically different settings in the course of a single adventure, and the world – at least one world – could actually end without the campaign coming to an abrupt halt.
Multi-world campaigns greatly increase the players' options. They get to experience several settings and genres while playing the same characters. And if they grow tired of the current world, the GM can simply move the action to a new one. This can give a flagging campaign a new lease on life.
However, a multi-world campaign increases the GM's workload. Instead of having to design one world in detail, he has to create many. He must also address the question of travel between worlds, which can be as much work as designing a world!
The GM needs to be prepared to deal with another potential problem. Many players see little point in working hard to achieve goals in one world if they believe the fruits of their labors will be lost when the campaign moves to the next. This can lead to a game-disrupting sense of detachment. To prevent this, the GM must strengthen campaign continuity by creating storylines that span worlds...which adds even more work.
Any GM should know the limits of his time and ability, and consult with his players ahead of time. This is even truer for GMs who wish to run crossworld campaigns.
Travel Between Game Worlds
One of the chief purposes of the GURPS design is to let players explore multiple game worlds without learning a whole new set of rules each time. A player can participate in several different campaigns, each in a different place or time, and play a different character in each campaign. Each character stays in his own world. But the characters can also move from one game world to another. This can happen in three ways:
- A player can develop a character in one game world and then bring that character into another game world. An example might be a medieval wizard, hurled hundreds of years into the future by a magic spell, participating in a WWII adventure.
- An entire campaign can move from one game world to another. For example, suppose the party is the crew of an interstellar trading ship. They crash-land on a primitive planet. Until they can make their way to the spaceport, on the other side of the world, they are effectively living in the 12th century!
- The campaign can include multiple game worlds by design, along with the means to travel between them.
Differences in Worlds
As a rule, the more different two worlds are, the harder it should be for PCs to move between them deliberately. Significant differences would include:
- Magical world vs. technological world.
- Very low-tech world vs. very high-tech world.
- Largely human or all-human world vs. world with many races.
- War-wracked, plague-ridden world vs. peaceful, decadent world.
- Fantasy world vs. strictly historical, "real" world.
Certainly, any or all of these differences could exist on a single planet! But they would not be found next door to each other.
Likewise, the GM should make travel between incompatible worlds difficult. This achieves an effect that is very rare in gaming; it improves both realism and playability. Players will appreciate the fact that "rule changes" come only with warning.
Possible obstacles to interworld travel include all the standard geographical barriers: high mountain ranges, wide oceans, extensive deserts or badlands, swampy jungles, etc. Magical barriers are also a possibility, as are intervening hostile lands. GMs may also have their different worlds located literally on different worlds. The problems of interplanetary travel at low TLs are not to be taken lightly, but powerful magic can do almost anything. Of course, such powerful magic is not likely to be within the PCs' control...
Alternate Earths
"Alternate Earths" are worlds that are like Earth...but different in some way. The differences might be tiny (Kennedy's picture is on the dime), huge (Kennedy is now King of the Western Hemisphere), or unbelievable (the Earth is ruled by intelligent lizards who have the same cultures, languages, and politics as us).
A "reasonable" alternate history is sometimes called a parallel world. Inventing parallel worlds is a great intellectual game. One way to approach it is to pick a historical event and ask, "What if this were different?" What if Lincoln had survived Booth's attack? What if Chamberlain had stood up to Hitler? What if Eric the Red had died in a brawl at age 16?
As the GM, you can invent any sort of alternate Earth. You can assume as many basic points of difference as you like. But it is interesting to see what logical consequences you can develop from one change. Pick any historical event – great or small – and ask yourself, "What if this had gone differently?"
For an entire campaign setting built around alternate Earths, with many examples, see Infinite Worlds.
Virtual Realities
A virtual reality (or "virtuality") is basically a synthetic plane of existence generated by high technology. Much of the advice given here for cross-world campaigns is equally valid in high-tech campaigns that feature an immersive "cyberspace" where the PCs can have adventures and interact with the real world indirectly.
Types of Realities
Many different types of game worlds can exist in a cross-world campaign. These are often called "planes of existence" (or "planes"), "dimensions," "realities," "realms," or "universes" to distinguish them from distant lands or planets in the same physical universe, which are sometimes called "game worlds" as well.
Physical Realities
These are planes of existence that travelers can actually visit – either in body or in spirit – much as they would visit another country or planet. The defining feature of such realms is that visitors possess a physical body during their stay. This might be their normal body...or it might be a "spirit body" that is corporeal only within that realm.
The most common physical reality is the alternate world (also known as an "alternate history" or "alternate timeline"). This is almost the same as the PCs’ home world, but in this world, history diverged at some pivotal event, creating a different reality. (See Alternate Earths.)
Almost as common is the mirror world. Mirror worlds look just like the PCs' home world, but the resemblance is cosmetic. No reasonable sequence of historical shifts could explain the differences! A good example is the world of faerie: it looks a lot like our world, but it is actually a magical realm ruled by powerful spirits. Another common example is the "evil parallel." Many things about the world are similar, but personalities and even governments are "opposite": republics become dictatorships, saints become fiends, and so on.
Some physical realities might be even more alien. At best, they might be as different as alien planets within our universe. At worst, the laws of physics might be different, or suspended. Humans might be unable to survive there!
Interpenetrating Planes
Two or more planes of existence might interpenetrate, with each location in one world corresponding to a similar location in all the others. Such realms are generally distinct from one another, and invisible to each other's inhabitants – although some gifted people, such as mediums and seers, might be able to perceive more than one reality at a time. Perhaps even ordinary people can occasionally see the inhabitants of the other realms, but regard them as ghosts.
This is a common way to look at "dream," "phantom," and "spirit" realms in fiction. Often, travelers to such planes do not go anywhere; they just shift their perceptions.
Phases
A phase is not a destination in itself, but an invisible sub-dimension of one specific reality. Unlike an interpenetrating plane, it is not distinct from its partner reality; it merely represents a physical or supernatural "wavelength" different from the standard one. The main use of such realms in fiction is to let travelers rapidly bridge the gap between two locations within the same physical reality.
An example of a phase is the ethereal state that those with Insubstantiality assume in order to walk through physical obstacles. Another example, common in science fiction, is hyperspace: the "space" into which stardrives shift starships for faster-than-light travel.
Voids
A void surrounds physical realities in much the same way that outer space surrounds stars and planets. A void differs from an interpenetrating plane in that it touches realities without overlapping them. It differs from a phase in that it is not a sub-dimension of just one reality, but a "super-dimension" that engulfs and connects all realities.
Like the ocean and outer space, the void in fiction is a dramatic device that serves one purpose above all others: it mediates travel – in this case, interplanar travel. For instance, popular interpretations of the "astral" plane suggest that it is a void that travelers must pass through when using magic or psionics to journey between realities.
Planar Cosmology
The GM must determine what planes of existence are present – in number and in type – and how they interact. The possibilities are endless! Here are some popular arrangements.
Worlds Within Worlds
In this model, realities are nested one within the next – like the layers of an onion. Alternate worlds or interpenetrating planes might exist on a more-or-less equal footing at some levels of this hierarchy, but the truly important events in the campaign always involve movement up or down the hierarchy, not across any one level.
This structure lets the GM hide secrets within secrets, and offers a classic explanation for many supernatural powers and beings: "They come from a higher plane." As a result, it is well suited to multiple-reality campaigns with a strong supernatural flavor.
- Example: A fantasy campaign takes place in a fairly ordinary physical reality – a world with mountains, oceans, stars in the sky, etc. "Inside" this world, there is a phase called the Ethereal Plane; this explains magical effects such as teleportation and walking through walls. Surrounding the physical world is an inner void: the Spirit World, realm of ghosts. The Spirit World does not overlap the physical world; instead, it is a layer that dead souls (and powerful wizards!) must traverse on their way to an outer void known as the Astral Plane. The Astral Plane, in turn, allows travel to the alien "physical" realities of demons, gods, and other higher powers.
Parallel Worlds
This cosmology features multiple physical realities standing shoulder to shoulder. Most are true alternate realities, but a few might be mirror worlds. Some might even be "pressed so close together" that they interpenetrate. The defining feature is that there are no planes of existence within, between, or surrounding these worlds. All realities are on an equal footing, and travel involves a direct shift as opposed to a journey through some kind of intervening dimension.
This structure eliminates mystical journeys, speeds the act of travel, and provides a rational explanation for weird events ("ghosts" are just inhabitants of unusually close realities, "demons" are merely ugly interplanar voyagers, etc.). These features make it desirable for science-fiction campaigns centered on cross-world travel and trade.
This framework is conceptually simple, but the GM can make it as convoluted as he wishes. Travelers might only be able to visit "adjacent" worlds...and a satisfactory definition of "adjacent" could defy scientists' best efforts. It might take multiple hops to travel to some worlds, and while worlds might form a ring or other simple pattern, the GM could instead decree that they exhibit a brain-busting geometry that humans and their best computers simply cannot map. Use your imagination.
Mixing It Up
The GM is free to add any number of twists. For instance:
- Start with a hierarchy of realities, as explained under Worlds Within Worlds, but place parallel worlds on some tiers of the hierarchy.
- Start with worlds that abut on worlds, as described for Parallel Worlds, but make certain "worlds" fully realized hierarchies of dimensions instead of simple physical realities.
- Add any number of distinct phases to some or all of the worlds in the setting (e.g., each physical reality might have its own hyperspace and an ethereal plane).
Interplanar Travel
Many stories that feature multiple worlds assume that travel between those worlds is a one-way trip: unlucky (or lucky!) travelers somehow fall through the gap between worlds. But regular travel between worlds is an interesting possibility, as it lets explorers study, exploit, and perhaps even conquer entire worlds. In this case, the most important question to answer is, "How do the adventurers get there?"
Instantaneous vs. Time-Consuming Travel
Travel between worlds could be a "Poof! You’re there!" phenomenon: the heroes just have to cast a spell, push a button, walk under a hill, etc. Or it might be a slow process, comparable to sea or space travel. Both approaches have pros and cons.
Instantaneous travel – like the Jumper advantage and Plane Shift spell – allows furious, universe-spanning action, with the heroes and their foes battling from one reality to the next. However, some players will try to avoid enemies (and Debt, Duties, etc.) this way, sapping drama instead of adding to it. This kind of travel also encourages brisk interplanar trade, which is great fun...until it destroys the campaign's economy. In general, if interplanar travel is to be quick, the GM should make the means of travel hard to come by, introduce reasonable risks (e.g., nasty surprises on failed Plane Shift rolls), limit what travelers can carry, and make it clear that some alternate worlds are dangerous.
If interplanar travel takes time, the GM must determine how much time passes, and at what rate relative to time in the PCs' home world. The primary advantage of time-consuming travel is that the trip itself is an adventure. The downside is that the campaign can get bogged down in travel. Many players grow bored if their characters must make long trips to achieve their goals. If the GM chooses this option, he should be prepared to build an adventure around each trip, or let the PCs spend their time on gainful long-term projects such as study, invention, and magical enchantment.
Physical Travel vs. Projection
Interplanar travelers sometimes visit other planes of existence in person, but this is not the only option. Visitors might instead journey to other realities in mind or in spirit. Physical travel (teleporting between worlds, moving there in some kind of vehicle, etc.) lets the GM use classic "hooks" like money and physical danger to steer the campaign. It is also involves less bookkeeping: the PCs have the same abilities and equipment as in their home world. However, physical travel lets the PCs vanish bodily, perhaps along with their possessions, making it possible to escape the consequences of their actions. It also opens the door to commodities trading, which can have unwelcome economic effects. The GM should take care to create adversaries who can follow the PCs wherever they go, and should consider imposing strict limits on the physical goods that can accompany travelers (e.g., "You arrive naked.").
Projection involves traveling to other planes as a mind or spirit while the body remains behind. This solves many of the problems GMs have with cross-world campaigns. What belongs in each world stays in that world. The only thing that moves between worlds is information – and the GM can easily control that. There are two disadvantages. First, the GM must keep records for both the PCs' physical selves and their projections. (The GM could just say that the projection is the same as the original, but he would be discarding an interesting dramatic tool.) Second, players might feel that other realms aren't "real," and behave accordingly. The solution here is to let them...and then have the consequences of their actions show up in their "real" world!
Modes of Travel
Finally, the GM must decide on the actual mechanism used for interpla- nar travel. Options include:
Artifacts:
Interplanar travel relies on magical, psionic, superscience, or weird science gadgetry. There are endless possibilities, from hyperdrives and parachronic conveyors to magic mirrors and stone circles. Be sure to specify whether the artifact goes with the traveler to the other side, or merely sends him there – and whether it's good for the return trip!
Right Time, Right Place:
Anyone can reach other planes, but only under certain conditions: while dreaming, on certain days of the year ("When the stars are right!"), at specific places (such as the "hollow hills" of faerie myth, or a wormhole in deep space), and so on – and possibly more than one of the above.
Special Powers:
Travelers need advantages (e.g., Jumper), magic spells (e.g., Plane Shift), or similar powers to move between worlds. To keep PCs with such abilities from going off and leaving the rest behind, the GM should either require all PCs to have such abilities or make sure that the person in charge of transportation has the power to convey his companions (and that the player is responsible enough to do so).