A Random Generator Is Worth a Thousand Hours of Prep

One of the games I ran this year involved adventurers hopping unexpectedly from plane to plane. While prepping for the game, it quickly became obvious that this was not something that I could prep in the same way I would prep a megadungeon or a scene-based mystery.

So how do we produce interesting planar content without prepping dozens of worlds in exhaustive detail? How do we make sure characters “get” each plane they visit? Especially when they’re not spending much time on each one?

Planes of existence in a fantasy world are exaggerations of the “natural” world (the prime material). They are defined by their defiance of rules or expectations we have about the regular world. To boil it down to a very simplified binary, it helps to think about the two sides of what makes a plane different from the normal world.

Concepts that epitomize the plane. Something inherent and fundamental to the place that defines it. It should usually be immediately obvious and prevalent throughout the plane.

Concepts that are antithetical to the plane. Something that is against the plane’s nature. It should either be prominent for this reason, or conspicuous in its absence.

It’s important to think about both aspects. It’s all well and good to say the elemental plane of fire is epitomized by fire. It’s hot. Fires raging, smoke, lava, and so forth. But that’s not enough. Think about near-absolute absence of water. What does the air feel like as a consequence of that? What is the weather like? Are native creatures violently allergic to water? Or is it a precious treasure to them? Possibly some of both, living side by side?

Let’s put this in motion with some prompt tables. 

What are the local landmarks? What captures the eyes of the visitor?

Epitome

• A castle, city, or other built structure. It’s composed of the essence of the plane, or its structure and function is defined by the presence and abundance of that essence.
• A mountain, body of water, or other superficially “natural” feature. It behaves in a strange or exotic way that reflects the essence of the plane.
• A vortex, portal, or other magical, extraplanar juncture or aperture. Its presence indicates the permeability of the plane, as well as its adjacency to affiliated planes. 
• The site of disaster or change characteristic of the creative or destructive forces of the plane.
• Valuables that are rare on the prime material plane are abundant here (e.g., valuable gems on the elemental plane of earth). 

Antithesis

• The absence of something we take for granted in the normal world (e.g., no fire on a frozen or entropic world).
• A concentration of a rare resource, whether precious or merely exotic (e.g., an oasis on a desert plane).
• A structure, object, or feature that was native to another plane, but was moved to this plane, intentionally or accidentally. Its original nature has been warped or changed by this plane.
• Something removed or exploited and taken elsewhere, leaving tangible absence in its place.
• Something antithetical to this plane, but reshaped by the epitomizing forces here.

What is going on there? How is the situation ripe for adventure?

Epitome 

• The plane’s essence is difficult to understand or interact with, or otherwise defies material plane logic. 
• An event (natural or social) is occurring that restricts or slows visitors’ ability to travel and explore.
• A power from a sympathetic or aligned plane is trying to influence, ally with, or absorb the plane.
• Political, commercial, or social activity focuses on a commodity or treasure that can only be grown, made, or refined in the unique environment of the plane. 
• A gift or creation of the ruler or power on the plane, unique to this place and never taken off-plane, has been damaged, compromised, stolen, or otherwise altered. 

Antithesis

• The antithesis of the plane, something that would be expected in the prime material, is totally absent. Natural laws may be distorted to account for its absence.
• The antithesis of the plane is imprisoned, contained, rationed, or besieged.
• The antithesis of the plane has been memorialized, shunned, sanctioned, or put on display.
• The plane’s enemies or natural opposites are invading.
• Magic is altered in some fundamental way by the absence of something that would normally power, channel, or enable it. 

Who is nearby? Factions? NPCs? Monsters?

Epitome

• Natives of the plane, whose nature is linked to the essence of the plane. They are not merely planar loyalists; their very understanding of the cosmos is defined by the epitome of their plane.
• True believers, either in the ruler of the plane, or the nature of the plane itself. They either transmigrated here after death, or traveled here by magical means.
• The ruler of the plane. Whether a demigod, demon-king, or something stranger.
• Created creatures made of the essence of the plane by archwizards, gods, or others who use the plane’s essence as raw materials.
• Creatures from allied planes who have come to visit, trade, or evangelize. 
• Guardians, persecutors, or judges of the epitome, who seek to destroy, expel, or dominate the antithesis. 

Antithesis

• Creatures trapped here, either intentionally by denizens of the plane, or those stranded by accident.
• Creatures that are valued or respected because – due to their antithetical nature – they can do things or provide value that native denizens cannot. 
• Invaders from an opposed plane who have come here to destroy or conquer part or all of this plane.
• Explorers seeking to secure the epitome of the plane for use as an antithesis on their own plane.

What hazards, traps, or dangers are here?

Epitome

• The essence of the plane is hostile or otherwise dangerous to travelers. Simple actions like movement, breathing, or eating and drinking may be difficult.
• An out-of-control or escalating expression of the epitome is becoming more extreme over time.
• The landscape or physical properties of the plane are changing in a way that defies material plane laws.
• Traps, barriers, or other intentional dangers have been established to keep planar visitors either from accessing sensitive areas, or out of the plane entirely.

Antithesis

• A forced merger or overlap with an opposed plane creates violent or unpredictable interactions.
• Open conflict between factions or individuals over antithetical elements. Multiple factions may seek to recruit outsiders. Innocent bystanders may be caught in the crossfire.
• Remainders of a long-ago planar conflict between epitome and antithesis persist to the present (e.g., metaphysical minefields).
• Weapons deployed in the plane broadly attack a weakness or vulnerability inherent to the epitome of the plane, endangering anyone unfortunate enough to be nearby. 
• Something hazardous was placed here for containment or safekeeping, because the nature of the plane itself or the behavior of its denizens can suppress, control, or monitor the antithetical thing.  
• Something stolen from an antithetical plane, which is disruptive or wrong in this place.

Here is our random generator that incorporates all these bits into just four prompts. We can adjust it some more going forward; maybe we want the epitomes to be several times more likely than the antithesis.

https://perchance.org/whatishappeningonthisplane

Bonus Table: How Did You Get Into This Mess? (d12)

1. A wizard did it. A spell was cast upon you. It went wrong.
2. A wizard did it (the wizard was you). You tried to cast a spell. It went wrong.
3. Portal passenger. You wandered into a portal and now you’re here, wherever here is.
4. For science. An experiment went awry. Whether you were an experimenter or a test subject doesn’t matter now.
5. Trapped! A nefarious entity created an inter-planar trap. Congratulations, you have sprung that trap.
6. Hot pursuit. Something is chasing you across the planes. You don’t know what it is, but it seems to be accelerating and salivating.
7. Left behind. You were hired for some specific job or expertise, but the person who hired you left you behind. 
8. Cursed! Whether it happened to a distant ancestor long ago, or to you personally last week, the terrible curse has sent you hurtling between worlds.
9. Debt. You owe such a vast amount that when a particularly dodgy character offered you an especially suspicious way to get out of town -- really, really far out of town -- you took it.
10. Transmigration. You died. While your soul was on its way to the afterlife, it took a wrong turn, and you are now lost. Depending on where you were destined to go in the afterlife, this may be either relatively good or relatively bad news for you.
11. Prison break. You were trapped in Tartarus, a demiplane, or some similar extraplanar confinement. You're free now but you didn't plan too far beyond your escape.
12. Sole survivor. You were part of a highly larger team that was intentionally traveling the planes. You're not in a good situation now, but you wouldn't trade places with your recently deceased companions.