afroakuma's Planar Questions Thread! (You ask, I'll answer)

[afroakuma]

Hello the boards!

I'm bored and have several hours to kill. If you have any questions related to life on the Planes (whether 2E Planescape, 3.5 or my own personal canon) I'm open for business until further notice and will be watching this thread for a while. Bring it on!

[Snowbluff]

If I am in a weightless plane, do I need to hold the black holes I am storing there together with glue?

[afroakuma]

Nope. Gravity can exist within a weightless plane, it is simply not inherent to the matter of the plane itself. Even if that were not the case, the result of the forces that created the black hole in the first place would remain a mass sufficiently dense and compacted as to hold itself together in the absence of an external, separating force.

[AuraTwilight]

Describe the Ordial Plane.

[Morcleon]

1. What does the edge of a demiplane/non-infinite plane look like?

2. What would happen if you put the tarrasque on the Positive Energy Plane? Would it die by healing? Would it be caught in an endless loop of exploding every so often, only to be reformed six seconds later?

3. What does a plane look like from the outside? What happens when you smash two of them together?

4. Does the shadowcraft mage's shadow illusion class feature get boosted by 10% on the Plane of Shadow?

5. Subjective gravity states "each individual". What happens when you get two minds in one body (via schism or possession or similar), and they want to go different directions?

6. Do time traits affect time stop and similar?

7. Undead and constructs are immune to Fortitude save-effects unless they work on objects too. A strongly positive-dominant plane offers a Fort save to avoid exploding, but specifies creatures. Can these two creature types get infinite HP on the Positive Energy Plane?

8. How much water pressure is there on the Elemental Plane of Water?

9. How much air pressure is there on the Elemental Plane of Air?

10. How much earth pressure is there on the Elemental Plane of Earth?

11. How much fire pressure is there on the Elemental Plane of Fire?

[afroakuma]

The Ordial Plane is a mysterious place. The Rule of Three and the Unity of Rings both seem to confirm its existence as the Plane of Proof - that which links matter and belief, supplying form to the Outer Planes - yet it has never been conclusively confirmed by planar explorers.

Some believe it may be that outer realm in which Vestiges are trapped, though this is unlikely. Many have conjectured that it might be inhabited by those creatures which call both the Ethereal and the Astral home - completing the trine, if you will. Those creatures certainly aren't telling.

The Ordial Plane, if it does exist, would likely mirror characteristics of the Ethereal and Astral Planes; no layers, just an infinite expanse, and with borders to the Inner and Outer Planes. As the conventional plane (in the sense of being a part of this multiverse) furthest from the Material Plane, it is inherently difficult for Primes to conceive of. This may be why planar travelers have never found it - stumbling across a gate to the Ordial, they may not have been able to recognize the portal for what it was, or even the realm beyond for a different place.

[afroakuma]

1. What does the edge of a demiplane/non-infinite plane look like?

From the outside, a demiplane has no "edge" - it's a bubble of some sort, usually spherical, floating in the Deep Ethereal.

From within, the specific nature of the demiplane determines that. It may be that the "edge" is a shoreline, or an infinite wall. It could be above the clouds in the skies surrounding a planetoid. It could be a door at the base of a stairwell, or checkerboard tiles breaking apart and spiraling slowly into a starry endless void. What the space "beyond" a demiplane looks like is as much a quality inherent to that demiplane as anything else.

2. What would happen if you put the tarrasque on the Positive Energy Plane? Would it die by healing? Would it be caught in an endless loop of exploding every so often, only to be reformed six seconds later?

Per the rules of 3.5, the Positive Energy Plane can't explode the tarrasque (as its regeneration allows it to ignore instant death attacks from any form of "attack" that could not normally deal it lethal damage - and nothing deals lethal damage to the tarrasque, especially not being really really healthy). I may be misreading this, but that's what the d20srd seems to be providing me with.

3. What does a plane look like from the outside? What happens when you smash two of them together?

A demiplane usually looks like a sphere from the outside, with specific visual characteristics based on the nature of that plane. Infinite planes have no "outside" that can be seen from any practical position.

Planes that collide tend to "emulsify" briefly - that is, there's a crossover in the collision zone, with elements from each appearing. Actual collision doesn't happen, but some planes naturally brush against one another - the Inner Planes all brush against a few, and there are places in the Outer Planes that show a bit of bordering as well.

4. Does the shadowcraft mage's shadow illusion class feature get boosted by 10% on the Plane of Shadow?

Don't have my books with me right now; can't look that up.

5. Subjective gravity states "each individual". What happens when you get two minds in one body (via schism or possession or similar), and they want to go different directions?

The stronger of the two minds prevails. When both minds are equally strong... have you ever heard the one about dropping a cat with a slice of peanut-buttered bread on its back?

6. Do time traits affect time stop and similar?

If the book doesn't say so, then no they do not. Planes with time traits should naturally interact with time magics in some fashion regardless.

7. Undead and constructs are immune to Fortitude save-effects unless they work on objects too. A strongly positive-dominant plane offers a Fort save to avoid exploding, but specifies creatures. Can these two creature types get infinite HP on the Positive Energy Plane?

Positive energy on the Positive Energy Plane should affect objects as well, with the same dramatic results (glowing and exploding). This appears to be a rules oversight, and an unfortunate one. Positive energy should affect undead in the same way that negative energy affects the living, but of course, these books were written from the perspective of having a standard adventuring party, and don't do well at addressing issues of monstrous entities brought there. This is why, for example, ravids have no immunity to their home plane's effects and deal damage with their positive energy lash. I would recommend that DMs treat the Positive Energy Plane as hazardous to both undead and constructs, and not at all hazardous to ravids.

8. How much water pressure is there on the Elemental Plane of Water?

None of any note. You're perfectly safe to be there, provided you can breathe. And swim.

9. How much air pressure is there on the Elemental Plane of Air?

Once again, none of any note. You're quite safe on the Plane of Air - it's easily the most gentle of the four.

10. How much earth pressure is there on the Elemental Plane of Earth?

Ohhhhh a lot. Cause a cave-in (entirely possible!) and you'll feel a substantial amount of earth pressure.

[Eurus]

What happens if you try to take a Petitioner off its home plane?

I've always heard it said that there are infinite demons, but that devils reproduce through soul-larvae. If there are infinite demons, why haven't they won the blood war? Even if a vanishingly tiny percentage of demonkind cares enough to participate at any given time, that's still a literally infinite army. Tactics only makes up for so much. Conversely, if there are a finite number of devils, but each layer of Baator is supposed to be infinitely large, what happens to all the empty space?

[afroakuma]

What happens if you try to take a Petitioner off its home plane?

Petitioners can leave their home planes, but they're in tremendous danger if they do so. A petitioner slain on its home plane merges with the plane and can potentially be reformed with powerful intervention. A petitioner slain elsewhere has its energies dispersed and cannot be reformed.

I've always heard it said that there are infinite demons, but that devils reproduce through soul-larvae. If there are infinite demons, why haven't they won the blood war? Even if a vanishingly tiny percentage of demonkind cares enough to participate at any given time, that's still a literally infinite army. Tactics only makes up for so much.

Demons are infinite. Devils are transfinite. Much of the rabble of demonkind forced to serve in the War is weak, useless and/or treacherous. This isn't a case of there being infinite balors versus countable pit fiends - there are EXCEEDINGLY few balors involved in the Blood War at any time, those mariliths involved are almost all wasting their time, and the nalfeshnees and glabrezu have other preoccupations that largely keep them removed from the war. In short, there's only a very small amount of contribution by true tanar'ri to the Blood War, and much of that involves the coercion of the molydei. None of the major Demon Princes care about the Blood War.

On the devil side, there's much more organization and force commitment. Bel is mandated by the Lord Below to prosecute the War on the side of Law, and has the Dark Eight working to ensure the supremacy of Baator in the conflict. Every rank from lemures up through to pit fiends can be engaged in the War. It's not only a matter of tactics (mariliths are excellent tacticians, and when a molydeus can be bothered to directly captain a war effort, there will be many dead baatezu indeed), it's a matter of sheer commitment and power level. Demons win on numbers, but devils win on force.

Don't discount the role the yugoloths play in keeping the balance, either. The Blood War won't end until someone very high-up wants it to.

(Demons also reproduce through larvae - larvae are the key to the whole of the War, used to create helpers such as imps and quasits or melted into lemures and dretches to fuel the raw numbers on each side.

The key difference is that manes can form from the Abyss as raw petitioner souls, whereas the baatezu are not natives of their plane and must hunt down nupperibos to render into lemures.)

Conversely, if there are a finite number of devils, but each layer of Baator is supposed to be infinitely large, what happens to all the empty space?

Devils are transfinite - their numbers, while not infinite, are certainly uncountable. There's not a tremendous amount of empty real estate as a result. Devils, unlike demons, also care about the empty space more. You're more likely to find an empty cavern in the Abyss than in Hell.

[Larkas]

Now these are things that I never quite wrapped my head around:

1) Both Planescape (IIRC) and 3.5 describe the Elemental Planes as both infinite and bordering other Elemental (or Para-Elemental, or Quasi-Elemental, or Energy) Planes. Hence, where the Water Elemental Plane borders the Air Elemental Planes, you'd have steam. But how can something be both infinite AND border something else?

2) The same applies for the Outer Planes in some measure. There are gates, so it's not exactly a border. But there are also River Styx and Oceanus, the Yggdrasil and other things that link stuff. How can you picture, for example, Oceanus passing through Arcadia and Ysgard? Do the shores form a continuum (and, thus, there is a real border, like in the Inner Planes), or does only a tiny fraction of the river exist in both planes (imagine: patch of land-river-patch of land)? Both are somewhat strange propositions!

3) In Planescape, I remember some locations changing planes because of a shift in alignment. A place in Mechanus that became too Good-aligned could suddenly become part of Elysium. Now, how do that work? Is there a land transfer, or are only buildings and/or features transfered?

[afroakuma]

Now these are things that I never quite wrapped my head around:

1) Both Planescape (IIRC) and 3.5 describe the Elemental Planes as both infinite and bordering other Elemental (or Para-Elemental, or Quasi-Elemental, or Energy) Planes. Hence, where the Water Elemental Plane borders the Air Elemental Planes, you'd have steam. But how can something be both infinite AND border something else?

Well, I'll explain by analogy.

Start at 0, and count upward by ones. The set of numbers you count (if you could count forever) would be "infinite;" that is to say, it is uncountable and unending. Nonetheless, no matter how high you count, I always have one "end" - the zero cannot move. Now start at zero and count downward by ones. Again, you have an "infinite" set of numbers - you will never reach a number so low that it cannot be bested by subtracting one - yet it has a defined limit.

Compare both of these to the entire set of integers - it is also infinite, and yet logically must be larger than either set individually, comprising as it does both of the previous infinities. Now take the real numbers - infinitely more infinite than the integers.

The way of the planes is such that there's no physical (0,0) at which all four elemental planes would originate and move away from, nor is there a point (X, 0) or (0, Y) that is "fixed" in planar space where the border is located. Rather, these realms are infinite, and within these realms exists a border with another, which can be traveled to but is not a defined PHYSICAL limit.

2) The same applies for the Outer Planes in some measure. There are gates, so it's not exactly a border. But there are also River Styx and Oceanus, the Yggdrasil and other things that link stuff. How can you picture, for example, Oceanus passing through Arcadia and Ysgard? Do the shores form a continuum (and, thus, there is a real border, like in the Inner Planes), or does only a tiny fraction of the river exist in both planes (imagine: patch of land-river-patch of land)? Both are somewhat strange propositions!

Again a metaphysical quirk - the shores do not (typically) form a continuum, nor do the rivers, the tree and the mountain have defined points at which there is a changeover. The analogy for this would be to go into Paint and draw a series of lines one next to another that shift from (255,0,0) to (255,255,0). Looking at such a band of color, you could tell me that you started at red and went to yellow, and you could probably point out orange to me, but is where you think orange begins the same place that I think orange begins? Do you think you would pick the same place at a glance, every time? And when you have determined where orange begins, will you be able to say, conclusively, looking one pixel to the left, that the line to the left is definitively "red" and not "orange?"

3) In Planescape, I remember some locations changing planes because of a shift in alignment. A place in Mechanus that became too Good-aligned could suddenly become part of Elysium. Now, how do that work? Is there a land transfer, or are only buildings and/or features transfered?

There can be a land transfer from time to time, too, though the land would gradually take on traits in accordance with its new environment. A transition from Mechanus to Elysium is almost certainly out of the question, however - goodness appearing in pure law would move a location into Arcadia first, then Celestia, then Bytopia. It's not the most sudden of transitions. There won't be a crater left over or a town crushed under SURPRISE TOURISM ROCK, though.

[Grinner]

Why are there so many themed planes (Air, Fire, Water, Earth, Negative, Astral, over a dozen different Alignment Planes, etc.) but only one Material Plane?

Edit: @afroakuma: I hope you catch this.

To clarify, that's a lot of support structure for one lousy plane. What's so important about it?

[afroakuma]

Why are there so many themed planes (Air, Fire, Water, Earth, Negative, Astral, over a dozen different Alignment Planes, etc.) but only one Material Plane?

The Inner Planes are the "building blocks" of matter itself. The Outer Planes are the embodiments and reinforcements of cosmic forces and belief. The Prime Material Plane is the fulcrum of it all, with the Transitive Planes being mediums for matter to join together and belief to provide meaning and purpose. In other words, the Prime is the "sum" of the rest of the cosmology.

That said, there are other Material Planes. They can be traveled to by entering the Deep Ethereal, or trekking into the secret routes in the Plane of Shadow. Eberron is commonly held to be a different Material Plane from that which houses Toril, Krynn and Oerth, for example. The distinction between other spheres (same Prime, different "solar system") and other Primes isn't well-explored and a great many worlds are considered to share the same Material Plane, but others do exist and have been seen.

The Inner Planes are also the original planes. The Prime is the conflux of those forces joining (the 0,0 on the coordinate axis, if you will) and provides the belief that underpins the Outer Planes. Depending on where your interests lie, it's either an uninteresting parasite (Inner), your world (Prime) or your life source and battleground (Outer).

[Grinner]

@afroakuma: That makes sense. Thanks.

[Larkas]

Well, I'll explain by analogy.

Start at 0, and count upward by ones. The set of numbers you count (if you could count forever) would be "infinite;" that is to say, it is uncountable and unending. Nonetheless, no matter how high you count, I always have one "end" - the zero cannot move. Now start at zero and count downward by ones. Again, you have an "infinite" set of numbers - you will never reach a number so low that it cannot be bested by subtracting one - yet it has a defined limit.

Compare both of these to the entire set of integers - it is also infinite, and yet logically must be larger than either set individually, comprising as it does both of the previous infinities. Now take the real numbers - infinitely more infinite than the integers.

The way of the planes is such that there's no physical (0,0) at which all four elemental planes would originate and move away from, nor is there a point (X, 0) or (0, Y) that is "fixed" in planar space where the border is located. Rather, these realms are infinite, and within these realms exists a border with another, which can be traveled to but is not a defined PHYSICAL limit.

Hmmmm, I think I get it. But wouldn't it make sense for a "larger infinite" to be there encompassing everything? I'm trying to avoid thinking 4E's Elemental Chaos, but I can't think of a better visualization.

Again a metaphysical quirk - the shores do not (typically) form a continuum, nor do the rivers, the tree and the mountain have defined points at which there is a changeover. The analogy for this would be to go into Paint and draw a series of lines one next to another that shift from (255,0,0) to (255,255,0). Looking at such a band of color, you could tell me that you started at red and went to yellow, and you could probably point out orange to me, but is where you think orange begins the same place that I think orange begins? Do you think you would pick the same place at a glance, every time? And when you have determined where orange begins, will you be able to say, conclusively, looking one pixel to the left, that the line to the left is definitively "red" and not "orange?"

You kinda lost me there. I think I can visualize the transition from the point of view of the rivers/tree/mountain, but what would you see if you were on the plane, and not on the road?

There can be a land transfer from time to time, too, though the land would gradually take on traits in accordance with its new environment. A transition from Mechanus to Elysium is almost certainly out of the question, however - goodness appearing in pure law would move a location into Arcadia first, then Celestia, then Bytopia. It's not the most sudden of transitions. There won't be a crater left over or a town crushed under SURPRISE TOURISM ROCK, though.

Hmmmm, I think I got it. But say the piece to be transfered was a cave in a mountainside. Would the whole mountain be transfered, or would the cave simply vanish and appear in a similiar mountain, or isn't there this kind of information available? (Btw, I meant to say Seven Heavens, I always get the "proper names" wrong )

[afroakuma]

Hmmmm, I think I get it. But wouldn't it make sense for a "larger infinite" to be there encompassing everything? I'm trying to avoid thinking 4E's Elemental Chaos, but I can't think of a better visualization.

Well, that's where the analogy falls off, since the infinite expanses of the planes aren't "lesser" than anything they could be. There aren't any numbers "between the cracks," as it were.

You kinda lost me there. I think I can visualize the transition from the point of view of the rivers/tree/mountain, but what would you see if you were on the plane, and not on the road?

If you're on the plane? So, if you're on Arborea and following the river? You would keep following the river. It might eventually go into a cavern or make a waterfall or flow into a sea, but none of these are necessarily the transition point between the Oceanus on Arborea and the Oceanus on Ysgard. They could be, mind you, but movement on the river as a planar pathway doesn't really jive with movement on the river as a simple waterway. There's a reason competent ferrymen are sought out for such journeys.

Hmmmm, I think I got it. But say the piece to be transfered was a cave in a mountainside. Would the whole mountain be transfered, or would the cave simply vanish and appear in a similiar mountain, or isn't there this kind of information available? (Btw, I meant to say Seven Heavens, I always get the "proper names" wrong )

Depends on a huge variety of factors. A whole mountain moving is certainly within the realm of possibility, but it wouldn't do so just for a cave's worth of change. Heck, a cave probably wouldn't shift either for a cave's worth of change. The Planes aren't that shifty.

[AuraTwilight]

The Ordial Plane is a mysterious place. The Rule of Three and the Unity of Rings both seem to confirm its existence as the Plane of Proof - that which links matter and belief, supplying form to the Outer Planes - yet it has never been conclusively confirmed by planar explorers.

Some believe it may be that outer realm in which Vestiges are trapped, though this is unlikely. Many have conjectured that it might be inhabited by those creatures which call both the Ethereal and the Astral home - completing the trine, if you will. Those creatures certainly aren't telling.

The Ordial Plane, if it does exist, would likely mirror characteristics of the Ethereal and Astral Planes; no layers, just an infinite expanse, and with borders to the Inner and Outer Planes. As the conventional plane (in the sense of being a part of this multiverse) furthest from the Material Plane, it is inherently difficult for Primes to conceive of. This may be why planar travelers have never found it - stumbling across a gate to the Ordial, they may not have been able to recognize the portal for what it was, or even the realm beyond for a different place.

Extra Credit: Homebrew what it's actually like to visit the Ordial Plane, what its planar traits are, etc. :P

Alternative question:

Name and describe your favorite and/or most interesting Demiplane that you know of.

[HunterOfJello]

I just started up a campaign that includes both a Sorcerer and a Psion.

1. I know that arcane magic changes based on which plane an individual happens to be on at the time, but do psionics change also?

2. If psionics do not change, what do you think is the best method to get the player who started up a Sorcerer to not hate me for making this a Planescape game?

[Larkas]

Well, that's where the analogy falls off, since the infinite expanses of the planes aren't "lesser" than anything they could be. There aren't any numbers "between the cracks," as it were.

Okay, so the transitions are like portals and gates on the Outer Planes, just bigger? I think I can get that.

If you're on the plane? So, if you're on Arborea and following the river? You would keep following the river. It might eventually go into a cavern or make a waterfall or flow into a sea, but none of these are necessarily the transition point between the Oceanus on Arborea and the Oceanus on Ysgard. They could be, mind you, but movement on the river as a planar pathway doesn't really jive with movement on the river as a simple waterway. There's a reason competent ferrymen are sought out for such journeys.

Sooooo... If you're in the river, at some point the river-path won't follow the physical river in the plane? I think I can get that too, though it's a bit confusing.

Depends on a huge variety of factors. A whole mountain moving is certainly within the realm of possibility, but it wouldn't do so just for a cave's worth of change. Heck, a cave probably wouldn't shift either for a cave's worth of change. The Planes aren't that shifty.

Hmmmm, fair enough.

[afroakuma]

Extra Credit: Homebrew what it's actually like to visit the Ordial Plane, what its planar traits are, etc. :P

Ah, but that would be telling! I may do it at some point, though.

Alternative question:

Name and describe your favorite and/or most interesting Demiplane that you know of.

Well, the Demiplane of Dread is technically the most fleshed-out of all of them...

The Boundless has an eerie and mysterious quality which I rather like, though I haven't yet found a use for it. Draedenden has a fundamental appeal to me. Dungeonland is of course hilarious and fun. I also like the Demiplane of Time.

Let's go with The Boundless. This is a small demiplane, featuring crystalline isles on a large ocean. Devoid of life, all that's really here is the shore and the way you came. Drinking of the waters of The Boundless heals one on their first visit, which can last any amount of time and yet take no time outside. On the second visit, the waters rejuvenate, restoring some youth, though the realm now feels darker and more ominous. After the second visit, the demiplane seems to "hunt" past tourists in some fashion, with its color pools opening very close to you in your travels through the Ethereal as though to draw you in, and the plane itself seeming to crop up near your location when it would be difficult to avoid it. Nobody who has entered The Boundless a third time has ever emerged. The plane has a strange warden, an immortal woman who gives a few words regarding the plane and offers nothing more.

[afroakuma]

I just started up a campaign that includes both a Sorcerer and a Psion.

1. I know that arcane magic changes based on which plane an individual happens to be on at the time, but do psionics change also?

2. If psionics do not change, what do you think is the best method to get the player who started up a Sorcerer to not hate me for making this a Planescape game?

Psionics don't change, per se, but they can become more difficult to use on the Planes. Certain powerful entities can exert a sort of mental pressure that increases the PP cost of psionic abilities. Similarly, on the Outer Planes, the greater the difference between a psion's alignment and that of the Outer Plane he or she is on, the more it can cost to activate and/or augment.

Don't be afraid to give some planar creatures psionic competencies. In the past, many outsiders had psionic abilities, but as psionics was not a component of 3.5's core rulebooks, psionic monsters did not appear in Core.

[Larkas]

Ah, but that would be telling! I may do it at some point, though.

I always thought that the fun about the Ordial is exactly it NOT being able to be described. Somewhat like... The Far Plane? Nah, their weirdness are too different from one another to be the same place.

[afroakuma]

Okay, so the transitions are like portals and gates on the Outer Planes, just bigger? I think I can get that.

Essentially. It's a vast blending, since what's coming out and what's going in mix in different amounts the further you go, and each border region has its own name and character.

Sooooo... If you're in the river, at some point the river-path won't follow the physical river in the plane? I think I can get that too, though it's a bit confusing.

That's the Planes for you. I'll try to clarify though:

Suppose you can follow the physical river from A to B to C on Arborea, and from D to E to F on Ysgard. You may sail down either part of the river on that plane and just be using it as a river on that plane, or you can sail down the river as a planar pathway. If you do, you're not sailing from A to B to C' while onlookers stand at C (that is to say, there isn't a metaphysical forking going on); instead, you're sailing from A to B to D (at some point, you cross the planar boundary).

[afroakuma]

I always thought that the fun about the Ordial is exactly it NOT being able to be described. Somewhat like... The Far Plane? Nah, their weirdness are too different from one another to be the same place.

The essay that was written about attempts to find the Ordial was marvelous (and at times, very disturbing) but they're definitely not the same place.

[Larkas]

Suppose you can follow the physical river from A to B to C on Arborea, and from D to E to F on Ysgard. You may sail down either part of the river on that plane and just be using it as a river on that plane, or you can sail down the river as a planar pathway. If you do, you're not sailing from A to B to C' while onlookers stand at C (that is to say, there isn't a metaphysical forking going on); instead, you're sailing from A to B to D (at some point, you cross the planar boundary).

Hmmmm, interesting! I think I get it now. Last question, though: can you choose? Or can you, by accident, stumble upon D while trying to get to C? Or both?

[afroakuma]

Hmmmm, interesting! I think I get it now. Last question, though: can you choose? Or can you, by accident, stumble upon D while trying to get to C? Or both?

If you're not a good sailor, you could end up "further" on the river than you wanted to go. Those practiced in navigating the waters can set their course properly.

[Arcanist]

If you're not a good sailor, you could end up "further" on the river than you wanted to go. Those practiced in navigating the waters can set their course properly.

Is it wrong that I feel 1337 for knowing this already? (not really...)

Question: What is the Origin of the Plane of Shadow? In some conflicting stories (more specifically FR) the Plane originated as a Demiplane and slowly expanded outward as it was created by an Arcanist (no, not me...), however in others (Greyhawk) it always was. Can it be assumed that the Realm is older then Greyhawk in terms of age? (not publication date

For bonus points: How would you describe Shadowstuff? I've never actually seen any physical description of it (assuming you can even hold it with your hands) and have only heard that it was a big blob of darkness that appears almost alive (that last line concerns me on that note). No clue where I got this description.

[afroakuma]

Traveling for the next block of time. Will handle any questions left here when I get back (including Arcanist's above).

[Mystra]

I might be able to help with some answers:

1) Both Planescape (IIRC) and 3.5 describe the Elemental Planes as both infinite and bordering other Elemental (or Para-Elemental, or Quasi-Elemental, or Energy) Planes. Hence, where the Water Elemental Plane borders the Air Elemental Planes, you'd have steam. But how can something be both infinite AND border something else?

They have infinite borders, of course. If your anywhere in the ''middle'' of an Elemental Plane, it goes on forever. If you were to pick any random starting point and then travel in any direction you could endlessly travel. From your starting point, it's an infinite distance to the infinite border. Unless you know the 'shortcut' to the border(think like a wormhole). And if you were at the border one side would be the plane your on, and the other side another plane...but the plane would be infinite in all directions.

In fact 'border' might be a misnomer, as it's more like an ''infinite crossing non-point''.

2) The same applies for the Outer Planes in some measure. But there are also River Styx and Oceanus, the Yggdrasil and other things that link stuff. How can you picture, for example, Oceanus passing through Arcadia and Ysgard? Do the shores form a continuum (and, thus, there is a real border, like in the Inner Planes), or does only a tiny fraction of the river exist in both planes (imagine: patch of land-river-patch of land)? Both are somewhat strange propositions!

The rivers and such are ''special'' and no one quite understands how they work. And again the wormhole idea works. You could sail on the River Styx for an infinite time across the infinite Abyss. But only if you know how to access the 'wormhole' can you move to another plane. You might think of the River Styx and such as a ''Permanent Gate''. In short, they are ment to be ''strange''.

3) In Planescape, I remember some locations changing planes because of a shift in alignment. A place in Mechanus that became too Good-aligned could suddenly become part of Elysium. Now, how do that work? Is there a land transfer, or are only buildings and/or features transfered?

It's not clear how it works...again this is a mystery. Land, air and such is transferred. And if you go by the old, old, old Planescape idea: Each, say rock, on a plane is actually a solidified though/idea/emotion/philosophy/etc. So each pebble on the Abyss is say, for example, a madman's thought of slaughtering their family. And then the location changes, each one becomes a new/altered solidified thought/idea/emotion/philosophy/etc. The idea is that a plane is not ''static'' so bits and pieces ''almost'' change location all the time as the solidified thought/idea/emotion/philosophy/etc change. But it takes a large concentration of such thought/idea/emotion/philosophy/etc for the shift to take place.

[Larkas]

Thanks a lot, both of you! However confusing, these answers have been quite informative!