Mirror Planes

[Ardantis]

I missed out on 4e.

My friends and I cut our teeth on 3e and 3.5e in high school and college, respectively, and we all liked it so much (especially character building) that we kept it through all of 4e's time. It wasn't until 5e that any of us decided it was worth upgrading.

So, it turns out we missed a few things, welcome additions to 5e like quality nonmagical healing and more effective martial control.

And the mirror planes.

Now, none of the groups I ever played in got up to the level of having Great Wheel adventures, exploring and combatting the external manifestation of our alignments, but we shied away from the adjacent planes because they were so uninteresting- the positive and negative energy planes, the plane of shadow, the ethereal plane...

The elemental planes were so confusing. There was an elemental plane of wood, for cripe's sake!

I owned the Manual of the Planes 3.5. I read it and was enraptured by the exotic locales that existed in the far reaches of the planes- but their denizens were too dangerous for us to go anywhere near!

Now I read in 5e Cosmology that 4e invented exotic adjacent worlds, "mirror planes" which were just as lushly well-thought-out as the Great Wheel planes, yet were reachable at comparatively low levels and were full of creatures level-appropriate for parties below lvl 10. Sweet!

1. How do they work/what are the basics of the Feywild and the Shadowfell? How are they related to alignment, how do they connect to the Prime Material Plane, and how do you get to them (before Plane Shift?)

2. How are they related to the other adjacent planes, the ethereal, the astral, and the elemental? What is the elemental chaos?

3. Are the Feywild and the Shadowfell connected to the Great Wheel in 5e by any means other than the Astral Plane?

4. What else did I miss in 4e that I'm going to be seeing in 5e?

[ImSAMazing]

I missed out on 4e.

My friends and I cut our teeth on 3e and 3.5e in high school and college, respectively, and we all liked it so much (especially character building) that we kept it through all of 4e's time. It wasn't until 5e that any of us decided it was worth upgrading.

So, it turns out we missed a few things, welcome additions to 5e like quality nonmagical healing and more effective martial control.

And the mirror planes.

Now, none of the groups I ever played in got up to the level of having Great Wheel adventures, exploring and combatting the external manifestation of our alignments, but we shied away from the adjacent planes because they were so uninteresting- the positive and negative energy planes, the plane of shadow, the ethereal plane...

The elemental planes were so confusing. There was an elemental plane of wood, for cripe's sake!

I owned the Manual of the Planes 3.5. I read it and was enraptured by the exotic locales that existed in the far reaches of the planes- but their denizens were too dangerous for us to go anywhere near!

Now I read in 5e Cosmology that 4e invented exotic adjacent worlds, "mirror planes" which were just as lushly well-thought-out as the Great Wheel planes, yet were reachable at comparatively low levels and were full of creatures level-appropriate for parties below lvl 10. Sweet!

1. How do they work/what are the basics of the Feywild and the Shadowfell? How are they related to alignment, how do they connect to the Prime Material Plane, and how do you get to them (before Plane Shift?)

2. How are they related to the other adjacent planes, the ethereal, the astral, and the elemental? What is the elemental chaos?

3. Are the Feywild and the Shadowfell connected to the Great Wheel in 5e by any means other than the Astral Plane?

4. What else did I miss in 4e that I'm going to be seeing in 5e?
1. Sometimes the Feywild/Shadowfell are almost identical with the exact same location on the Material Plane. That is a place where a portal COULD open.
2. Feywild and Shadowfell are copies of the Material Plane, except the creatures and the buildings on it. The Ethereal does overlap it I think. The Astral Plane is the same in every plane, and it isn't really connected with the elemental planes. Elemental Chaos is the middle of the 4 elemental planes. All kind of elementals live there.
3. Think not.
4. That every plane that isn't elemental, shadowfell, ethereal, astral, material and feywild has a few special options. Read the DMG and the page for the plane for exact info. For example:
Mechanus has the trait that every time someone deals damage, the damage is ALWAYS average. So 1d10+5 makes 10 damage. You dont have to roll anything.

[Vogonjeltz]

1. How do they work/what are the basics of the Feywild and the Shadowfell? How are they related to alignment, how do they connect to the Prime Material Plane, and how do you get to them (before Plane Shift?)

2. How are they related to the other adjacent planes, the ethereal, the astral, and the elemental? What is the elemental chaos?

3. Are the Feywild and the Shadowfell connected to the Great Wheel in 5e by any means other than the Astral Plane?

4. What else did I miss in 4e that I'm going to be seeing in 5e?

The beauty of 5e is that you get to (if you want) decide the answers to all of these things, so please don't feel constrained by the written answers. You can (and maybe should) try to deviate such that everything feels 'right' for your campaign.

That being said, the 'standard' answers are:

1. Both exist in parallel with the material plane. Think of the show sliders (google is your friend if you haven't seen it) with alternate dimensions sharing the same space. The lands are similar in layout if not in content. The short answer for planar travel is: portals, in the DMG these are called Fey crossings and Shadow crossings, which may only open infrequently (think of the musical Brigadoon where the mists allowed travel to the town once every hundred years or so, but time passed differently there).

2. They should be similar in layout, but different in content. i.e. A volcano on the material plane is a giant crystal in the feywild, and so forth. Feywild is a majesty of nature/shiny-happy-people place, Shadowfell is a drab, colorless, warped place.

3. One thing to note about the great wheel is that it's more like a drawing of the metaphysical and philosophical concepts, not an actual thing one can see. Astral and Ethereal planes are transitive, used for, well, transit, to other planes of existence. One need not enter any other plane to reach the Feywild or the Shadowfell.

[Ardantis]

Is the Elemental Chaos a barrier between the Inner planes and the Outer?

[Naanomi]

Not normally, the elemental and outer planes are on 'opposite ends' of the cosmos and done have a direct barrier or transitive plane between them

Also note this edition pulled the energy planes out of the inner planes to their own place (like they were in 1e), and the shadow fell/feywild are linked to the energy planes, at least indirectly

[Vogonjeltz]

Is the Elemental Chaos a barrier between the Inner planes and the Outer?

No, the elemental chaos is part of the inner planes (i.e. the elemental planes), it's the space between them where various elements are mixed. It's also totally inhospitable to PC life, so other than being some vaguely interesting hooks, it's improbable that the PCs would know or care about it because if they find themselves there, it's either with DM fiat protection, or they're dead shortly after.

You might be interested in an alternative cosmology, wherein all the planes are part of the material plane and accessible from it simply by traveling (albeit the journey would probably be extraordinary).

[Naanomi]

You might be interested in an alternative cosmology, wherein all the planes are part of the material plane and accessible from it simply by traveling (albeit the journey would probably be extraordinary).
Those are fun, a campaign I played in as a kid had a very detailed cosmology set up with the material plane in the 'middle' of the elemental planes (fire was south and so on); the upper planes were above the world, and the lower planes were underneath; with the sun and moon being positive and negative energy planes. Astral and ethereal were still separate though.