I'm currently working on a homebrew world for a campaign of mine, which is currently on hold indefinitely, so there's no time pressure.
Overall design intent:
- I don't want my world to be a clone of the general world and lore of D&D (including the Forgotten Realms & the planar cosmology), with the only difference being the Material Plane.
- I'm not entirely content with the planar cosmology and pantheons in the Forgotten Realms and other existing settings (Eberron, etc).
Since I personally don't like the Astral Plane in particular, I'm thinking about outright removing it from my world.
However, the DMG states on page 43 on "The Planes":
At minimum, most D&D campaigns require these elements:
- A way of getting from one plane to another
- A way for spells and monsters that use the Astral Plane and the Ethereal Plane to function
Obviously, I don't have to adhere to these guidelines. However, I'm aware that a number of spells, creatures, magical items and other things in 5e directly refer to the Astral Plane. Miniman's answer to the question What are all the ways a player can get to the Astral Plane? lists quite a few of these.
Naturally, spells (like Astral Projection), creatures (including playable races like Gith) or magical objects that refer to the Astral Plane simply don't exist (in unmodified form) in this campaign. I'd homebrew something for what happens when you put e.g. two Bags of Holding into each other.
I also know that the Astral Plane can be used as a means of travelling between different worlds, using the color pools located on it. I'm thinking about implementing a Yggdrasil-style World Tree in my world, which would assume this job.
Are there any other ramifications as a result of not having an Astral Plane in a 5e campaign setting?