Planar Architecture for grodog's Current Greyhawk Campaigns

Part of what I'm working toward, by defining and incorporating the forgotten Folio forest into my current Greyhawk campaigns, is to play a more gates-oriented game.  This is one of several campaign concepts on my DMing bucket list, and in this case they appear excerpted here as a cluster of related ideas:

Games/campaigns I'd most like to run, in rough order of my desire:

• gates-driven AD&D campaign starting out at fresh at low level (1st-3rd-ish), where gates are sufficiently common that they drive the entire campaign:  economy, weather, culture, travel, etc. (think The Primal Order meets Stargate meets World of Tiers meets Moorcock's multiverse meets Greyhawk)
• AD&D "Treasure of the Dragon Queen"; I'll have to write it first, of course:  http://www.greyhawkonline.com/grodog/gh_tourneys_dragon_queen.html
• AD&D Greyhawk drowic adaptation of MERP 1e Courts of Ardor campaign (could be played as an evil campaign by drowic PCs or traditional good-ish PCs; could merge with previous gates-driven entry)
• AD&D Abyssal campaign (PCs are a new generation of demons, vying for power amidst the chaos; could combine with gates or drowic ones above); I've slowly been building the framework for an AD&D game where the PCs run demons and explore the mythic geography of the multiverse

In order to play a gates-oriented game, I need to design elements that specifically introduce gates and related magics into the game.  Some of that is easier, some harder.  We'll see how it goes as the games continue, but here's the framework that I've been working up for Oerth's immediate multiversal neighborhood.  I wrote the bulk of this post in response to some discussion in the Greyhawk sub-reddit, in which the user u/P4TR10T_96 asked A Question About the Planes:

Are [the planes] connected to all prime material planes, with the exception of worlds that are explicitly stated to be separated from the rest (Eberron for example)?

but I'd drafted the bulk of the content below in my design journal back on New Year's Day:

This is in your purview to define as the DM. There's not a lot of explicit guidelines on defining your own multiverse(s), but I do list a bunch of resources you can dig into in my two gates/planar articles from Knockspell Magazine:

• https://grodog.blogspot.com/2017/05/the-theory-and-use-of-gates-in-campaign-dungeons.html
• https://grodog.blogspot.com/2017/05/the-theory-and-use-of-gates-in-campaigndungeons-part-2.html

Greenwood's seminal article "Theory and Use of Gates" and the bibliography at the end of part 1 should both be particularly useful for your purposes, I think.

In my current Greyhawk campaigns, I'm boosting the gates/planar aspect of play through a few different methods:

1. I'm leveraging alternate Prime Material Planes to Oerth, in a Norse-like model with some known/planarly "nearby" worlds as "sister worlds." *
2. Adding more gates, magical pools, free-standing portals, and such into the mix early in the campaign, so that the PCs grow in power with these as baseline "givens" in the game world/setting and in their campaign adventures. NPCs dwarves will be encountered that are from "Nidavellier" for example (or whatever name I settle on for that place).
3. Adding some more spells (see my 2nd KS article above) into the mix, along with some planar-related magic items that will make planar-related "stuff" more accessible for the PCs

* The list of sister worlds is not fully-baked yet, but will likely end up looking something like this:

1. Oerth/Greyhawk - home plane for the current batch of PCs
2. Mendenein - my homebrew campaign that is interleaved with Greyhawk and is its "closest" sister world: many permanent portals exist between the two planes, including some that are always open and allow cross-planar trade, for example; if you're curious, you can see some of my maps in on Dragonsfoot at https://www.dragonsfoot.org/forums/viewtopic.php?p=2025364#p2025364
3. Hyperborea - the plane for Astonishing Swordsmen & Sorcerers of Hyperborea, from my friend Jeff Talanian's publishing company Northwind Adventures: https://www.hyperborea.tv/store/c1/Featured_Products.html
4. "Jotunheim" - in some form or other: the homeland of giants, which will likely have multiple layers/sub-planes associated with it (Muspelheim, for example)
5. "Faerie" - in some form or other - the homeland of elves and fey; probably won't be an alternate Prime, but more like the Shadow Plane or Ethereal, in that it's accessible from many Primes (via regio-like zones from Ars Magica/Robert Holdstock's Mythago Wood)
6. "Nidavellier" - in some form or other: the homeland for dwarves; connects to Oerth in the Underdark
7. Arabian Nights desert plane: more Dune, The Eight, Rodney Matthews, Thieves World and Tattooine than Dark Sun or Al-Qadim
8. Archipelagos and Islands watery plane: Blue Planet meets the Greek Aegean; a likely homeworld for the Oeridians, perhaps
9. Other: various other settings will be linked and in the mix, but not as "close" and therefore not as easily accessible as these planes. The other settings will include Avremier (from Mothshade Concepts), Helveczia (from u/GaborLux), Averoigne (from CAS, and perhaps other of his worlds like Zothique), the Old World (from 1e Warhammer FRPG), perhaps the Known World (from B/X), and the usual smorgasbord from fiction (Moorock, Leiber, REH, etc.)

In addition to what I'd posted in the reddit, there are some other planar decisions that I'm still working through, too:

• The Rhenne home plane of Rhôp will be in the mix as well many of Greyhawk's famous and infamous demi-planes and Fading Lands.  I don't plan to place Rhôp planarly "close" to Oerth, and am pondering that it may have been destroyed (or presumed destroyed, with the Rhenee always holding out hope that it survives still---a way to reverse-exploit their chicanery against them, perhaps:  Rhôp being the one thing you can reliably gull the Rhenne with), making the Rhenee into planar refugees/expats of a sort.  I sort of envision them having fled a planar rift, so portions of Rhôp may survive as fragments in the Ethereal, Astral, Shadow/etc. planes....
• I've sketched out a simple planar relationship diagram over Memorial Day weekend:
   
  

  

  Oerth and Mendenein Prime-Planar Environs

  
  I'm not sure that it really reflects the planar relationships that I want I to define yet, and since I'm still thinking of a Tree of Life structure for the planes too, that may necessitate bumping one or more up to the level of "primary Primes" perhaps.
• I have another similar diagram and/or notes that take the planar concepts from Dragon #73 and leverage 2d4 joined into a pointier six-sider as the basis for that planar structure (no doubt inspired by Steve Marsh's d4 structure proposed in Dragon #73), but haven't refound them yet.  That's more important for the Inner vs. Prime planes, so not super-necessary, yet.

More to come as it percolates into play! :D

Allan.