I'm basically adopting this idea for my Planescape 4e Game.
In fact, I've managed to include all the old 2e planes in my 4e mock-up and relate most of them to existing 4e planes. Only really had to add new stuff for the Mechanus/Elysium/Celestia trifecta, which isn't TOO surprising, given (especially early) 4e's focus on the places in need of beating up, rather than the places with more subtle/nonexistent threats.
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PLANES
You can choose a planar origin instead of/in addition to a
Faction background. You can still only gain the benefit of one background, but planar origins are also prerequisites for feats, PPs, EDs, etc.
The City of Doors
Sigil is the Crossroads of the Multiverse, where all realities converge.
Sigil Background: You’ve grown up in the alleys and politics of the City of Doors, so you know your way around a few different realities.
Associated Skills: Bluff, History, Streetwise
Benefit: +1 to all skill checks when you are in Sigil.
The Mortal World
The mortal world was created by the gods, who also created the races therein. Largely considered a backwater bumpkin-ville from Sigil’s perspective.
Mortal Background: You know the layout and history and environment of the mortal world
Associated Skills: Dungeoneering, History, Nature
Benefit: +1 to all skill checks when you are on the Mortal World.
The Hinterlands
A place of seeming mortal-world normality where things quickly get weird; a sort of all-in-everything of the planes. From here, Sigil can be seen floating above the Spire, and approaching the Spire has the effect of nullifying great powers.
The Outlands: A place within the Hinterlands that strips power from the powerful, rendering even the gods little more than mortals, and nullifying the most powerful of magick.
Hinterlands Background: You’re handy in obscure and bizarre natural environments.
Associated Skills: Arcana, Endurance, Nature
Benefit: +1 to all skill checks when you are in the Hinterlands.
The Astral Sea
The “place between the Planes,” a silver void above the Mortal World. The realms of the gods often float about in this place.
Astral Sea Background: You know your way around an astral skiff.
Associated Skills: History, Insight, Religion
Benefit: +1 to all skill checks when you are in the Astral Sea.
The Elemental Chaos (“Limbo”)
The “place before the Planes,” a roiling soup of elemental matter where creation and destruction are entwined.
Ysgard: The place of the Creation of the World, where rivers of fire support oceans of earth, and death is only temporary.
Dischordia: A place in constant flux, a map that re-arranges itself at will, that seems to enjoy frustrating people.
Limbo Background: A random assortment of elements is your home field
Associated Skills: Athletics, Endurance, History
Benefit: +1 to all skill checks when you are in the Elemental Chaos.
The Feywild (“Arborea”)
A plane of rampant nature and arcane magic, where everything is charged with the energies of the fey spirits that dwell within, and the primal wildness of the place.
The Beastlands: A place of primal might where all creatures become savage animals, living free and natural and independent.
Pangea: A place of elemental primitives, where intelligence and technology are destroyed, and raw martial nature reigns supreme.
Arborea Background: You know your Oak from your Yew.
Associated Skills: Arcana, Nature, Stealth
Benefit: +1 to all skill checks when you are in the Feywild.
The Shadowfell (“The Gray Waste”)
A plane of death and shadow magic, where souls go to receive their final judgement. A dark mirror of other worlds, distorted and abstract.
Carceri: A place where the truly hateful beings are locked away, under the auspices of immortal spirits that keep them caged.
Nether: An endless, frozen, muddy graveyard of undead that spontaneously animate.
Shadowfell Background: You’ve been around the dead. You’re not that impressed.
Associated Skills: Heal, History, Stealth
Benefit: +1 to all skill checks when you are in the Shadowfell.
The Abyss
A cancer at the heart of the Elemental Chaos, constantly sucking at the world above. Infinite and evil, it spawns horrors whose only interest is destruction.
Pandemonium: A place of madness and panic, where mental illness is born.
Perdition: A place of selfish apathy, where instant gratification is the norm.
Abyssal Background: Screaming demons and alien suffering is your daily commute.
Associated Skills: Athletics, Dungeoneering, Endurance
Benefit: +1 to all skill checks when you are in the Abyss.
The Nine Hells
A deep tear in the Astral Sea, a place for endless diabolical machinations, and a resting place of the god Asmodeus as he schemes for multiversal dominance.
Gehenna: Floating “moons” of the Nine Hells, four volcanic slopes that produce a suffering grind.
Sheol: A place sloping “downhill,” a gravitational well around the Nine Hells, where the natives are in a constant state of cold-war.
Baatorian Background: You see schemes and plots and machinations daily.
Associated Skills: Bluff, Insight, Intimidate
Benefit: +1 to all skill checks when you are in the Nine Hells.
Mechanus
A world at the far end of the Astral Sea, where a seal protects against the Far Realm. A great calculating engine, home of various deities of law and order that seek to understand and puzzle out the nature of the multiverse.
Acheron: An astreroid-belt-like plane filled with geometric shapes, whose armies constantly battle in a never-ending exercise of order and obedience.
Purgatory: An infinite spiral staircase, said to reach all the way to the mortal world below, of folks who dedicate themselves to their work over everything.
Mechanus Background: The whirling gears of the multiverse are yours to traverse.
Associated Skills: Arcana, Diplomacy, History
Benefit: +1 to all skill checks when you are in the Mechanus.
Celestia
A great mountain in the Astral Sea that stretches higher than infinity, challenging the truly pure and good to climb it. A place of justice and crusading goodness.
Arcadia: Fields before the mountain, where folks pursue a life of virtuous order, hoping to be seen as good and useful citizens.
K’un Lun: A mountain range where peaceful people seek inner perfection.
Celestia Background: Shining virtue is rather old hat to you.
Associated Skills: Diplomacy, Insight, Intimidate
Benefit: +1 to all skill checks when you are in Celestia.
Elysium
A vast field in the Astral Sea full of light and color, where the innocent and virtuous go for their afterlife reward.
Bytopia: A peaceful, rural place of rugged wilderness and fraternal cooperation.
Avalon: Misty islands in the sea that reward the virtuous with rest, and conceal powerful good magic.
Elysium Background: Idyllic beauty and peace are your home life.
Associated Skills: Diplomacy, Heal, Insight
Benefit: +1 to all skill checks when you are in Elysium.
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