Radiance stood at the border between the Elemental Plane of Fire and the Positive Energy plane. It was an extremely beautiful and overwhelmingly bright place, whose constant luminosity threatened to blind anyone who stared for too long.
Along the inner side of the crystal sphere of Realmspace, there were numerous portals to Radiance that ranged between a few yards and hundreds of miles in diameter, that appeared at the dots and dashes of the strange writings that were marked on the surface of the sphere. These brilliant portals, thousands of miles apart from each other on the sphere's surface, were seen from the inhabitants of all the planets as stars and constellations.
Although Radiance was highly destructive to creatures and spelljammers that dared enter it, portals through the sphere could be safely created on top of a star-opening, temporarily superseding it. For an inhabitant on one of the planets, that particular star would seem to disappear for a few minutes and then reappear.
The plane was as hot as the Plane of Fire, so unprotected flammable materials would burst into flames within seconds. Liquids also boiled away into superheated steam. Not even magic items were completely immune to the raw energy of the place. Creatures that lacked fire resistance needed magical protection from spells such as protection from energy or items such as rings of fire resistance. The atmosphere, however, was breathable.
Near the boundary with the Quasi-Elemental Plane of Lightning, multicolored storms could throw creatures enormous distances away. A small island known as the Refuge of Color was the only naturally occurring solid ground on the plane.
The main reason for visitors to go to Radiance was the Heart of Light, a mysterious tower of blue light that stood near the boundary with the Positive Energy Plane. It was a place where injuries and wounds healed at a rapid pace, whose origins were unknown.
The Plane of Radiance had few native creatures. It was inhabited by radiance quasi-elementals, radiant mephits, darklights, scile, and varisoh. Most natives tended to be solitary thinkers and philosophers.
- Jeff Grubb (July 1987). Manual of the Planes 1st edition. (TSR), p. 12. ISBN 0880383992.
- Bruce R. Cordell (1998). A Guide to the Ethereal Plane. Edited by Michele Carter, Keith Francis Strohm. (TSR, Inc.), p. 20. ISBN 0-7869-1205-7.
- Jeff Grubb (April 1987). “Plane Speaking: Tuning in to the Outer Planes”. In Roger E. Moore ed. Dragon #120 (TSR, Inc.), pp. 42–43.
- Monte Cook and William W. Connors (December 7, 1998). The Inner Planes. Edited by Michele Carter and Ray Vallese. (TSR, Inc.), pp. 100–103. ISBN 0-7869-0736-3.
- Jeff Grubb, Bruce R. Cordell, David Noonan (September 2001). Manual of the Planes 3rd edition. (Wizards of the Coast), p. 68. ISBN 0-7869-1850-8.
- Bennet Marks (July 2004). “The Limitless Light: A Tour of the Plane of Radiance”. In Matthew Sernett ed. Dragon #321 (Paizo Publishing), pp. 64–68.
- Monte Cook and William W. Connors (December 7, 1998). The Inner Planes. Edited by Michele Carter and Ray Vallese. (TSR, Inc.), p. 9. ISBN 0-7869-0736-3.
- Dale "slade" Henson (April 1991). Realmspace. Edited by Gary L. Thomas, Karen S. Boomgarden. (TSR, Inc), pp. 3–4. ISBN 1-56076-052-4.
- Jeff Grubb (July 1987). Manual of the Planes 1st edition. (TSR), pp. 55–56. ISBN 0880383992.
- David "Zeb" Cook (1994). Planescape Campaign Setting, A DM Guide to the Planes. Edited by David Wise. (TSR, Inc), p. 35. ISBN 978-1560768340.
- Monte Cook, ed. (1998). Monstrous Compendium Planescape Appendix III. Edited by Michele Carter and Ray Vallese. (TSR, Inc.), pp. 11, 84. ISBN 0-7869-0751-7.
Prime Material plane • Feywild • Shadowfell • Fugue Plane
Transitive Planes: Astral Plane • Ethereal plane
Inner Planes: Elemental Plane of Air • Elemental Plane of Water • Elemental Plane of Earth • Elemental Plane of Fire • Elemental Chaos
Para-Elemental Planes: Frostfell • Swamp of Oblivion • Fountains of Creation • Great Conflagration
Quasi-Elemental Planes: Lightning • Radiance • Minerals • Steam • Vacuum • Ash • Dust • Salt
Outer Planes: Arcadia • Mount Celestia • Bytopia • Elysium • Beastlands • Arborea • Ysgard • Limbo •
Pandemonium • Abyss (Layers) • Carceri • Hades • Gehenna • Nine Hells • Acheron • Mechanus
Energy planes: Positive Energy plane • Negative Energy plane
Planar Pathways: Infinite Staircase • Oceanus • Mount Olympus • Styx • Yggdrasil
Prime Material plane • Cynosure • Fugue Plane
Transitive Planes: Astral Plane • Ethereal plane • Plane of Shadow • Spirit World
Celestial Outer Planes: Arvandor • Brightwater • Dwarfhome • Dweomerheart • Gates of the Moon • Golden Hills • Green Fields • House of Knowledge • House of the Triad
Fiendish Outer Planes: Abyss (Layers) • Barrens of Doom and Despair • Blood Rift • Clangor • Deep Caverns • Demonweb Pits • Fated Depths • Fury's Heart • Hammergrim • Nine Hells • Nishrek • Supreme Throne
Neutral Outer Planes: Dragon Eyrie • Heliopolis • House of Nature • Jotunheim • Warrior's Rest
Inner Planes: Elemental Plane of Air • Elemental Plane of Earth • Elemental Plane of Fire • Elemental Plane of Water • Positive Energy plane • Negative Energy plane
Planar Pathways: Infinite Staircase • River of Blood • World Tree
Prime Material plane
Fundamental planes: Astral Sea • Elemental Chaos
Astral dominions: Arvandor • Banehold • Celestia • Cynosure • Deep Wilds • Demonweb Pits • Dismal Caverns • Dwarfhome • Eternal Sun • Fugue Plane • Gates of the Moon • Green Fields • House of Knowledge • Nine Hells • Nishrek • Supreme Throne • Towers of Night • Tu'narath • Warrior's Rest
Elemental realms: Abyss (Layers) • City of Brass • Cresting Spires • Fimbulwinter • Hidden Realm • Muspelheim • Root Hold • Sky Home • Steading • Thraotor • Undying Pyre • Zerthadlun
Parallel planes: Feywild • Shadowfell
Anomalous planes: Far Realm