Thelanis, the Faerie Court is a plane in the cosmology of the Dungeons & Dragons setting of Eberron, commonly nicknamed "The Orrery". Physically similar to Eberron and Lamannia, Thelanis is a realm of rugged natural beauty – primarily lush forests and crystal clear waters. Among the trees rise shadowy spires of enchanting beauty, surrounded by mesmerizing lights that look like dancing lanterns. Phosphorescence gleams on plants and stones, lighting the eternal twilight of the plane, while a multitude of stars twinkle in the sky. Thelanis is Eberron's version of the Plane of Faerie, and thus can also be likened to the Feywild.
- Enhanced Magic: Arcane spells are extended and empowered.
- Flowing Time: For every day spent on thelanis, a week passes on the Material plane. Time lost on Thelanis catches up with the traveler, non-native that spend time on thelanis and then return to the Material plane, may be ravenous if they have not eaten in week as measured by Material plane time, and they may actually grow old or die if they have been a long time on Thelanis. Natives of thelanis are unaffected by this effect.
- Thelanis Inhabitants: Dryad, Eladrin (all), Lillend, Nymph, Satyr, Sprite (all), Triton, Sylph, Petal, Shimmering Swarm, Thorn.
- Coterminous: When Thelanis is coterminous, certain magical areas manifest on Eberron, primarily in wilderness areas but also in groves near civilization. Faerie Rings and Mounds can be found at this time, often accompanied by mysterious lights. These places are points where the boundary between the planes is thin and pasage in either direction can occur. Traveler are wise to avoid the mysterious lights for the natives of Thelanis have been known to lure mortals to their native realm – often with no hostile intent but heedless of the effect that spending time in the Faerie court can have on the natives of Eberron. Arcane spells are extended if they are cast within 300 feet of a ring or mound. Fey creatures are more populous on Eberron at this time. Thelanis is coterminous for seven years every 225 years, when coterminous ends it travels 102 years before becoming remote.
- Remote: When Thelanis is remote, fey creature are fewer and their powers fade (reduced by 1 level). Thelanis is remote for fourteen years every 225 years, when the remote phase ends, it travels 102 years before becoming coterminous.