- Dragonshards fuel the world’s magic. Eberron shards (from the earth) store magic; Khyber shards (from below) bind elementals and spirits; Siberys shards (fallen from the sky’s ring) empower dragonmarks.
- Thirteen planes orbit Eberron, coming closer and drifting away on long cycles. Where one touches the world you get a manifest zone: a forest that’s always twilight, a city that’s easier to build tall. Dal Quor is the plane of dreams. Thelanis is the realm of the fey.
- Getting around: the lightning rail (Orien), elemental airships (Lyrandar, very expensive), Orien teleportation (rare and pricey), and Sivis speaking stones for messages.
- Warforged: living constructs built by House Cannith as soldiers. Free citizens since Thronehold, though many people still treat them as property.
- The Draconic Prophecy: the dragons believe the future is written in the stars, the earth and in dragonmarks themselves. Scholars and cranks argue about it. (Your campaign is named after it.)
From the Eberron Player Primer. Public knowledge and rumour only.