The Reductus Sector is home to Phobian, the Adeptus Astartes Homeworld of the Dark Hunters chapter. The sector is also the last known location of the Knights of Gryphonne chapter, who were reduced to a fleet-based organisation after the destruction of their homeworld elsewhere in the segmentum. Worlds in the Reductus Sector were assaulted by Hive Fleet Leviathan, including the now-lifeless Knight World of Rapture.
Worlds known to exist within the Reductus Sector include:
- 1: Codex: Space Marines (5th Edition), p. 30
- 2: Codex: Imperial Guard (5th Edition), p. 26
- 3: Codex: Imperial Knights (6th Edition), p. 11