Rubedo farming guide
Phobos — Zeugma (Dark Sector Survival)
The wiki cites roughly 250 Rubedo per 5 minutes here on a signature Rubedo planet; Rubedo drops from the enemies you kill, so a Nekros loot squad and a Resource Drop Booster raise the yield further.
Boosters help: this spot relies on enemy drop tables.
Void — Ani (Survival, Steel Path)
The wiki recommends Orokin Void endless missions for 1,000+ Rubedo per 20 minutes; Ani is a standard Void Survival for that squad farm, and since Rubedo is an enemy drop the Steel Path passive and a Resource Drop Booster compound it.
Boosters help: this spot relies on enemy drop tables.
Early game
Zeugma on Phobos (Dark Sector Survival) is among the best Rubedo spots at any gear level — the wiki cites roughly 250 Rubedo per 5 minutes there, and Phobos is one of Rubedo’s two signature planets. Rubedo drops from the enemies you kill, so a Nekros loot squad and a Resource Drop Booster raise the yield on top of the Dark Sector’s resource-chance bonus.
Mid & late game
The wiki’s general endgame advice is simply “run Void Survival or Defense” — it cites over 1,000 Rubedo per 20 minutes from Orokin Void endless missions. Ani (Survival, Steel Path) is a standard Void node for putting that into practice with a squad. Since Rubedo is a common enemy drop, the Steel Path passive, a Resource Drop Booster and a loot frame (Nekros/Khora) all stack — and the longer the run, the more enemies you clear.