WarframeAlchemyLab ES
Rage

Farming plan

Rage

Arsenal: Rage
Dropped by
Operation: Orphix Venom, Rotation C Uncommon 14.29 %
Eidolon Hydrolyst Uncommon 13.76 %
Eidolon Hydrolyst (Capture) Uncommon 12.74 %
Operation: Orphix Venom, Rotation A Rare 6.52 %
Deimos Jugulus Rex Rare 4.42 %
Derelict Vault Rare 4.17 %
The Descendia: Infernum 20 Triple Arcane Rewards Rare 3.7 %
Chroma Uncommon 0.6 %
Commandeered Ember Prime Uncommon 0.6 %
Commandeered Protea Prime Uncommon 0.6 %
Commandeered Trinity Prime Uncommon 0.6 %
Ember Specter Uncommon 0.6 %
Chance of getting it by number of runs
0% 25% 50% 75% 100% 4 8 13 17 21 5 runs · 50% 5 runs · 50% 15 runs · 90% 15 runs · 90%

Each run has a 14.29% chance. The curve is 1−(1−p)ⁿ: there is never a guarantee, only growing confidence.