WarframeAlchemyLab ES
Melee Riven Mod

Farming plan

Melee Riven Mod

Arsenal: Melee Riven Mod
Dropped by
Enter Nihil's Oubliette, Rotation C Common 35 %
Sorties Rare 9.8 %
The Descendia: Uncommon Rewards (Steel Path) Rare 7.14 %
Chance of getting it by number of runs
0% 25% 50% 75% 100% 2 4 5 7 9 2 runs · 50% 2 runs · 50% 6 runs · 90% 6 runs · 90%

Each run has a 35% chance. The curve is 1−(1−p)ⁿ: there is never a guarantee, only growing confidence.