WarframeAlchemyLab ES
Eidolon Shard

Farming plan

Eidolon Shard

Arsenal: Eidolon Shard
Dropped by
Elite Sanctuary Onslaught, Rotation B Rare 8.43 %
Sanctuary Onslaught, Rotation A Rare 7.14 %
Sanctuary Onslaught, Rotation B Rare 7.14 %
Chance of getting it by number of runs
0% 25% 50% 75% 100% 7 15 22 30 37 8 runs · 50% 8 runs · 50% 27 runs · 90% 27 runs · 90%

Each run has a 8.43% chance. The curve is 1−(1−p)ⁿ: there is never a guarantee, only growing confidence.