# Rng Still Has To Obey Statistics...but What Are They?

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So some people may be aware DE is using 'loot rarity' as part of the drop tables; i.e. whatever they decide is 'rare' goes in the 'rare' drop percentage and is diluted, same with the other categories 'uncommon' and 'common.'

Then here's some theorycrafting on drop rates...let's take Tranquil Cleave.

Frontier Butcher - rare drops include Flow, Tranquil Cleave, and Neurode, and presumably has no chance to drop 'nothing' within the rare category; this gives us 2.5% divided by 3 items = 0.83% to drop Tranquil Cleave.

Now statistics. Binomial distribution. The chance of getting at least 1 Tranquil Cleave given x butchers killed.

For 100 butchers: 1 - (chance of getting 0 Tranquil Cleaves) = (Chance of at least 1)

1 - 0.9916^100 = 0.57 or 57% chance

For 200: 1 - 0.9916^200 = 0.82 or 82% chance

For 300: 1 - 0.9916^300 = 0.92 or 92% chance

The chance you would go on a 300 butcher kill streak without getting the mod is fairly unlikely. But that's assuming the drop table is rolled every time it is killed, or no other hokey drop mechanics are at play.

Now the test: the stats indicate a 4 man Nekros team of flux rifles/swords should, in theory, be able to roll a butcher ~7 times on average, assuming only half the butchers get cut in half, and accounting for only 90% desecrate table roll (but assuming desecrate spam gets every butcher). Meaning on any given survival with...say...15 butchers, they'd roll about 100 of them. Which would make farming these trivially easy (3 or so runs with only 8% chance not to get one).

But is this truth? I'm simply curious. Any farmers/stat collectors can provide evidence to refute or confirm this?

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well, 2,5 % of rare mod is pretty high i think. For my experience, i get 1-2 rare mods every 1000 kills. That means the rare mod drop is around 0,15%. And I´m sure, not all mods of the same pool have the same chance to drop. One example is Ruk, only have 2 mods in his Uncommon pool, but how many shootgun savvy people get before he drops Shattering storm?

Edited by Superkoco