Pick an item and a number of rolls. The maths assumes independent rolls at the listed base rate — the same assumption the in-game odds display uses. Rates come from the game's own feed lines; only rolls we have actually read appear here, and the list grows with every check.
Luck multipliers (potions, the +3 group bonus, Meteor Shower's +50%) shift the effective rate above these base figures, so treat the results as a floor rather than a promise. The printed 1-in-N rates themselves never change — luck works on top of them.
0.00%
chance of seeing Entropy Well at least once in 100 rolls
Hitting the average does not mean the item is guaranteed — at that point you are only about 63% likely to have it. Plan against the confidence rows instead.
FAQ
For a 1-in-N item the chance of missing it once is 1 − 1/N, so after n rolls the chance of having seen it at least once is 1 − (1 − 1/N)^n. The table shows the roll counts for 50%, 90% and 99% so you can plan against a real target.
No. At the average you are only around 63% likely to have seen it once. That is why the table leads with the 99% column — the number players actually want.
Because only two rates have been cleanly read from footage so far (Entropy Well at 1 in 2.58T and Rift Devourer at 1 in 58B). Every future feed read adds an entry — blank stays blank until then.