Lootbox Calculator

The calculator runs a Monte Carlo simulation: it repeats the lootbox opening process thousands of times and collects statistics on how many attempts it took to get each item.

Fixed Weights - each opening is independent. Every item has a fixed probability equal to its weight divided by the total weight of all items. The pool never changes.

Remove on Drop - once an item drops, it is removed from the pool. Remaining items' probabilities increase with each opening. This guarantees all items are obtained in a finite number of attempts equal to the item count at minimum.

Pity System - a selected item's weight increases by a set amount every N failed attempts. The weights of other items stay unchanged, but their probability decreases as the total weight sum grows.

Hard Pity - one item can be marked as guaranteed: it will always drop on a specific attempt number, regardless of weights. All other attempts follow normal weighted probability. Only one item can have a guarantee at a time.

Results show the average (mean attempts across all runs), median (50% of players get the item by this attempt), 95th percentile (how many attempts the unluckiest 5% need), and the min/max range.