Drop rate

The drop rate of an item is the frequency at which at which defeating an enemy, opening a treasure coffer, completing a FATE, or any other random acquisition method is expected to yield the item. Drop rates can vary widely, with some items being guaranteed and others being extremely rare drops.

For example, if the drop rate of an item from an enemy is 20%, then players will on average receive one of the item per five kills.

All drop rates are server-side, not provided by Square Enix, and thus must be determined from experimentation. Like with other sampling methods in statistics, experimentally determined drop rates are more likely to reflect the true drop rate if the sample size is larger. This site contains crowd-sourced drop rate data of items from a variety of random sources.