Luck

Luck is a status effect which increases luck.

Effect
Adds 1 × level to attribute, making loot table entries with a high   score more likely, and entries with negative   less likely. It also increases the chances of  occurring. Currently, only fishing uses. The new weight of each entry is. Negative levels decrease luck.

Immune mobs
No mobs are immune to Luck. It is not known if it actually affects anything they do, though.