Luck (LUK) is a stat used in the Yggdra Union subseries. LUK reduces the chance of being hit by Critical Hits, while also increasing the probability of scoring one. In order to get a boss character to drop the item they are using, the LUK of the unit who reduces their morale to zero must be equal to or greater than the LUK of the boss. Luck also influences how often the head can activate special abilities (typically from an equipped item).