Luck check
From Arkham Horror Wiki
The Luck check is a type of Skill check typically presented by encounter cards. It represents a test of the Investigator's innate luck.
A Luck check uses the value of the Investigator's Luck skill, plus any adjustments that the Investigator may receive from skill cards, allies, and Mythos card effects, plus any adjustment specified by this specific check. Unless otherwise specified, a single success is enough to pass the check.
