Luck is valuable when killing Named creatures and bosses as it increases the chances that you will receive Named loot as well as any rare materials and jewelry. Our item attributes (STR, CON, INT etc.) and perks (e.g. Keen, Refreshing Ward, Skinning Luck etc.) roll separately from the general chance to drop loot, and therefore, luck is not a factor in determining the rarity of a non-named item. Players with high luck stats have a much better chance of earning exclusive rare drops, like Named Weapons and Trophy components.