In Minecraft’s 1.9 update, Luck is a somewhat mysterious stat that isn’t encountered often, if at all, in Survival Mode.

Bestowed on players via Potions of Luck and Arrows of Luck, the luck effect improves the chances of receiving better loot from loot chests within generated structures such as Mineshafts, temples, strongholds, and ruins.
Since Potions of Luck cannot be brewed and Arrows of Luck cannot be obtained in Survival Mode and require a console command or access to the Creative Mode inventory, players are left somewhat stuck.
Players will be notified via a status effect indicator on their inventory screen when the luck effect is active, signified by a lucky Four-Leaf Clover.
Minecraft: Obtaining luck items via console commands
It is also important to remember when it comes to the luck status in Minecraft that only players are affected. Mobs hit with Splash Potions or Arrows of luck will not be influenced by the status. They technically aren’t immune to luck, but it simply does not alter them in any way.
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