Loot Case adds craftable loot box blocks. Place one, right-click it, and watch an animated strip of items scroll past a pointer. After about 12 seconds it slows down and stops on your reward.
There are four tiers: Basic, Iron, Gold, and Diamond. The Basic case can give almost any item in the game, including items added by other installed mods. The Iron, Gold, and Diamond cases are pickier: each one only rolls items that are actually crafted using that material, so the Diamond case only offers items whose recipe uses a diamond somewhere, and the same logic applies to Iron and Gold.
Better items (tools, weapons, armor, and other unique items) show up more often than common filler items like sticks or dirt. Stackable rewards can also come out in a stack of one to three instead of always just one.
Crafting
The Basic Loot Case is made from gold ingots, diamonds, and a chest. The Iron, Gold, and Diamond cases are crafted by surrounding a Basic Loot Case with four ingots or diamonds of the matching material.
