Entropy Shards are rare materials used in various crafting recipes for advanced items.
They may also be converted into an Arcana Essence by filling a 3×3 section in a workbench. Warning: This action cannot be reversed once crafted, and can only be crafted one at a time. A list of available Arcana armor, tools, and weapons can be found here.
The only method of obtaining Entropy Shards is by voting, where there is a 1/12 chance of obtaining one (8.3%), or by Consecutive Rewards on Day 13, and then every two weeks subsequently. During events, there are sometimes alternative methods of obtaining them. Due to their rarity, they are often sold at a high price.