The Backpack is a Survival Item that serves to expand the character's inventory. It requires 4 Cut Grass, 4 Twigs to craft and Science Machine to prototype. The Backpack itself cannot be placed in inventory or Chest and only one may be equipped at a time.

When a Backpack is created it automatically equips itself in the Chest Slot if it is available. Wearing the Backpack provides 8 additional inventory slots. This item uses the same equipment slot as Armor and Vests, which means wearing one requires sacrificing the benefits of the other.

Although Backpacks cannot be placed in inventory or in Chests, they can be placed on the ground and used for storage. Any item clicked on a Backpack which is on the ground will give the 'Store' option allowing the pack to be filled without equipping it.