The Backpack is a Survival Item that serves to expand the character's inventory. It requires 4 Cut Grass and 4 Twigs to craft and a Science Machine to prototype. The Backpack itself cannot be placed in the inventory or in Chests 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. Unlike other items that go into the Chest slot, Backpacks do not have durability.
Although Backpacks cannot be placed in the inventory or in Chests, they can be dropped on the ground and used for storage. Any item hovered over a Backpack while it's on the ground will give the 'Store' option, allowing the pack to be filled without equipping it.
In the Reign of Giants DLC, the Backpack is a flammable item. When set on fire, everything inside won't be affected by fire but the Backpack will eventually burn to Ashes, dropping anything it had inside. Care should be taken when dropping a backpack near a campfire to prevent it from burning. The backpack is not waterproof, but items in the backpack will stay completely dry. If the player does not have full water protection, it is recommended to keep one's fuel and food items in a backpack during the rain.
- The Backpack was added in the The Birds and the Bees & Dogs That Want to Kill You update.
- A backpack can be burned and extinguished to be able to keep it in one's inventory. Relogging will reset this.
- Sometimes the player can't pick up a backpack in the Caves if it is dropped due to the player's death.