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 insides 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 take longer to get wet than your main inventory. 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 Piggyback is a type of Backpack which requires 4 Pig Skins, 6 Silk, and 2 Ropes to craft and an Alchemy Engine to prototype. It is a larger Backpack which has 12 inventory slots but reduces walking speed by 20% while equipped. It has 4 more slots than a Backpack, but 2 fewer slots than the Krampus Sack. It cannot be placed in the inventory or in Chests.
As of the Reign of Giants update, "A Feet of Strength", the Piggyback and its contents are waterproof and will not cause sanity drain while equipped. The Piggyback does not give the player any rain resistance, and using it in conjunction with an Umbrella will not protect the rest of the player's items from wetness. The movement speed penalty was also reduced from -20% to -10% in this update. Used with the Walking Cane, the penalty is negated and the player's speed increased to 115%.
The Krampus Sack is a wearable storage item, like the Backpack. It is an extremely rare drop from Krampus, with only a 1% chance to drop. It has 14 inventory slots, 6 more than a Backpack and 2 more than a Piggyback. It cannot be placed in the player's inventory or in Chests, and it can't be lit on fire.
Even though the importance of only two extra slots may be minimal, the Krampus Sack doesn't slow the player down like the Piggyback does, making it a much better alternative. However, with a lowly 1% drop rate and a significant time investment to spawn a Krampus, it should be said that during any given game it's possible that the player might spend more time trying to get the item than would be saved by not walking slower with the Piggyback. It may be better to ultimately treat the Krampus Sack as an unexpected bonus and/or something to only strive for in one's spare time.
The quickest way to spawn Krampus is by killing a Glommer, so players should take advantage of every full moon cycle to retrieve the Glommer Flower and kill the Glommer in an area where any spawned Krampus will quickly die. Passive mobs will be aggressive towards Krampus, so a Pig or Bunnyman village would be an ideal location to kill a Glommer. Tooth Traps work as well, but Krampus might steal the traps instead of setting them off.
Insulated Pack Edit
Main article: Insulated Pack
The Insulated Pack is a backpack from the Reign of Giants DLC used to expand the character's inventory. While it has only 6 inventory slots, it slows the spoilage of perishable items contained within. It requires 1 Thick Fur, 3 Gears, and 3 Electrical Doodads to craft and an Alchemy Engine to prototype.
Despite slowing the spoilage of food items, the Insulated Pack does not completely work the same way as an Ice Box. Unlike the Box, the Pack will not stop the spoilage of Ice and Ice Cubes and will not be able to freeze a Thermal Stone.
Thatch Pack Edit
The Thatch Pack is a backpack from the Shipwrecked DLC used to expand the character's inventory. It has only 4 inventory slots, however it does not need to be prototyped and can be crafted from the start. It requires 4 Palm Leaves to craft. Thatch Packs are flammable.
Booty Bag Edit
Main article: Booty Bag
The Booty Bag is a backpack from the Shipwrecked DLC used to expand the player's inventory. In addition to having the appearance of a chest of loot, it drops a Dubloon up to once per day, which falls from it into the environment. It can be found randomly floating in the Ocean and is a reward from defeating the Quacken.
Chef Pouch Edit
Main article: Chef Pouch
The Chef Pouch, also known as the Spice Pack, is a character-specific backpack from the Shipwrecked DLC that Warly begins the game with. Warly can craft multiple Chef Pouches with 1 Rope and 1 Cloth. It functions as a slightly larger version of the Insulated Pack, allowing Warly to keep food from spoiling longer from the beginning of the game, and makes an effective Backpack replacement.
Sea Sack Edit
Main article: Sea Sack
The Sea Sack is a backpack introduced in the Shipwrecked DLC, used to expand the character's inventory. While it has only 6 inventory slots, it slows the Spoilage of perishable items contained within. It requires 5 Seaweeds, 2 Vines, and 1 Shark Gills to craft and an Alchemy Engine to prototype. Sea Sacks function identically to Insulated Packs from Reign of Giants.
- The Backpack was added in the The Birds and the Bees & Dogs That Want to Kill You update.
- The Piggyback was added in the Doorway to Adventure update.
- The Krampus Sack was added in the Naughty and Nice update. Before the Underground update, the Krampus Sack didn't appear as an icon on the map.
- The Chef Pouch was added in the Eye of the Tiger Shark update to Shipwrecked. When the player begins the game as Warly, the Chef Pouch is actually dropped nearby, implying that it is supposed to go into the player's Inventory, but fails, as backpacks can not be held in the Inventory.
- When Krampus wears the Krampus Sack, there are no chains surrounding the Sack, while the item obtained from killing Krampus has two chains draped across it. When worn, a faint jingling sound from the chains can be heard while the player is moving.
- The Piggyback's name is a pun, on both the fact it is a backpack made from a pig's skin and on the action of giving a piggyback.
- When Webber examines a backpack, he says that it is like a second abdomen that he can store stuff in. Most likely implying that Webber's inventory is actually the spider's abdomen.
- A backpack can be burned and extinguished to be able to keep it in one's inventory. Relogging will reset this.