Backpack
The Backpack is a special storage item that allow player to carry food, drink, medicine, ingredients (and any other item we can think of later). Works only when attached, and all data is stored in the server, not in the backpack.
The player has only one backpack, that is created when the account is created.
Also backpacks has levels, that determines how much the player can carry. Leveling up your backpack means spending L$ with a NPC vendor in the game's HQ land, and can be done only level by level (you can't pay directly to level up a level 1 backpack to level 5. You need to buy all intermediary levels).
When you create your account, a record for the backpack, filled with Food and Drinks, will be created. You then go to the TESS-GEN Main Store and get one of the free Backpack Starter Skins (only the invisible is available for now). Since you can have only one backpack, skins are just makeup for the backpack, but yiu need to have at least one to be able wot use the backpack.
More skins will be available in the game later, in special occasions like Holidays, or a craftable item with a special recipe. But remember, skins are just make-up, they don't add another backpack, nor increase the carrying capacity.
[TODO: table with levels, price, and carrying capacities]