Here are some important rules:

1. You can borrow one inventory item per day.
   • Note: You and your friends cannot borrow Diamonds, Keys, or Cash from each other.
2. You can borrow inventory from the same friend once per three days.
3. Borrowing does not deduct a use of the borrowed item from your friend's or your own inventory.
4. Borrowing does not limit you or your friend's ability to use the same item at the same time.