You can always store an unchained item in the inventory to open up some space on your game board, and you take it back to your board whenever you want.

If you want to put an item in your inventory, please drag your item onto the inventory bag. (Please do not open your inventory bag to put an item into it.)

Once you need your item again, click on the inventory bag to open it and tap on the item you want to place on your board.

Inventory comes with limited space, but you can use your gold to open up new slots and increase the capacity permanently.