Amulet of Vitality Storing

This amulet stores extra vitality to then be used at a time when greatly needed. When you start a long rest, you can store 1 hit dice into the amulet. The maximum hit dice the amulet can store is equal to your level. If you have multiple types of hit dice, it must be of one you have remaining. It keeps the types of dice you have stored. As a bonus action, you can use some or all of the dice stored up to restore your HP by the hit dice stored in the amulet.

When you first attune to this amulet it is empty, and it loses all of its charges if you are no longer attuned to it.

Notes: Healing