The Charm of Life is an item added by Twilight Forest and comes in two ranks. They are heart-shaped items, but should not be confused with Hearts from Legend Gear.
When the player would take damage that would kill them, a Charm of Life will activate from the inventory, if one exists, to prevent the damage and healing the player. The charm will be consumed in the process.
The first rank will heal the player back to 8 health () and bestow a weak Regeneration effect for 10 seconds. The second rank will restore all health and activate several effects, including a more powerful regeneration and protection for 30 seconds.
You can combine 4 level I charms to produce a level II charm in the crafting grid.