Mosshide Troll Belt

Magical, flowering vines have been fashioned around the remains of a troll's hide, preserving a fragment of its renowned regeneration ability. While wearing this belt, your Constitution score increases by 2, to a maximum of 20. In addition, the belt's restorative magic activates when it senses danger. While in combat, you regain 1d4 + 1 hit points at the start of your turn if you have less than half your hit points left. This property ceases to function for 1 hour if you take acid or fire damage, or until the next dawn if you drop to 0 hit points.