Regeneration

Regeneration is the ability of a creature to slowly restore health over time without the need of potions, spells or a rest. Characters with a constitution of twenty and higher will regenerate automatically one HP per x seconds, where x decreases with increasing constitution. Potions, items and spells may apply a regeneration effect/bonus.

The games use three differently named status effects to show that a character is regenerating, depending on how they gained the ability:
 * Regenerate
 * Regenerating
 * Regeneration