Poison is a recurring status ailment in the Star Ocean series. Characters afflicted with this ailment turn green and have green bubbles floating above their head. When afflicted, they lose small amounts of HP every few seconds when in battle. In First Departure, Second Evolution, and The Last Hope, when in the field, they lose HP while walking, denoted by the screen flashing green.
The ailment can be cured with spells like Antidote or Condition Cure; with items like Antidotes, Aquaberries and Medicine Bottles; or staying at an inn. Armor and accessories like Amulets of Antivenin can prevent this ailment when equipped.