Some attacks have poison effects. If the attack hits the monster will take normal damage as well as become poisoned, and take one extra damage immediately. Every turn the monster is attacked whether it is a hit or a miss the monster takes one extra damage.
Poison does not stack, a poisoned monsters takes 1 damage when attacked, if an attack with poison successed in hitting them again it will act as a normal attack.
Poisoned monsters will not take poison damage if they are not attacked with the attack command. Using an item, even an attack item, on a poisoned monster means they will not take poison damage. Poisoned monsters will also not take poison damage while benched.
Using items Potion (+20) and Potion (+10) on a poisoned monster will cure the poison, however, they can be poisoned again.
Healing the monster with the healing barcode also cures poison.
If a monster has poison effect it is a good idea to attack with the poison attack for the first round and then use the strongest attack from then on to get maximum damage.