thalz.com

All monsters is used to counter both the physical have a defense rating and magical attacks. For exemple, a "Sentinel" is substantially armored compared to other monsters in its level range. It has a better defense against weapon attacks which then makes it hard for most characters near its level to launch a sufficient attack.

On the other hand, Magicians are less adept at killing monsters which employ magic defense including "Luster Pixies", who enjoy lesser vulnerability against magical attacks. Other monsters have elemental strengths and weaknesses that make them, more or less, defenseless against certain elemental attacks. A case in point is the "Fire Boar", who is weak against ice-elemental attacks, yet strong against fire-elemental attacks.