Magma Golems also have the Knockback skill. It is important to provide backup for the fighters attacking the Golem to prevent them from being knocked backward.
A Magma Golem's regular physical attack is strong enough to kill a level 14 Wizard (81 hit points) in a single blow if that Wizard is not wearing Medium Protection Rings. Any character with Armor Rating under 50 can expect to take 80+ damage from its attack.
Characters with Resisting Magic of 10+ will sustain less than 25hp of damage from the Magma Pulse (without active Magic Reflection). Plate classes can expect damage of 40-70hp from the Magma Pulse (without active Magic Reflection).
Standard battle strategy for fighting Magma Golems is for one cleric in the party to always keep enough mana available to immediately cast Mass Heal in response to the Magma Pulse. Failure to do so will usually result in the death of the currently-targeted plate with the next physical attack.