Although there are many variations of clerics throughout the world of video games, their primary purpose comes down to one thing: healing. In MMOs, clerics are typically one of the most sought after classes because without a cleric, a group is often completely inefficient. In some games, clerics are at least competent in melee combat but not anywhere near as skilled as a warrior or paladin.
Clerics are the masters of healing and resurrection. Clerics also wield some of the best health and armor buffs in Norrath. They also have the ability to not only cure poison and disease effects, but also protect friends from these status effects with a line of resist buffs. Clerics do have the ability to wear plate armor but do not usually have the ability to solo well. Although, they do excel in combat against undead. The resurrection line of spells cast by Clerics allows them to not only bring back fallen friends, but also restore the experience lost in the death. Clerics can also get themselves out of certain death with the most powerful shield buff in the game, Divine Aura, which renders them invincible for a short time but without the ability to cast or attack.