Sanctuary

       Usage: cast 'sanctuary' <target> : cast 36 <target>
      Effect: Halves the damage taken in combat by the target
        Cost: 50
    Duration: 4 hours
Casting Time: 12
      Target: One MOB or character

If you are a new player this is a spell you want to have maintained or given through a piece of equipment.

The classes that get the spell sanctuary are:

cleric     : Level  35 (excellent)
priest     : Level  25 (excellent)
monk       : Level  60 (excellent)
bard       : Level  55 (fair)
druid      : Level  29 (excellent)
paladin    : Level  80 (average)