The intention of the Healer role is pretty simple: heal everyone.
Usually the priority of healing will be something like this:
Also watching who has aggro by keeping an eye on the party view is important. If one person has all the aggro then don't bother spending 3 seconds casting greater heal on someone else.
Line of Sight
To be able to heal your party you need to be in line of sight. If you aren't in line of sight your spell will fail. Since it can be tricky to keep the entire party in line of sight, you can ask them to do a few things that will help.
- Stay Together A party that bunches up is a party thats easier to heal. Note that this strategy isn't always the way to go, especially if you are fighting mobs that have dangerous AOE abilities.
- Fight Smart Have the tank and DPS draw the targets into an open, flat position. This allows the priest to stand basically where ever they want to. If fighting on star ways its important to fight just at the top so the priest can get line of sight from below or above, where ever is safer.
- Don't Chase Don't chase runners from the group unless you've been given that specific task within your group. Running off around corners out of line of sight will cancel any spells in progress. If a greater heal is just about to go off and you run out of LOS you waste all that casting time which might be the difference.
Mana Conservation
Aggro Management
Debuff/Buff Management
Watching your party members health is not the only thing a Priest must do. A priest must also be quick on the Dispel Magic in case your tank becomes incapacitated. Its not uncommon to see all melee classes in a group be stunned or polymorphed and the entire combat move towards the casters. If they make it over before you can dispel the tank you are looking at a wipe. In this case the priority is always to dispel the tank as they will be able to control the aggro and draw the mobs away from the casters.
Other
Other tasks a healer can do:
- Patrol Watch As a priest you wont be in the thick of things. You will be standing back staying out of the way, perhaps hiding around a corner and healing every so often. During this time you can be scanning the area for approaching patrols or runners that have broken off from the main combat.