Understanding what holy and discipline can do
There are two healing specializations available to priests, discipline and holy. Historically holy has been thought of as an AoE healing spec, and discipline as a single target or tank healing spec. While not entirely untrue in the past, these ideas are no longer accurate in the present game. Personally, I like to think of holy as an all-purpose healing spec (like all-purpose flour, only priests shouldn't be made into pancakes) while discipline is more of a specialized healing spec.
For holy this means the spec can be used for almost anything. Holy priests are equipped to deal with all sorts of damage, making them solid tank healers and extremely formidable raid healers. Chakras (stances which holy priests can swap between to improve certain spells) allow holy priests to easily switch from one role to another in mid fight.
Discipline priests, on the other hand, are strong against a few specific things and weak against others. Whether the damage is raid wide or single target doesn't matter -- discipline priests can handle both equally well these days -- it's how and when the damage occurs that matters. Discipline priests are best at dealing with predictable damage, while they have more difficulty responding to damage that targets players at random. To remain viable a disc priest must know the script of each encounter and tailor his spell usage to it. A good disc priest is like the mortar holding together the bricks; he'll fill in the rough edges and weaknesses to make the healing team solid.
Holy single target healing
You single target heal whenever you heal a tank, or spot heal (meaning to individually heal random members of the raid). When doing this as a holy priest, you ideally want to be in the Chakra: Serenity stance. This stance improves your single target spells by a flat percentage and also causes them to refresh the duration of Renew on your target. Below is a guide on what spells you'll use most, and when to use them.
Holy AoE healing
- Holy Word: Serenity You'll only be able to use this spell while in Chakra: Serenity stance (it replaces Holy Word: Chastise on your ability bar). This spell has a short cooldown, but is strong and cost effective; it's your best spell when it comes to single target healing. You want to use this as much as you can to conserve mana, though sometimes it's useful to save for an extra second if you're expecting your target to take a succession of big hits.
- Flash Heal This is your emergency heal when Holy Word: Serenity is on cooldown. Use it if you think your target may die in the next second or two without a heal. Use it sparingly outside of emergencies, as it's not cost efficient.
- Greater Heal After Holy Word: Serenity, this is your go to spell for healing damage. It's a slow heal so it won't save anyone in a hurry, but if you can spare an extra second you'll make big dents in a target's depleted health bar using this. If you need to use this spell a lot, alternate between casting it and Flash Heal. Flash Heal triggers Serendipity and will reduce the cast time of your next Greater Heal (or Prayer of Healing).
- Prayer of Mending This spell reacts to damage automatically, so you can (and should) apply it whenever you can and let it do its thing. The best strategy is to fire it off to the tank and repeat whenever the spell isn't on cooldown. Most priests start with this before they've even entered combat.
- Renew Think of this spell as a buffer. Apply it to a target and it will feed additional healing to him while you're casting other spells. This spell can buy you extra seconds when you're multitasking between targets, or keep a target hanging on when they're receiving constant, heavy damage.
- Heal Single target healing sometimes means waiting a second or two for enough damage to accumulate on a target to make them worth healing with Greater Heal or Holy Word: Serenity. If you don't like doing nothing in those extra seconds, you can cast this spell instead. It does a small amount of healing for a small amount of mana. Most priests don't bother using this spell.
You'll AoE heal whenever it's more efficient to heal multiple targets as a group, rather than individually. For this, you'll want to switch to Chakra: Sanctuary
stance. This stance improves your AoE healing by a flat percentage and reduces the cooldown of your bread and butter spell, Circle of Healing.
Discipline single target healing
- Circle of Healing As I said, this is a bread and butter spell for holy priests. When you need to heal multiple targets this is the first spell you go to, and the first spell you check to see if it's off cooldown. It's a smart heal, meaning the lowest health players in range of your target will be prioritized. This spell is very cost effective, so use it as often as you can if there is a need.
- Prayer of Healing When you need more healing, and Circle of Healing is on cooldown, Prayer of Healing is sometimes the spell you want. I say sometimes because it heals based on party. In a 5-man dungeon this means you heal everyone in your party, in a raid it means you only heal the people in group 2, group 5, or whatever group your target is in when you cast the spell. Because of the way this spell works, it's not always going to be the answer to the damage you're looking at, but it sometimes is. It's especially useful when the entire raid gets hit by an AoE attack ... Just pick a group and cast away.
- Renew This spell works as more of a filler when you're AoE healing. If Circle of Healing is still on cooldown, and the damage in your raid is too spread out to effectively use Prayer of Healing, Renew is the way to address small damage on multiple targets. (If there are individual targets who have taken a lot of damage, an occasional Flash Heal doesn't hurt.)
- Level 90 talent (Cascade, Divine Star, Halo) Which talent you use will depend on how much damage your group is taking, how often they're taking it, and where they're positioned. Halo is ideal for larger groups (such as 25-man raids) since it affects the most targets, but it requires more space to use effectively (see this article for more information on using Halo). Divine Star works well for large and small groups, as long as they're condensed to one area. Cascade works for small and large groups when players are spread out.
- Holy Word: Sanctuary Like Holy Word: Serenity, this spell replaces Holy Word: Chastise when you're in Chakra: Sanctuary stance. This spell provides a steady stream of healing in a location on the ground you specify. Once placed, it will heal any targets standing in that location, so it's best to use it when you know your targets aren't going to be relocating soon. The spell is very expensive though, so try to make sure you're going to get the most out of it. That means positioning it under large clusters of people (not just a small pack of two or three) and using it when you know other players will be taking damage.
- Lightspring or Lightwell Lightspring operates on almost the exact same usage guidelines as Holy Word: Sanctuary. Make sure to use it when players are damaged enough for the spell to work (if your group isn't below 50% health, the Lightspring will just sit there and look pretty). Also be sure to place it in a location where your party is going to be for the duration of the spell so no charges go to waste. For information on using Lightwell, the principles in this old guide still apply.
- Prayer of Mending Use this spell as you would when single target healing.
Just like with holy, you'll single target heal as disc whenever you're tank healing or healing random targets in your party or raid. That said, you'll probably find yourself single target healing more as discipline, even when several targets have been damaged, just because this spec doesn't have as much AoE capability.
Discipline AoE healing
- Penance Similar to Holy Word: Serenity for holy priests, this is your best single target spell (strong, efficient, short cooldown). Try to use it as much as you can, and remember that if you glyph it you can use it while running.
- Power Word: Shield This is the spell discipline priests are infamous for. Place it on a target and they'll be protected from a set amount of damage for 15 seconds. What makes shields strong is that you don't have to heal reactively with them, you can place them preemptively and negate the damage before it ever touches your target. So while this means you don't need to have lightning fast reflexes to respond to damage, you do need to know when damage is coming so you can place a shield before your target is attacked. (Placing a shield after a target has taken damage is as waste if they don't take any more damage before the shield expires!) This spell is very expensive and if in excess it can drain you.
- Flash Heal, Greater Heal, and Prayer of Mending Discipline priests use these spells like holy. To save space, please consult the sections above.
- Renew When cast by a discipline priest, Renew isn't quite as strong, though it does fill the same role. When you can't keep a target alive with all you've got, and you have as second to spare, use Renew to boost your HPS.
- Heal or Smite Heal is pretty much the same for disc as it is for holy, but there is an alternative option to casting Heal when you've got nothing to do: Smite. Because of Atonement, Smite (and Holy Fire) will heal members of your party or raid whenever you deal damage to an enemy target. You can't control who your target will be, but Atonement automatically targets the lowest health player in range.
- Spirit Shell When single target healing, Spirit Shell should be used much in the way that Power Word: Shield already is. When you know a large amount of damage is incoming, use Spirit Shell and cast away on your target. Greater Heal is the most efficient way to stack up the absorption on your Spirit Shell, but you can use Flash Heal if you're in a hurry. (Please see this article for information on how to use Spirit Shell.)
As I already mentioned, disc priests don't have the same AoE strengths as holy priests, so you won't be doing as much AoE healing by default.
- Prayer of Healing Similarly to holy priests, disc priests will only want to use Prayer of Healing when it's efficient to do so. (Unfortunately, we don't have as many options to use before Prayer of Healing!) Stick to using this when there is raid wide damage, or enough damage in one group or party to justify it. One thing to know is that using Prayer of Healing as a disc priest will apply a small shield (Divine Aegis) to the targets it hits, making it a great heal for pulsing damage that you might have to heal for.
- Prayer of Mending and Level 90 talent You may also consult the AoE holy section for these spells.
- Spirit Shell Have you ever heard of bubble spam? It was a popular style of healing that disc priests used in previous expansions. This spell makes it so you don't have to bubble spam. Instead, you can cast Spirit Shell then cast Prayer of Healing on as many groups as you can. This will apply several, powerful shields at once, instead of having to individually apply shields as disc priests used to. As with all absorptive healing, you want to use this preemptively. A shield does no good after the damage is done.
- Power Word: Shield Of course, if you want to bubble spam you still can. Blanketing your raid or party with shields will provide much stronger shields than Spirit Shell can, though it's much more costly to do it this way. Be careful with this playstyle, it's easy to go overboard.
Spiritual Guidance is WoW Insider's source for priest information. For information on playing the class, check out our Mists of Pandaria guides for discipline, holy, and shadow. For getting geared up, check out our pre-raid gear guide.