This is a compendium of information on serious PvE (raiding and challenge modes) as a Balance Druid. It contains everything a beginner needs to achieve basic competence at DPS, as well more detailed discussion for people more interested in understanding the theory or more advanced play. The article is supplemented by the attached spreadsheet.
Anyone posting on the thread should have a good familiarity with the current state of Moonkin theory, either from this guide or from anywhere else. At the very least, do not ask questions that are directly answered in the guide; they will be infracted. It's good to be familiar with things that have been discussed on the thread as well, we start new thread each patch so they don't get too long. In particular, know what's been discussed on the last few pages before posting.
In addition, I tend to discuss any Druid research/theorycraft work I do on Twitter:
Jay (HamletEJ) on Twitter
And I upload videos of myself playing various boss encounters here (currently on hiatus from raiding, but hoping to put challenge mode-related content there in MoP):
Arawethion's Channel
Many of my older theorycraft posts are on this blog and still useful:
http://elitistjerks.com/blogs/1152-hamlet/
I don't use it much anymore–unsure where I'll put any new theorycraft stuff I do (other than this thread); twitter is your best bet for keeping up with my WoW work.
Talents are very different from what they used to be before MoP. For the most part they provide utility-type benefits whose value is dependent on a particular situation. As such, there's no general-purpose correct set of talents, and very often choice of correct talents will depend on your understanding of a particular encounter. I expect much of the discussion on the thread will be about talent choice for specific purposes. For now, some general comments on each tier:
The talent list, for reference.
For reference, the following former talents are now available to all Balance Druids, some with slight variations in functionality: Nature's Grace, Balance of Power, Euphoria, Moonkin Form, Shooting Stars, Sunfire, Solar Beam, Owlkin Frenzy, Starfall, Lunar Shower.
One miscellaneous point of mechanics that people should understand: DoT's read their spellpower and haste values, and any %damage buffs, at the moment they are cast. These do not update while the DoT is ticking. Crit chance and target debuffs, however, do update dynamically.
Very slim pickings here. No Major Glyphs affect our DPS, except that [Glyph of the Moonbeast] is necessary if you want to use Dream of Cenarius for DPS. [Glyph of Rebirth] is useful in any raid situation, but not as critical now that the default Rebirth has been increased to 60% HP. Otherwise, use any Glyph that provides meaningful utility at a given fight (but this is mostly limited to [Glyph of Hurricane] and [Glyph of Solar Beam]).
None of these add any DPS, so it's entirely up to personal taste.
Glyph of Grace is the only one that affects game mechanics, and could be of occasional benefit.
Horde: Troll is best for DPS, since it gives Berserking and Beast Slaying. Tauren gives no DPS benefit.
Alliance: Worgen is best for DPS, since it gives 1% crit (Darkflight is also a nice perk). Night Elf gives no DPS benefit.
To be clear on how Symbiosis works, when you cast it on a target:
Spells the Balance Druid can gain are:
Here is a handy chart of all spells the target gains.
The only one that adds DPS is Mirror Image. However, it is a small DPS benefit, and some of the survivability options are quite strong (in particular Cloak of Shadows, Anti-Magic Shell, and Unending Resolve). I'll supplement this section if I come up with anything more specific to say.
In roughly descending order of importance.
Intellect:
Intellect provides 1 spellpower and 0.00039% to crit per point. With Mark of the Wild, Heart of the Wild, and Astral Leather Specialization, it provides 1.169 spellpower and 0.00046% crit (2168 points per 1% crit, about 3.5 times weaker than 1 crit rating).
Spellpower:
Intellect, without the talent bonuses or crit bonus. Basically a weaker form of Intellect that only appears on weapons and trinkets, but is still good.
Hit/Spirit/Expertise:
340 hit/expertise rating gives 1% to hit with spells, up to the cap of 5100 rating against a level 93 target (4080 against level 92). 1 Spirit and 1 hit/expertise rating are identical for gear selection purposes (if you ever play Resto at all you probably want to gem Spirit). You always want to cap out hit if you can do so without sacrificing Int. Remember that hit rating over the cap does nothing, so you need to reforge hit to other stats if you gear has more than this amount (see below).
Haste rating:
425 haste rating gives 1% spell haste. Haste adds extra DoT ticks at certain points. Assuming the haste benefits of Moonkin Form and Nature's Grace, breakpoints occur at 5273, 10289, and 15318 (see WrathCalcs for more). With the 4-piece T14 bonus, they are instead at 3706, 8089, and 12517. When you're close enough to a breakpoint to reach it, sacrifice other secondary stats to do so (even a small amount of hit is acceptable).
Critical strike rating:
600 crit rating gives 1% to crit. With a Burning or Revitalizing meta, crits do 2.06 times the damage of non-crits. Crit is currently spreadsheeting as our strongest secondary stat when haste breakpoints don't come into play.
Mastery rating:
320 mastery rating adds 1% to our Eclipse bonus, added to the 30% we have to start with. Generally our weakest secondary stat by a small margin.
The stat priority at the moment can be summarized as:
Int >> haste (to breakpoint) ~> hit (to cap)* > crit = excess hit (reforged to crit)** > half Int (gems) > haste > mastery
(for a really basic version, ignore haste breakpoints and slight gains from Spirit reforging, and use:
Int >> hit (to cap) > haste > crit > half Int > mastery).
*Being below hit cap isn't great since misses can mess with your Eclipse timing. But if you're very close to a haste breakpoint, I'd give up a little hit if necessary and make it up when you get your next upgrade.
**The “real” per-point value of hit rating is largely irrelevant, as you always gear/reforge so as to remain hit capped. Therefore the effective value of hit/Spirit/expertise on gear is equal to whatever stat you reforge in/out of to account for the excess hit. Since in practice you'll usually keep haste at a breakpoint, excess hit will go into or out of the crit bucket.
Since gems are changed in MoP to have half as much Int as other stats, all colors of gems are nearly equal in value. As a result, always match colors in each socket. A far as the “second half” of each gem, it looks like secondary stats slightly outperform Int at half value. Since you're likely reforging to hit cap and/or a haste breakpoint, use whichever secondary makes things more convenient.
So for example, if you were fine on your caps and just want straight crit, you would gem:
These slots are tricky. See the note above about the value of excess hit. For basic use, use whichever makes it more convenient to stay at hit cap, the Int or the hit/spirit/expertise version. Advanced players should choose based on whether the excess hit can actually be cashed into crit rating through reforging.
Both of our tier 14 (Regalia of the Eternal Blossom) set bonuses are in the expected range, roughly 2% DPS (the 4-piece is somewhat stronger if you use Dream of Cenarius). Use them when you have access to them.
Most trinkets can be evaluated based on their stats just like any other item, if you use the uptime on their proc/use to compute an average stat value. WrathCalcs can also help you evaluate trinkets.
(fill T14 trinkets once there is further analysis)
Typically the best time to activate is with your DoT's. Not only does this ensure you get a set of buffed DoT's, but you often refresh DoT's at the beginning of Eclipse. Even better, if it's a 20 second buff (like many are), your 14-16 second DoT's should get a second set of refreshes during the trinket activation. So, macroing trinkets to a DoT is not a bad plan if you don't want to deal with them manually all the time.
Here's a macro you can stick into any spell (such as Moonfire) to activate a trinket without spamming error messages or sounds:

/script UIErrorsFrame:UnregisterEvent("UI_ERROR_MESSAGE");
/console Sound_EnableSFX 0
/use 14
/console Sound_EnableSFX 1
/script UIErrorsFrame:RegisterEvent("UI_ERROR_MESSAGE");
/use Moonfire
(14 is the bottom trinket slot, 13 is the top. Make sure to put these lines before the spell cast in your macro.)
Use [Recipe: Flask of the Warm Sun] and [Recipe: Mogu Fish Stew] or similar Int buffs if you don't have access to those.
The best DPS potion is [Recipe: Potion of the Jade Serpent]. You want to use it during Bloodlust. When you're trying to completely maximize your DPS, remember you can click a potion just before combat starts (ask your tank to count down), and then be able to use another potion later in the fight.
Excluding profession bonuses.
Non-gathering professions are all very similar in value, giving a bonus with a benefit of roughly 320 Int. If you're picking fresh professions right now, it looks like Engineering, Blacksmithing, and Leatherworking slightly edge out the others, and Jewelcrafting is slightly weaker. However, I wouldn't switch around existing professions until this is all verified a bit more.
Blacksmithing: An extra socket each in your wrists and gloves, each with a [Design: Brilliant Primordial Ruby], gives 320 Intellect. However since another gem (such as [Design: Smooth Sun's Radiance]) might be even better, Blacksmithing can give slightly more benefit.
Engineering: Synapse Springs give 1920 Int, for 10 seconds out of every 60, for 320 Int on average (varies slightly in practice). Has potential to slightly outdo other professions since you can time the use to be most efficient.
A macro similar to the one given above for trinkets can be used for glove tinkers–the glove slot is number 10.
Leatherworking: 500 Int to bracers in place of the usual 170 Int gives you 330 Intellect.
Alchemy: Mixology (with your [Recipe: Flask of the Warm Sun]) will give you 320 Intellect.
Enchanting: 160 Int to each ring gives 320 Intellect.
Inscription: 520 Int/100 crit to shoulders in place of the unusual is a gain of 320 Intellect.
Tailoring: Lightweave Embroidery gives 2000 Int for 15 seconds, 20% proc on damage, 60 second cooldown. The average benefit with perfect procs is around 500 Int, minus the 180 Int you usually have on your cloak, for an increase of around 320 Int. This is slightly reduced due to delay on the proc, but increased since you get a proc at the very beginning of the fight, so the end result is similar to other professions, but with a little variance.
Jewelcrafting: 2 [Design: Brilliant Serpent's Eye] in place of 2 [Design: Brilliant Primordial Ruby] gives 320 Intellect. However, since [Design: Brilliant Primordial Ruby] is probably not your best gem (see above), the gain is slightly less. In addition, Jewelcrafting may grow weaker when epic gems are introduced.
Gathering professions are weaker:
Herbalism now gives a haste cooldown via Lifeblood. At 2880 haste for 20s every 2 minutes, it averages out to 480 haste.
Skinning gives 480 crit rating.
Mining provides 480 stamina, but no DPS gain.
I'm not going to set out full BIS lists here, for a few different reasons. It's best for you to read this guide until you understand the class well enough to choose gear based on the things I've said above. But here's some overall advice to help provide some guidance.
Caster epics have Intellect, Stamina, spellpower in the case of weapons, and 2 out of the 5 secondary stats: crit rating, hit rating, haste rating, mastery rating or Spirit. Keep in mind a few rules of thumb, which are enough to get a quick estimate of the value of any piece:
Since the 5% Intellect from Leather Specialization is a strong bonus, you should generally ignore cloth gear.
To compare items more precisely and check for upgrades, use WrathCalcs to test different setups. You can also use WrathCalcs to compute DPS weights for all your stats for guidance. Generally though, the above rules are sufficient to figure out which of two items is better. See below for more on WrathCalcs.
Here is my best description of the thought process behind fine-tuning of secondary stats.
1) The ultimate goals are to a) be at hit cap, b) be at the highest haste breakpoint you can reach, c) maximize crit while maintaining a and b.
2) With that in mind, your first goal is to look at current gear, say after swapping in a new upgrade, and decide whether hit and haste (respectively) need to go up or down from there.
3) If, generally speaking, they have to go up, pull points from mastery into either hit or haste on any mastery item. If you still need more, pull from crit on any crit item.
4) If they have to go down, reforge either haste or hit into crit on any item that doesn't have it.
5) Once that's done, if you still need more haste or hit, use gems to get what you need. Otherwise, use crit gems as described above.
[I want to turn the below into a separate stand-alone guide, since a whole section on reforging algorithms isn't really specific to Moonkin and is kind of unwieldy. I'll leave the old language here for now since I don't know when I'll get around to that. This guide will still have all the Moonkin-specific info above.
Given all of the options we have for shuffling stats around now, it can be confusing to find the optimal way to select gear and gem/reforge it while remaining at the hit cap. Computational optimizers like Rawr can assist with this, but knowing the basic guidelines can save you a lot of time when going over your options. It's best to mock up your setup in WrathCalcs and decide how you want to gem/reforge, and then actually do it all at once on live servers.
This is a basic way to approach reforging that covers most situations:
1) In each slot, put on your best individual item (see above), ignoring the hit cap. This will generally be your highest-ilvl leather spellpower item, preferring crit items and set bonuses where possible.
2) Gem in the way described above.
If you are under the hit cap of 5100, do the following until you hit 5100 (or 4080 for level 92 targets):
3A) On any crit/haste or crit/mastery pieces, reforge the haste or mastery to hit or Spirit (you may prefer Spirit so you can use your items for Resto spec as well).
4A) Reforge any other pieces. Remember that you can reforge hit onto an item with Spirit, and vice versa.
If you were over the hit cap, do the following until you're just over it:
3B) Reforging hit/Spirit to crit on any non-crit items.
4B) Reforging hit/Spirit to haste on any crit items.
5) Once you are at hit cap, if you have any unreforged items that don't have crit, reforge the haste or mastery on them to crit.
6) There's some possible further optimization by reforging haste/mastery to hit on some items and reforging back on others, or checking for haste breakpoints, or by changing between gems, but at this point you'll have to work it our yourself or resort to automated tools.]
The first rule of DPS is to always be casting (or waiting out a GCD after an instant). Anytime a spell ends, you should already have queued your next one (see below). Don't delay a cast to make a decision or react to proc–train yourself to start another spell regardless of what's going on, and change the subsequent spellcast if necessary after you've had another second to think.
As a preliminary note, this type of macro might be useful for automatically assisting with your nukes when you have a raid member targeted:

#showtooltip /use [@target, harm, nodead][@targettarget, harm, nodead][] Starfire
First, there is an in-game option to decide whether keypresses activate on press or on release. Choose what you like and keep it in mind for learning your timing.
When you send a spell command to the server, if your character is unable to cast immediately (typically because it's still casting or GCD-locked from your last spell), the server will see if you become ready to cast within a certain short window. If you do, it will begin the cast immediately. You can set the length of this window with an interface option called “Custom Latency Tolerance.” You want to set this value to a high enough amount that you can always press the next spell key comfortably before the current spell finishes, and never have a gap between casts. But you don't want to set it too high, because you can't change your mind after you queue a spell, so your reaction time is effectively slower if you “lock in” each spell a long time before it begins casting. Experiment and find something you're comfortable with.
For more detail, continue to the following sections.
You will generally operate in a four-step cycle.
Basically, you cast Wrath until Lunar procs and cast Starfire until Solar procs. But once DoTs and other instants are involved, thinking in terms of the four-phase cycle helps you plan your casts well.
Note that unlike in the past, Starfire is somewhat stronger than Wrath, meaning you do more DPS in the Lunar half of the cycle.
Unlike in Cataclysm, if you cast an instant immediately after the nuke that triggers Eclipse, the instant will be affected by Eclipse.
Solar: You want to watch for when your Solar energy is at 60 or higher, so that you know your current Starfire cast is your last one, and queue a Sunfire or other Solar spell.
Lunar: Wrath now, like Starfire, gives its energy on cast completion. If your Lunar energy as you start a Wrath is 70 or higher, queue Starfall for your next spell (even if it looks like it's on cooldown), followed by Moonfire or other Lunar spell.
Do your best to avoid casting extra spells beyond what's necessary to proc Eclipse.
If you use the mod Balance Power Tracker (below) things look slightly different. That mod can display a modified energy bar, which projects your energy value from currently casting spells, so all you have to do is check for when it reads 100. Remember that if you move or interrupt a cast though (or if your spell misses), your energy will appear to go back down.
We now have the ability Astral Communion to set our energy to whatever value we like (multiples of 25) in advance of an encounter. As you attempt a particular fight more and more, you can sometimes plan out your Eclipses for certain AoE/movement phases. I'm not going to give a boss-by-boss guide here, but you should pay attention to the order of events in each fight and refine your routine. An important point is that you always delay an Eclipse by spamming Moonfire with Lunar Shower or casting the off-Eclipse nuke, so sometimes you can use that to control when you enter or leave Eclipse at various points in an encounter. At some encounters, planning out your Eclipses at specific points in the fight will be a major part of doing good DPS. Most commonly, when a fight has AoE phase, you will want to do whatever is necessary to make sure you're in Solar when that phase begins, by delaying Eclipses as necessary.
Typically you will start an encounter by going to 75 energy towards Lunar (this requires 3 casts of Astral Communion if starting from neutral, since it goes towards Solar first), so you can start Lunar with one Wrath at the beginning of the encounter (more detail in Advanced Techniques).
By and large, you want to use this whenever it's available. There is one major exception: do not cast Starsurge twice within the same Solar Eclipse. This will cause you to be at 0 energy (instead of 5 energy) after 6 total spells, ending Solar one cast early. If you do not have Soul of the Forest, then it's fine (in fact, it's good) to cast a second Starsurge at 5 energy, as the final spell of Solar, if you have it available.
A more minor exception is that if you are close to a new Eclipse, saving Starsurge for Eclipse can be slightly better, as long as this does not increase the number of casts to reach Eclipse. If you're unsure, using Starsurge whenever it's up (subject to the above exception) is fine.
DoT's are similarly strong as they were in Cataclysm. You want to do your best to maintain very high uptime on both of them (Sunfire has replaced Insect Swarm, but no change conceptually). Typically, the only time you will hold up recasting of a DoT is if it falls off and the corresponding Eclipse is coming up very soon and/or you don't have Nature's Grace–you'll wait one or two casts and refresh at the beginning of Eclipse. If both DoT's are coming up at around the same time when you start Eclipse, cast the on-Eclipse DoT first.
In practice, the duration of a DoT (around 14 or 16 seconds) is similar to the time it takes to get from one Eclipse to the next, so it's easy to work in a pattern where you recast both DoTs at the beginning of each Eclipse. There's some talk of clipping the Eclipse DoT just before the end of each Eclipse instead, I'll update after looking into that more.
Remember that Cataclysm changed the way DoT refreshing works–when you refresh a currently ticking DoT, you no longer waste a partial tick. Significantly, if you refresh a DoT when it has only one tick remaining, there is no loss at all.
DoT ticks use your spellpower, haste, and +% damage (e.g. Eclipse) values from the moment the DoT was cast–they do not update in real time until the next time you cast the DoT. Crit chance of the ticks, on the other hand, does change dynamically if you gain or lose crit buffs while the DoT is ticking. Because the entire DoT is effected by your stats at the moment of cast, there can be detailed decisionmaking in when to apply them–see “Advanced Points” below for more.

/use Force of Nature /petattack
This way, while your Treants are out, you can just press your FoN button again to make them attack your current target.
These have a small portion of the guide, but don't be deceived–good use of them tends to be the hallmark of top players. But no advice I can give here is a substitute for awareness and familiarity with your class.

#showtooltip /use [nocombat] Revive /stopmacro [nocombat] /use Rebirth /ra Rebirth on %t
Nothing significant will change during the rotation, except that DoT's are exceedingly good. Make sure to DoT any possible target as soon as Bloodlust starts, probably even clipping any existing DoT's at that point (use any timers here if possible, such as Berserking and your Potion, and especially Celestial Alignment). If you have a Nature's Grace near the beginning of Bloodlust, even better to spam DoT's with.
The basic solution to any movement situation is to try to get the most out of DoT's and Lunar Shower. Cast Moonfire/Sunfire the instant movement begins (or even just before) to start stacking the buff, then spam it on the target while running. Use Wild Mushroom, and any other instants you have available (such as Shooting Stars) as well. Planting Wild Mushrooms at the enemy's feet while moving take some practice but is worthwhile; remember that you can wait until your next Solar Eclipse to detonate them. Finally, if at all possible, you want to be in an Eclipse for movement, although you might often have little control over this.
It's important to manage our DoTs well during high-movement situations. You want to plan your casting so that you cast DoTs (or other instants) while moving, and nukes while standing still. This requires you to be highly aware of both your spell rotation and your surroundings, so you can anticipate movement. It's always worth delaying a DoT by a few seconds to cast it while moving, so you can cast another nuke while still. This also holds true for other instants.
In multi-target (3 or more) situations, use a mix of Wild Mushroom, Hurricane, and DoTs.
On encounters with a major AoE component, a big part of your planning should revolve around being in Solar Eclipse at the right time.
The Balance spec has a number of interacting buffs and procs, making it currently one of the complex classes in the game to play well. There's no concise list of rules for what to cast and when (which is part of why this guide is so long); you need to have the solid understanding of how the different abilities works and use your judgment in a variety of situations. When you feel you've mastered the basic techniques described so far, here are more subtle points you can try to start working into your play:
There is only one addon I use that is specific to Balance spec:
Balance Power Tracker: An alternative energy bar. Among various display features, this bar has the option to add the expected energy from currently casting/spells to your energy bar, to help you see when you need to swap spells for the next Eclipse. Try this feature out to see if you like it, but remember that if you've been practicing with the default energy bar, the timing change will take a bit of getting used to.
WrathCalcs (attached to this post). Moonkin theorycraft spreadsheet. Will give you the exact value of stats/talents/glyphs in your current setup, and lets you experiment with different rotations. Originally made by Adoriele here. I've since taken it over and used it as the platform for my own theorycrafting, reflected in the version posted here.
For those of you who used WrathCalcs in Cataclysm, things are the same. There's a front page where you can select gear, gems, enchants, and reforges from drop-down menus. Stats are automatically totaled and passed to the second page, where you'll find all the other features: talent and buff selection, and detailed outputs.
For everyone else, here's a basic description to get you started:
1) Input your gear, gems, enchants, and reforges on the front page. The basic rule is that any light-blue box is a dropdown menu where you can choose something. The sheet will automatically black out any enchant/gem slots that don't exist, and will highlight any inactive socket bonuses or meta gems in red. To un-reforge (or un-gem or un-enchant) and item, just the delete the current reforge/gem/enchant selection.
2) On the second page, input your talents, glyphs and buffs. Again, light blue boxes are menus where you can enter your setup. Don't modify the pink boxes, which are the stats inherited from the front page–these are shown so you can see the stat weights (see below). You can also set some parameters about how you use your spells in the purple boxes.
3) Basic results are in green boxes. You can read your overall DPS in the “main results” box (also copied to the front page so you can easily see how it changes when you change gear). Other green boxes show your hit/haste breakpoints, the DPET of each of your spells, and the damage breakdown of all your spells.
4) Advanced results are in the blue boxes. These require the use of data tables, which you have to recompute manually by pressing F9. These include:
a) next to each stat, buff, glyph, and talent, the amount of DPS and MP5 derived from that particular thing. For stats, it shows the benefit of having 1 more of that stat. For talents and other bonuses, it shows the value you currently gain from that bonus (i.e. the amount you would lose by dropping it).
b) next to the spell table, the amount by an additional stat point improves each individual spell.
More at [Balance] Mists of Pandaria 5.0, Guide and Discussion
More Reading