Tier 1: Levels 10 through 18
Once you get to level 10, you'll get your first talent point. You'll get another point at level 11, and then every second level after that up to level 81. You'll get talent points at each level after that, to 85. It's an odd schedule.
The first few talents you'll wind up taking are relative no-brainers. At levels 10, 11, and 13, you'll be investing talent points in Darkness, a talent that gives you 1 percent spell haste per talent point. It's a raw damage per second upgrade, obviously, especially now that Shadow Word: Pain is affected by haste. At levels 15 and 17, put your talent points in Improved Shadow Word: Pain.
Will you use Shadow Word: Pain in your rotations? If you're building your shadow priest from scratch -- that is, leveling without the benefit of enchanted heirloom items -- you'll find yourself using Shadow Word: Pain a lot. It's less of a player for those with heirlooms, but any time you get saddled with having to fight more than one enemy, you'll wind up breaking it out. In any case, a stronger SW:P is far more useful at this point than the save-it-for-later talent Veiled Shadows.
Tier 2: Levels 19 through 28
Throughout the leveling process, you'll notice a pattern -- if you're not gaining a talent point, you're being told to revisit your trainer to learn a new ability. In the early going, new shadow spells are few and far between; you're still assembling a basic priest toolkit, and an awful lot of those tools are heal-oriented.
Mind Blast is the ultimate shadow priest spell, and since it's one of the few spells you'll actually be able to cast at this point in the game, you want it to be off of cooldown as much as possible. That's why I recommend you invest your talent points at levels 19, 21, and 23 in Improved Mind Blast.
Improved Devouring Plague is a great talent, but you don't learn Devouring Plague until level 28. Hold off on that talent for now, and instead use your level 25 and 27 talent points in Twisted Faith. Obviously, the 2 percent buff to shadow damage it gives you is welcome, but the spirit-to-hit conversion aspect is exceptionally useful while leveling. Consider this: You're routinely sent to face off against mobs that are often two or three levels above you; your chance to hit against those beasties is miserable. And even if you're facing enemies that are your level, you're still only 96 percent likely to hit them. Hit is always going to be your most valuable stat, so these talent points are no-brainers.
Look at that -- 10 points in, and your talent tree is well on its way.
Tier 3: Levels 29 through 38
Your level 29 talent point is probably the easiest choice you'll ever make -- Shadowform. Everything is more awesome in Shadowform. Taking rides on gryphons is more awesome in Shadowform. Running around the auction house is more awesome in Shadowform. Heck, Shadowform is so awesome that Dawn Moore confided in me that she writes every Sunday Spiritual Guidance column while AFKing in Shadowform. (If Fox says it, it must be true.)
But I digress. If Shadowform were the easy call here, investing the next four talent points to open up tier 4 is going to be somewhat harder. Harnessed Shadows is a terrific talent, but keep in mind that Shadow Orbs don't really pick up steam until you can actually train Mastery at level 80. Phantasm is a pretty useful talent for PvP with far fewer uses in PvE.
So where do those points go? Well, since we can finally cast Devouring Plague now, levels 31 and 33 seem like a perfect time to jump back up a tier and go 2/2 in Improved Devouring Plague. As for levels 35 and 37, I'm going to recommend you take the not-so-sexy Improved Psychic Scream. While Psychic Scream is mostly used in PvP (and otherwise not generally recommended for use in PvE), the new-for-patch-4.0.1 Glyph of Psychic Scream (at level 50, anyway -- use the Glyph of Spirit Tap at level 25) gives Psychic Scream some much-needed PvE cred.
Tier 4: Levels 39 through 48
Tier 4 starts off with another easy choice: Take Vampiric Embrace at level 39. Even with recent nerfs to the ability, its healing is still a godsend for the leveling shadow priest. At levels 41 and 43, I recommend you take the follow-on ability Masochism, which allows you to resore mana when you take significant hits of damage -- obviously useful while leveling.
Also useful while leveling: Shadow Word: Death. It's an exceptionally powerful instant-cast attack, provided you land it when your target is below 25 percent health. Your talent points at levels 45 and 47 are best spent powering that ability up with Mind Melt.
Tier 5: Levels 49 through 58
The most important talent in the fifth tier is the Vampiric Touch damage over time spell; take it as soon as you hit level 49. At levels 51 and 53, I recommend Paralysis. If your target gets paralyzed, it's as good as dead before it'll ever reach you. That comes in exceptionally handy while soloing. And while you're taking talents in tier 5, you may as well finish it out by going 2/2 in Pain and Suffering at levels 55 and 57 -- it turns SW:P into a spell with an effectively unlimited duration and reduces the penalty for your Shadow Word: Death miscasts.
Tier 6: Levels 59 through 68
I will readily admit a standing love affair with my own Shadowy Apparition. It's a genuinely fun talent that actually improves your DPS -- a rarity in Cataclysm talent trees. I recommend putting your level 59, 61, and 63 points there.
Sadly, at level 65, you're faced with a decision between buffing your Shadowfiend -- which you don't get until level 66 -- and taking Psychic Horror, a primarily PvP talent. If you're playing on a PvP server, the choice is easy. Otherwise, you'll be better off taking the tier 4 ability Silence (for the ability to interrupt spellcasting, natch) or the tier 1 ability Veiled Shadows. The latter talent is pretty useless without having access to a shadowfiend, but at least it's theoretically useful in PvE.
At level 65, I chose to take Silence. For my "level 67 build," I took my first point in Veiled Shadows.
Tier 7 and beyond: Levels 69 through 80
Dispersion is our capstone, level 69, 31-point talent. Our talent tree was designed around it. You have to take it -- which isn't necessarily a bad thing. Any kind of mana regen talen is going to come in quite handy while leveling a caster, especially in the modern day, fast-paced world of random 5-man groups.
Once you spend that 31st point, you're allowed to start dipping into the disc and holy trees if you'd like. And that's exactly what I'd recommend you do at this point -- the Twin Disciplines talent in the discipline tree, which provides a 6 percent raw damage increase with a three-talent-point investment, is just too good to pass up. Put your talent points there at levels 71, 73, and 75.
The next few levels give us a chance to fine tune our talent tree and pick up some stuff that we've skipped. At level 77, I like taking that second point worth of Veiled Shadows on tier 1. At level 79, I'd grab your first point in Sin and Punishment. It's something of a temporary pick, because once we get to level 80 -- even though it's now just a short pit stop on the way to level 85 -- I'm going to recommend that you visit a class trainer and have your talent tree reset.
Level 80: The great talent tree reset
Today, I am officially retiring my old level 80 raid-ready talent tree. It's served us well these last few months, but simply put, Wrath raiding is old news. Level 80 is now nothing but the starting point of a new adventure. And a new adventure calls for a new talent tree that reflects our new playstyle and goals.
Over the past few segments, if you've followed me point by point and looked at the result, you'll notice that we've created quite the Frankenstein. It's a damn good build for someone at level 79, but once you're at level 80, it gets immediately outdated. We need something much more ... elegant. (Hold on, let me get my martini glass again.)
And so, with the most elegant of fanfare -- I'm thinking a drumroll from a tuxedo-wearing dude, who is also holding a martini glass with pinky outstretched -- I present the level 80 talent tree!
There's a bit of reshuffling going on. Most notably, we've taken points out of Improved Mind Blast and moved them into Harnessed Shadows. We got rid of Silence for now (it'll be back) and put a couple extra points in the first discipline tier to set us up for level 81. It looks quite similar to our old raid-ready level 80 tree, but there's a notable difference -- this one has Paralysis. Not that great a talent in level 80 raids, but a phenomenal talent while leveling as a level 80 in Mount Hyjal and beyond.
The Cataclysm grind: Levels 81 through 84
Well, here we are. It's time to start talking those Cataclysm levels because, well ... this is the last Spiritual Guidance column I'll be able to write before the new expansion comes out. I know, I'm getting all misty-eyed and emotional too, but we must press on.
That second tier of the discipline tree is filled with two tremendous goodies: Evangelism and Archangel. The two talents work as a team to boost your damage and provide you with a little bit of extra mana regen. At level 81, take your first point in Evangelism; at level 82, take your second point. As shadow priests, this will manifest itself in game as the shadow-specific Dark Evangelism, providing a nice semi-permanent buff to your damage over time spells.
If you're fully invested (2/2) in Evangelism, you can take the talent Archangel at level 83. For shadow priests, this manifests as Dark Archangel, complete with a spectacular looking pair of shadowy wings. You're instantly rebated a significant portion of your mana bar (don't underestimate how important this gets as you near level 85) and your non-DoT spells get buffed by as much as 20 percent over 15 seconds.
The talent point you get at level 84 is far less valuable than the first three you'll get -- there's no perfect place to put it. We've already gotten as much mileage as we can out of the discipline tree, so our answer lies once again with the shadows. I put that level 84 talent point back into Improved Mind Blast (tier 2) knowing that when I get to level 85, I'm going to wipe that talent tree yet one more time.
The final level 85 build(s)
Once you get to level 85 (if Cataclysm comes out next Tuesday, you should be at 85 by Wednesday morning, right?), the game once again changes from a leveling experience to one of grinding heroics and, eventually, raiding. Based on my experience in the Cataclysm beta, I've learned a few things about our talent tree. I learned that Paralysis is great for the solo grind, but it's largely useless in groups (it's not a stun). I also learned that in a 5-man heroic, the Silence ability comes in way too handy to leave off a heroic-grinding build.
That combined knowledge led to the development of this, my recommended level 85 build for a shadow priest destined for days of grinding heroics. There's some room to play around with it a bit, but it's a good place to start. When you're ready to move beyond heroics and start running raids, you'll probably want to remove the points associated with Silence and re-invest in the (arguably) more useful Inner Sanctum. Putting two points there may sound silly to some shadow priests, but world firsts are built on "silly" little damage reduction mechanics like that.
Are you more interested in watching health bars go down than watching them bounce back up? Think it's neat to dissolve into a ball of pure shadow every few minutes? Hunger for the tangy flesh of gnomes? The darker, shadowy side of Spiritual Guidance has you covered (occasionally through the use of puppets).