TBC Shadow Destro [Guide]
Since there strangely seems to be a lack of class guides for 2.4.3 content, I thought I would make this one for warlocks. Specifically, it's for destruction warlocks.
Why destruction?
Simply put, destruction offers arguably the best damage in the game. At low gear levels affliction is very nice, and there's something to be said for having a token affliction lock just for the raid utility they offer. Demonology is more for PVP or leveling, and less viable in a PVE setting. Destruction locks have no rotation to speak of so it's almost impossible to mess up and they are pretty durable for a caster. The biggest downside to playing destruction is that it can be really boring if you go shadow. Fire is also viable at low levels, but in my testing it always seems to fall just a bit behind shadow. I'll focus therefore on shadow, and how to min max it.
Your spec
Your spec is this.
You have a bit of wiggle room here. For example improved healthstone, improved voidwalker, and aftermath. If you want to really min/max, see what rank of improved healthstone the other warlocks in your raid have and pick whatever they don't have, so that you can have three different ranks of healthstone in a raid. The choice between aftermath and pyroclasm is up to you. You rarely use rain of fire, so I prefer aftermath, but they're both filler points. The trick to this build is the combination of demonic sacrifice and shadowbolt. By sacrificing your succubus you gain 15% shadow damage, and since you just spam shadowbolt that's a straight 15% increase to your damage done with a single talent point. This along with the talents in your destruction tree make shadowbolt hit extremely hard. This spec is pretty strong initially, and just gets better with gear as shadow and flame makes the spellpower coefficient very high.
How to play it
It's incredibly easy. Summon and sacrifice your succubus. Keep fel armor up. Then, make sure you apply your designated curse, generally curse of the elements, but if another warlock is using that you can use curse of doom. After that, it's all about getting as many shadowbolts into the fight as you can.
There are tricks to this. The best advice I have is to focus on economy of movement. If you want to maximize your throughput you should try to position yourself so that you have to move as little as possible. When you do move, make sure you are making use of that break in damage. Maybe you life tap and then throw out a deathcoil, reapply a curse, use shadow ward, whatever. I would also recommend using multiple buttons for shadowbolt so that you can spam it as fast as possible. I use both my mouse wheel up and down as well as 4 on my keyboard. Lastly, try to stack and time your cooldowns as smartly as you can and use them as often as you can. Orcs have a great racial bonus to spell power, and if you have on use trinkets make sure you use them as well. Potions, drums, etc will all help you min/max your damage output.
When it comes to AOE, your best friend is seed of corruption. It does massive amounts of damage on AOE pulls when you don't have to single target. The best way to do this is to cast seed, tab target to the next mob and cast another and just keep doing that. If you cast seed on the same target and that target doesn't take enough damage you might end up overwriting your own spell and not do any damage at all. Once the first seed goes off, it will trigger the other rest that you have put out and you'll have a large chain-reaction and see your DPS skyrocket.
However, I will offer some words of caution. If you just lay in with seed you might pull aggro and die. Give your tank a moment to establish threat. Rain of fire is mediocre by comparison, but I will occasionally use simply because I know I will pull aggro and die if I use seed.
Itemization
Your first objective is to get 202 spell hit. This will reduce your chance to miss a shadowbolt as much as possible. Spellpower is your next most important stat. The more you have the better, remember that your shadowbolt scales insanely well with spell power. Because of ruin your spell crits do double damage instead of 50% more damage, so spell crit is also huge. You really can't have too much. Spell haste is something you don't really see much of until you get into the later raids, but once you are into t6 content it is also a great stat to pad. Stamina and intellect are lesser considerations, you need enough to survive and encounter, but you don't need to stack it unless you are doing fight-specific tanking (such as on Illidan or Leotheras). That content is a bit outside the scope of this guide.
Spell penetration is for PVP, so you can basically ignore that when it comes to PVE content.
Professions
First of all, you tailoring should your #1 priority until you get access to t6 level gear. The frozen shadoweave set is BIS until the end of t5 and beginning of t6. It offers a massive amount of shadow damage. The downside to this gear is that it lacks other stats, such as spell hit and crit. Another set you should strive for is the spellstrike set. This set also offers massive amounts of spellpower as well as spell hit and crit, but lacks stamina and intellect.
After tailoring, any crafting profession that benefits your character is good to have. The goggles from engineering are fantastic and better even that the spellstrike hood. Enchanting gives you ring enchants, jewelcrafting gives you epic gems before they become available with t6 content. Leatherworking gives you drums, which are basically like a mini-bloodlust/heroism that you can use for your party every minute or so. Once you get to Sunwell, the final raid of the expansion, most guilds require all dps to go LW for the drums. If you want to be really hardcore, you can give the bonuses of multiple professions simultaneously. For example, you could level enchanting, enchant your rings, then drop it and pick up jewelcrafting and get your epic gems, then drop it and pick up leatherworking for drums. Unlike in WotLK, you do not need to maintain these professions to obtain the benefit they offer once leveled up, only tailoring requires that you be a shadoweave tailor in order to have the FSW set and engineering at 350 to wear the goggles.
Crafting professions are not really helpful at all, aside from making you some extra gold. I would recommend leveling an alt to farm mats for you, and save more useful professions for your main.
Add-ons
Omen
This is must have for anyone that wants to play PVE. In Wrath and subsequent expansions, threat was built into the default user interface, so you could get by without an add-on to track it (though the add-on does a much better job of it). In vanilla wow and TBC, that functionality doesn't exist, so the only way to know if you're going to pull aggro is with a threat meter. With this spec, your threat is extremely high, so you have to really pay attention.
Some type of buff/debuff tracking addon
There are numerous add-ons that can accomplish this, so pick whichever suits you best. You need to know what duration is left on your curses, demonic sacrifice, etc.
Enchants
Head - Glyph of Power (The Sha'tar, Revered)
Shoulder - Aldor/Scryer Inscription (faction dependent)
Cloak - Subtlety (300 Enchanting Thrallmar/Honor Hold/AQ40)
Chest - Exceptional Stats (345 Enchanting)
Bracer - Spellpower (360 Enchanting)
Gloves - Spell Strike (if under 202 Spell Hit, 360 Enchanting) or Shadow Power (300 Enchanting)/Major Spellpower (360 Enchanting)
Legs - Runic Spellthread
Feet - Boar's Speed (360 Enchanting)
Ring - Spellpower (360 Enchanting, only works on the enchanter's own ring)
Weapon - Soulfrost (375 Enchanting)
Boar's Speed for boots might not be obvious, but remember that you really want to try to maximize your throughput, and being able to move more quickly means that you can get more shadowbolts into the fight. This is your BIS enchant list. Obviously, some of these slots can be enchanted with less expensive versions of these such as 40 spell power to weapon instead of Soulfrost or Mystic Spellthread instead of Runic Spellthread.
Gems
So let's assume you know next to nothing about how gems work. Some armor has slots for gems that you can put in it which will let you customize it to suit you. Gems come in a variety of types. Meta gems are only for some head armor items and will only fit into a meta gem slot which has a white color to it. Some helms don't have a meta gem slot (such as the spellstrike hood) but have three regular gem slots. Some helms don't have any gem slots at all.
Regular gem slots come in three colors, red, blue, or yellow. You can put any color of non-meta gem into any regular gem slot, but if you want to activate the item's socket bonus you have to match the colors. Yellow sockets can be activated by yellow, green, or orange colored gems. Blue sockets can be activated by blue, purple, or green colored gems. Red sockets can be activated by red, orange, or purple colored gems.
Your meta gem is Chaotic Skyfire Diamond (you'll need 2x Glowing Nightseye to activate it).
If you are below spell hit cap, gem Great Dawnstone in everything else. If you're going for a head slot that doesn't have a meta and you're below hit cap, then don't worry about the Glowing Nightseye. Once you have your spell hit capped, gem for spell damage with Runed Living Ruby. If the socket bonus is good and you want to gem spell crit with a Potent Noble Topaz or spell hit with Veiled Noble Topaz have at it.
Blue slots can be ignored other than when you're trying to activate the meta, as they don't offer much in the way of DPS and the socket bonus will rarely be better than the lost spell power.