Audience

I've used this strategy to level a warlock in almost best-in-slot T6, and a warlock who didn't even have BoA gear for the first two levels and was in TBC greens.

Guide

Introduction

I put together a video to illustrate what is definitely my favorite way to level in Wrath:

http://warcraftmovies.com/movieview.php?id=89547

While TBC leveling was strong with a healer, just casting instant-cast dots and using siphon life, along with instant Howl of Terror, Wrath of the Lich King gives us some very very nice tools as locks to level.

Talent Points

When you hit 71, this is the spec you want: Warlock: 21/41/0

(note: Glyphs have changed since I leveled, I'm not actually sure which is better, the felguard glyph or CoA.)

You're building towards this level 80 spec: Warlock: 30/41/0

One of the nice things about this spec is that each talent point after 71 actually increases your dps -- not something warlocks are used to in their trees, which are so focused around a handful of "heavy lifting" talents and tons of filler or situational talents.

Mechanics/Spell Changes

A couple key things happened that make this work appallingly well:

Level 71

Obviously. You couldn't pick up both felguard and siphon life before.

Fel Synergy

Heals your pet for 15% of the damage you deal.

Basically, it keeps your pet at full health while he's mitigating 5% of the damage done to you and tanking a mob or two along the way.

Fel Armor change

Well, it used to be 30% in-combat mana regen from spirit. Nice for raiding, but actually terrible for leveling.

The good news is that while its current version (+2% of your health every 5 seconds) is bad for raiding, it's great for leveling and provides another trickle-heal.

Spell pushback changes

Before you couldn't get a howl of terror off with 5 mobs beating on you. Now you can, because spell pushback is capped at two interrupts, with a max of one second pushback. Hello Howl of Terror! Now you actually can use your AE Fear without having to talent it.

This means an AE-dotting spec that isn't deep affliction is actually doable.

Spell casting and spell channeling pushback has been changed to the following:

• When casting a spell:
  • The first and second hit will add .5 secs each to the cast time.
  • All hits after the second will have no effect.
• When channeling a spell:
  • The first and second hit reduces current duration by 25% of total duration each.
  • All hits after the second will have no effect

Gear

Two piece T6 definitely helps: the healing from corruption ticks lets you postpone bandaging for a bit longer.

The BT exalted warlock ashtongue trinket is actually useful as well: Ashtongue Talisman of Shadows (thanks to Nihilithak on Ner'zhul for that reminder!)

Outside of that, while more +dmg and haste is good, you don't have to be geared to the teeth -- just pull what you can handle and when (not if!) you die, laugh as you run back from the GY, knowing that an awful lot of mobs killed you.

Crit gear isn't useful. Spirit would be (scaling lifetap, and +dmg from the spirit), so don't be afraid to swap out some of your current pieces for dmg/spirit gear as you level up, particularly if it means you're shedding "useless" crit.

Elites

You can solo almost every group quest in Wrath. Just use your voidwalker instead of felguard if you need to and healthfunnel. Throw dots up as you have gcd's available (make sure you use siphon life to offset the health loss from health funnel), use shadow bolt if it's an easy quest.

Use soulshatter if you're out-aggroing your pet.

Tips

I found some useful tips as I was leveling:

Don't pull one when you can pull four

Killing a single mob is slow for you. Only need one other mob for a quest but there's five around him? Just kill them all, you'll appreciate it later.

Don't eat/drink; don't stand and bandage

Stop before you're at 10% health and mana. I took breaks around 50% or so, sent my pet off to hit something I had dotted, lifetapped down, and then bandaged back to full health/mana and kept moving.

Watch your distance

Pet poofing/mob leashing is very much a risk here. Don't send your pet at a mob on the edge of your pull: send him somewhere in the middle and pull the edge mobs to the middle.

Lifetap early

One mistake I made at the start was waiting until I got low to lifetap. Why? I have no idea, I never do that in raids or groups...

Dot, dot, dot, (lifetap), dot, dot, dot (lifetap) is a great way to start out. That maximizes the trickle healing you're getting from siphon life and Fel Armor.

Why not full Affliction?

You just don't gain enough, in my opinion, to go deep affliction versus 41 demo.

You can't use the new dots you get, they all have cast times (UA/Haunt). You don't need instant howl of terror anymore. Eradication is of minimal usefulness here, and can only proc once every 30 seconds. Death's embrace doesn't apply, nor does everlasting affliction.

Pandemic is good, yes, but as you level to 80 your crit rate will be cut in half -- so it becomes less valuable as you level (although it will be good once you get into raid gear again and get raid buffs, of course.)

About the only thing you're missing is being able to pick up Shadow Mastery -- +10% dot damage. It's nice, but you can start building points into that starting at 72/73.

Compare that to getting 10% more health (I don't die tons when I do this, but the health is nice since Fel Armor works on a percentage basis), having a pet tank (nice for medding up, nice for keeping one mob off you, nice for group quests), and shedding 5% of the damage done to you via soul link.

Plus, the demo tree gives you more raw +dmg -- affliction just doesn't boost your existing dots (past the points we already have in there) that much other than SM. Demo brings demonic aegis and demonic knowledge, both of which go some ways to making up for not getting SM as early.

Where this won't work

If your server is too crowded at WotLK launch, you might end up very frustrated. You definitely need a fair number of mobs to pull this off, as it's weak on single-target dps (killing four is only a bit slower than killing one, not just because four is fast: it's also because one is slow.)

If you just can't ever get enough mobs to make it worthwhile, respec to demo/destro and just level that way.