Clothies after all - Like priests and mages, warlocks wear their pajamas into combat. Unfortunately their lack of armor is mitigated by large health pools and various self-healing abilities, making them a hardy, if not the hardiest, clothie class. However, they still crumble easily against melee DPS. As you work on higher priority targets like healers, DO NOT let a Warlock run amok. An unchecked Warlock is extremely disruptive and damaging, so keep him or her occupied with crowd control, a melee toon (preferably Warrior or Rogue) or even a pet.
Warlocks need time - Most of their DoTs are instant, so you can fully expect a full set to be slapped on you as soon as they get into range. However DoTs need time to do their dirty jobs and will not kill you outright. They CAN be healed through or dispelled. Dispellers need to recognize the tell-tale purple haze of Unstable Affliction, or risk being silenced and suffering the feedback damage, which can crit.
The Warlock's deadliest nukes mostly require a cast time. Like other casters, silence, counterspell and interrupt effects are deadly to them. Get up close and personal, and most casters will have problems getting a spell off. This is especially true for warlocks as they have only two instant 'escape' abilities, both fear-based: Death Coil which has a 2-minute cooldown, and Howl of Terror (heavy Affliction locks only) with a cooldown of 40 seconds. Force warlocks to blow these abilities under conditions favorable to you and you'd gain control of the battle.
Full blown Fear has a cast time of 1.5 seconds, making it hard to cast under melee duress. Most warlocks will instinctively reach for death coil if they can't get fear out.
Another good way to counter these nukes is using line-of-sight to your advantage. Ducking behind pillars and jumping off the bridge (in Circle of Blood, everyone's least favorite Arena) when you spot a casting animation from the warlock are all viable ways of breaking LoS.
Unlike their affliction and demonology brethren, heavy destruction locks come with a larger arsenal of instant nukes and can deliver burst damage as quickly as mages, or quicker. This chart shows some tell-tale characteristics of the different flavors of warlocks and what to expect from them generally:
Affliction and demonology warlocks are most common in the Arenas currently.
Durability - warlocks come loaded with Health, some have more than warriors. Coupled with a range of drain abilities and Soul Link, they can take a beating - especially with healers on their backs. In Arenas, you generally want to down healers and/or 'softer' targets first. This puts warlocks somewhere in the upper middle in terms of kill priority. This bears repeating here: even if you're not focusing on downing the lock, DO NOT let him or her run wild!
Fire-and-forget DoTs - quick-fingered warlocks can DoT up your entire team if you let them go unmolested. These nasty things will eat away at your team without further button-mashing from the warlock players and will stick around even after you kill the warlocks!
Pets - another source of disruption and control. Not as damaging as warlocks themselves but bothersome nonetheless - deal with them with a quick snare or stun effect if they are making your life difficult, especially felguards. Note that felhunters are highly resistant to all forms of magic, so don't waste time casting stuff on it. The felhunter is generally the pet of choice for many warlocks due to its powerful anti-caster abilities: Spell Lock and Devour Magic.
Fear and control - you'll want as many ways to break fear as possible - from trinkets to abilities. Some players use both PvP trinkets, at the expense of bonuses. Part of the Warlock's disruptive power in PvP comes from the ability to CC multiple targets at the same time: fear, banish (for other warlock pets) and seduction.
Warrior - You'll simply have the most anti-fear tools. Stick to the Warlock, swing and Pummel away. Ignore their pets, unless it's a succubus, which you can easily fear away. Put up Spell Reflection to bounce some nastiness back at them.
Rogue - Stay close and swing away. Deal damage as quickly as possible and save your PvP trinket for death coil or howl of terror. Put on Cloak of Shadows in the unlikely event of the fight swinging out of your favor.
Hunter - Seek your pet on warlocks, this will serve the triple purpose of dealing damage, interrupting their long-cast spells, AND forcing them to possibly blow their 'escape' abilities on your pet. Maintain your distance by using a combination of traps and wing clip. Feign death to make their big spells fizzle. Snake traps are also handy.
Mage - Counterspell is your friend. Catch warlocks in their casting animation, and you effectively shut down half or more of their arsenal for eight seconds - an eternity in the Arenas. Blink behind them to break LoS. Use Ice Block to wipe out all DoTs, including Unstable Affliction (with no ill effects), to break their rhythm.
Priest - If you're shadow, Silence is your best friend. Constantly Dispel away the DoTs, watching out for Unstable Affliction. Try to catch both Warlock and pet in your fear. Buff yourself with ALL available buffs, so that felhunters might devour some 'useless' ones. Don't forget Fear Ward.
Shaman - The strat here again is to disrupt a warlock's casting as much as possible. Earth Shock whenever you see the casting animation. Drop grounding and tremor totems to help with the fear situation.
Druid - As a feral druid, go right up in cat form and scratch their eyes out. You also want to minimize being in caster form as much as possible. Cyclone and Entangling Roots are handy to put warlock pets out of action for a bit. Keep yourself HoT'ed up and constantly remove their curses.
Paladin - Put up your Shadow Resistance Aura, and try to stall warlocks till your teammates can come to your aid if you're Holy. If you are Retribution, warlocks will kite you. Use Blessing of Freedom to counter Curse of Exhaustion, and Repentance/Hammer of Justice to pin warlocks in place while you run up to them with Pursuit of Justice. Seal of Justice helps to keep them in place while you swing.
Warlock - A mirror match! Banish the pets (except felhunters who'll probably resist) and wail away on their masters. Curse of Tongues makes their nukes even harder to cast, but remember that they can do to you whatever you can do to them. Stay mobile, use LoS to your advantage. A well-timed Spell Lock from your felhunter can be invaluable.
There you have it, a basic guide on dealing with warlocks. Do you have any other class-specific tips on bringing them down? Share!
Here are the numbers for the first week of Arena Season 3:
Comparing this with last week's numbers:
We now have marginally more hunters in the smaller brackets, but it's really too early to discern any trend. Priests are showing a nice even distribution across all three brackets in the first week, while other classes pretty much maintain similar standings. This could mean that top players are simply falling back on established combos to secure early leads.