Tuesday, March 18, 2008

Leotheras, Randomness, and Resists

Leotheras the Blind in Serpentshrine Cavern is almost a perfect fight. Leo alternates between human and demon form, staying in each form for about a minute. As a human, he dual-wields and occasionally whirlwinds around the room, spinning towards random people. Leotheras wipes threat after the whirlwind and when he changes form.

In demon form, Leotheras casts an AoE Chaos Blast targeted on the person tanking him. Most guilds use a warlock in Fire Resist gear to tank him in this stage. Leotheras also summons Inner Demons for up to five members in the raid. You are the only person who can kill your Inner Demon, and if you fail to kill your Inner Demon in 30 seconds, you are Mind-Controlled for the rest of the fight.

This fight is--with one huge exception--a great deal of fun. Threat is wiped often, so DPS has a very stop and start aspect to it. It reminds me of the children's game Red Light, Green Light. As well, killing your Inner Demon is a thrill, especially for a healer. It's great fun to wear a bit of DPS gear, and be able to drop everything, and go medieval on some demon.

The big exception is Chaos Blast.

First, a bit of background on resists. There are two types of resists in WoW: partial resists; and binary resists. If a spell is pure damage, it is subject to partial resists. Basically, with partial resists your resistance works like armor, and prevents some of the damage on every cast. If you have 75% resistance (365 Resist) 75% of the damage from each cast is prevented.

However, if a spell has a non-damage component (like a Frostbolt's slowing effect), it is subject to binary resists. Here, resistance works more like Dodge, and you have a chance of either avoiding the attack completely, or taking full damage. If you have 75% resistance (365 Resist) you take no damage 75% of the time, and full damage 25% of the time.

Chaos Blast has a non-damage component, and thus is subject to binary resists. Specifically, each time you are hit with a Chaos Blast, you get a debuff which increases the amount of Fire damage you take.

So what happens is that the warlock takes no damage when she resists a Chaos Blast, but takes full damage when she fails to resist. Therefore damage is very spiky, and the spikes get larger and larger as debuffs accumulate. The big problem is that late in demon phase, if the warlock tank misses two resists in a row, she can take over 15K damage in slightly over 2s.

This is extremely hard to heal, especially as the warlock is taking zero damage 75% of the time. Cast-cancelling heals helps, but it's very common for the warlock to die. Guilds usually soulstone the warlock, and have druids ready to battle res.

By my calculations, during a demon phase there's about a 15% chance the warlock will take a double blast when she has 6 debuffs already on her. That's pretty much a guaranteed dead warlock for guilds at that level of content. That means across the entire fight, there's a 56% chance the warlock will be killed at least once during a demon phase.

This is terrible design for a raid fight. And quite frankly, it ruins what is pretty close to a perfect--and above all, fun--fight. This fight would be so much better if Chaos Blasts used partial resists instead of binary resists. I'm not really sure how the debuff would be applied, but I'm sure that a solution could be found.

In general, binary resists are a bad idea for damage-dealing spells. They make fights way too swingy. It would be much better if the damage component was separate from the debuff component. The damage component should always be handled by partial resists, and extra debuff components can be handled with binary resists (because a partial debuff often doesn't make sense, you either get the debuff or you don't).


  1. If you have 75% resistance (365 Resist) 75% of the damage from each cast is prevented.

    That's not quite how it works for partial resists. You can either resist partially 0%, 25%, 50%, 75% or 100%. On average you'll resist 75% of the damage with 365 resistance against lvl 73 mobs, but it won't be 75% for each and every spell. Still far easier to heal than binary resists, of course.


  2. I couldn't agree more. We've always just had a Paladin DI the Warlock if the debuff gets too high, but that's a pretty lame way to do a fight.

    In fact, I really don't care for bosses that kill people as part of the fight, like Teron or Kazrogal. It's like, no matter how good you are, no matter how good your guild is, it doesn't matter because some of you are going to die and there's nothing you can do about it.

  3. I agree, the binary resists can be very dangerous to a Warlock tank.
    I think Blizzard made the decision to use binary instead of partial resists in this fight on purpose. Partial resists would make the demon form really trivial and boring for healers.
    As a healer, you don't really have any other duty than keeping the tank alive in that stage of the fight (save for the <15% phase and Inner Demons).
    The other "warlock tank" encounters use partial resists, for example the Kael'thas and Illidan fights.
    The difference is, in both of those encounters the raid takes a LOT of damage from other abilities, so it must be possible to keep the warlock alive with 1-2 healers. In the Leotheras encounter, most healers can focus on the warlock.

    What we did when the radius of Chaos Blast was nerfed back in the day - we switched to a Warrior tank in FR Gear. If both the tank and the melee DPS move to max range of the hitbox, there wont be any problem.
    The Warrior tank is much more easy to keep alive, for obvious reasons. (improved Def-Stance, several emergency abilities).
    The only problem will be the reduced TPS of the Warrior tank, if too many resists happened in a row. We used a Paladin who switched to FR Aura at 4 debuff stacks to counter the resist problem.

    Anyway, as there are many Warlocks who like to tank, i guess Blizzard should have made them the better choice for that fight :)

  4. I really liked the Leo fight as well.

    In the end, its a gear check on your lock and healers. Pallys need to have the mana pool and regen to spam big heals. Locks need the stamina and resist.

    What makes a strong raid is people who are geared and speced to reduce the randomness of the fight.

    Another trick my guild used was DI'ing the Lock. It drops the debuffs, the lock removes it immediately and still has all of his buffs. Keep that locks pet alive too.

  5. My raid leader actually calls out "red light/green light" in vent during the whirlwind phases - good fun!

  6. We use a paladin tank for elf form, and bear tank in FR gear (plus pally aura) for demon form.

    The paladin can throw his shield to pick up the boss from wherever he's run to (he also keeps up SoV ticks), and the bear has the HP to eat the damage. (This may also be because we don't have a demonology warlock.)

    We make sure to bring him to 15% during demon phase, and then a soulstoned paladin DIs the druid tank to wipe away the accumulated fire debuffs.

  7. I know what you mean about his randomness. We dug through a lot of WWS trying to understand why the tanking lock went down.

    Narrowed down to these posibilities :
    -Imp went down if it's another lock. Got the tank warlock to keep personal imp up.
    -Nitemare Seeds needed for this fight.
    -Not enough HoTS on her. Then again, it could also be a timing issue since HoTs are based on 3-secs tick.

  8. We haven't run SSC really since 2.4, but since we were having trouble with the FR Warlock being able to make the raid a few times in a row, our Tankadin(Me) switched to the Demon phase, since no one else had bought Fire Resist gear. Our Warrior tank has little to no problem picking the Human phase up so long as the Shaman drop Spitfire Totems for him to focus on before the transition. I tend to have more health and survive better than the Warlock ever did, though I do have a bit of trouble with mana regen, since most of the fight I'm not getting healed from resisting most of the blasts. I generally get grouped with a Shadow Priest for this fight.