Hello and welcome to the 4.2.x Cataclysm raid mechanics thread.

This is the thread for discussing on an encounter by encounter basis what defensive and offensive cooldowns and abilities work and for recommendations around which spec is better for which fights and why. We are interested in knowing that Cloaking can immune from ability X, but we are not interested in how many Ret pala's your 25 man set up includes or how long you spent wiping on Ragnaros HC last night. Those of you who have seen the 4.0.x thread should have a good idea of what is trying to be achieved here.

I will keep this post updated as much as possible and it shouldn't be more than a day or two from something being confirmed as working or not working to it appearing here in this post.


The below is the initial discoveries of posters in this thread. Very little of it could be considered confirmed at this stage, but this should be a good starting point. Thanks to all contributors for their input. If I have misworded or misunderstood (or just missed) anything anyone has said please PM me.

Beth’Tilac
Both Cloak of Shadows and Feint can be used to mitigate Emberflare damage
Deadly brew/crippling poison can slow Spiderlings

Lord Ryolith
Using Blade Flurry on his legs will hit both legs causing him to walk in a straight line
If you have any issues with staying in range during a stomp (say you're at the end of the hit box such that you have more time to avoid Magma Lines), running forwards at the end of a stomp can keep you in range the entire time.
If you're required by your guild to frequently target swap, WP/WP CAN be viable for Combat and Sub. The general rule of thumb is that IP/DP takes roughly 30 seconds to be superior (to WP/WP). Therefore if you end up swapping legs more often than that (improbable but possible), then you should think about using WP/WP.
Feint can be used on concussive stomp
Jumping on Stomp may work - further testing required
Stomp can be Cloaked - both the damage and the knockback.
Alternative strategy to jumping on stomp is to reverse away from him as he casts if timed properly you will remain in range until he casts and then will be just out of range for the stomp and you can resume following him without dropping a swing.
Eruption stacks can be cloaked off.

Alysrazor
Killing Spree - Caution recommended as when using KS on the Blazing Talon Initiates, there have been incidents of players being teleported to Alysrazor even when she should be out of range, further reports indicate that a poorly timed KS can get you one-shotted by her cleave
Glyph of Kick - Can help if on interrupting duty for fireblast from Blazing Talon Initiates (inherent risks of using that glyph notwithstanding)
Feint and Cloak of Shadows both work against Firestorm
Can still parry during burnout
As assassination if you are flying it is recommended to drop backstab from your rotation to avoid energy capping as much and max out dps, rupture is still to be used though.
If you stand on the initiates at the edge you can still attack without being hit by Brushfire
Cloak of Shadows works on the tornados and will not remove your stacks of Blazing Power
When Alysrazor re-ignites, if you have maintained Blazing power, you will want to keep both vanish and tricks on the tank to keep from aggroing
Tricks of the Trade should be used on the Hatchling tank to further enhance their 1000% damage buff.
Burnout: feint works on Blazing buffet and Full power. Try to save the last feint so it will cover full power knockback damage. On heroic it is worth throwing up a recuperate just before the burnout ends for added survivability.
Following a tank death, a hatchling can be evasion tanked and the damage buff should help you down it before evasion expires.

Shannox
Traps can be disarmed, although doing so will stop you dpsing while the trap is disarmed so be careful not to cap energy
Vanish seems currently unable to drop threat on this boss, even being killed and combat ressing does not drop threat, it is not clear if this is intended mechanics or just a bug at this stage.
Cloak can remove the debuff from Immolation Trap, and can prevent it being applied if the timing is correct
Riplimb is slowable as soon as Shannox throws the spear until he returns it to his master he can be slowed by a maximum of 50% and will gradually regain speed back up to 100%


Baleroc
Killing Spree - Can cause problems with spreading torment or placing you closest to the crystals, as always with KS, caution is recommended.


Majordomo Staghelm
Cloak of shadows will not remove searing seeds but can immune the detonation alternatively feinting 5s before the explosion will reduce your damage
Smoke bomb will not prevent Majordomo Staghelm from leaping at a random ranged player during cat phase.
Feint works on Flame Scythe as does Cloak
Burning Orbs is not cloakable
As combat instead of switching to the add in the cat phase if you keep dpsing the boss with blade flurry up you should hit both and maintain all your pesky buffs (this does require you to move between the boss and the add)


Ragnaros
Killing Spree - should be behaving correctly now - unless you try and KS the Magmaw trash, that's bad
Sulfuras smash - both the firewall damage and the debuff can be cloaked
Blade Flurry can still cleave the Sons of Flame while Ragnaros is being targetted.
You can cloak the Blazing Heat debuff on Ragnaros, preventing any fire patches from spawning.
You can Feint Ragnaros' Hand of Ragnaros (the knockback).
You can also Feint Ragnaros' Magma Trap Eruption.
Using Shadowstep on Ragnaros is a bad idea while he is in the lava.
Sons of flame can not be slowed but can be stunned
Cloak and Feint both work on Molten Inferno cloak is able to resist all damage from this while the cloak is active
Smoke bomb does not appear to prevent seeds targeting
Thrown weapon does work against the living meteors
Meteor impact can be cloak-immuned
Molten Inferno adds (Molten Elementals) can be slowed

Blade flurry(any cleave really) on Rhyolith will damage to both feet causing him to walk in a straight line. It is a great tool for guiding him around accurately, but be sure to turn it off when you need him to turn.

Cloak does not remove the stacks you get from standing near the crystal while fighting Baleroc.

Disarming traps in the Shannox encounter helps the raid, but eats into your personal dps and gives you a debuff called Jittery that doesn't allow you to disarm anymore traps for somewhere between 10 and 15 seconds. Sorry, I didn't notice during the fight exactly how long the debuff lasted.

The Damagepenalty Shield is doubled on the second Feet.



Killing Spree on Ragnaros works properly now.

Cloak doesn't remove the Searing Seeds from Majordomo Staghelm either.

You can Cloak both the firewall and the resulting debuff from Ragneros' Sulfuras Smash.

While this is regarding a situation that ideally should never happen, cloak does prevent damage from Wave of Torment (the pulsing AoE that you get when no players are close to crystals).

Also, a warning to combat rogues on Alysrazor: when you're killing the Blazing Talon Initiates, keep an eye out for where Alysra is before you use KSp, since you can easily jump over to her if she's flying by.

I noticed similar strange behavior on Alysrazor with Killing Spree. Occasionally when I used it on an Initiate I would get transported across the room, even when Alysrazor was nowhere near by.

Similarly you have to be careful when you use KSp on Ragnaros. It is safe to use most of the time but you have to watch out for Lava Waves, Sulfuras Smash locations and other similar mechanics.

On Shannox, Vanish does not seem to drop your threat 100% of the time. The only time I got my threat to drop successfully was when I ToT and then vanished. However I do not think this is intended because getting battle rezzed does not drop your threat either, it seems not being able to drop your threat is intentional but it could be a bug.

On Alysrazor, if your the one flying and dpsing I think that Assassination is the better spec to go because you have such a huge amount of haste that the energy regeneration part of Adrenaline Rush kind of goes to waste. Also you can use killing spree safely while flying in the air but it will usually result in you missing a ring or 2. Where as Vendetta will not go to waste as it is just a damage boosting CD.

Couple thoughts I've pooled.

Shannox
Combat Readiness is a strong defensive ability against Rageface's Face Rage. One of the few times you'll have a use for it.

Beth'tilac
Feint and Cloak of Shadows works against Emberflare, but you can only feint every other Emberflare.
If your guild is low on snares, Deadly Brew is helpful to keep spiderlings slowed when/if you're on the ground.

Rhyolith
If you have any issues with staying in range during a stomp (say you're at the end of the hit box such that you have more time to avoid Magma Lines), running forwards at the end of a stomp can keep you in range the entire time.
If you're required by your guild to frequently target swap, WP/WP CAN be viable for Combat and Sub. The general rule of thumb is that IP/DP takes roughly 30 seconds to be superior (to WP/WP). Therefore if you end up swapping legs more often than that (improbable but possible), then you should think about using WP/WP.
Blade Flurry double dips in damage reduction, but it's still a DPS boost even at 80% damage reduction.

Baleroc
Killing Spree can relocated you to be closer than the person with the beam if other melee are not close enough.


Also, can someone else confirm that Killing Spree will immune the knockback and damage of a stomp from the Molten Lord trash? It may have been a fluke, but I haven't been able to double check it cause I only got a chance to kill 1 last night with KS up.


EDIT: It doesn't look like the damage is avoided via Killing Spree.

EDIT2: @Zellyn
The sentence was poorly worded, happens from time to time when you change a sentence a dozen times.

There were a couple attempts for me where Rageface would still be on me for a little bit after the stun wore off though. I'll just assume that's server latency though seeing as the spell data and relevant information implies he is supposed to target someone else as soon as Face Rage is broken.

KsP immunes knockbacks on both Molten Lords and the Fire Element spawned from the Salamander packs infront of Baleroc's room.

Can anyone find out if Smoldering Devastation can be cloaked? This might be a better use of the CD than the emberflare.

I think the problem - whether you can cloak it or not - is that the tank can't, and while evasion gives you a decent chance of surviving aggro until the tank gets back up, its far from a sure thing. Seems awfully risky.

Smoke bomb will not prevent Majordomo Staghelm from leaping at a random ranged player during cat phase.

The Magmaw trash before Ragnaros should not be Kspreed. You'll fall in the lava.

Anyone know if imp kick will silence the casters on Alysrazor?

Except that Face Rage has a stun component, so unless you're popping it preemptively I'm not sure how this really helps very much.

Targeting Rag during the little adds that spawn on everyone will still allow Blade Flurry to cleave the small adds.

I disarmed the traps that spawned inside melee, on Shannox encounter today. That was very helpful and actually made a huge difference on the encounter from having to kite Shannox too much. Its easy to disarm the traps and not haveing a very big dps loss. The disarming is just somewhat useful for stacking some energy, only dps you will loose if you time it right is the autoattacks the 1,5 sec it takes to disarm it. Say you have rupture up, and are on 5 cp and waiting to do an envenom. Haveing energy for two more mutilate after envenom is recomended in assassinationguide on this forum if I remember correctly. So you just save the enery before the envenom while disarming.

After disarming many traps today I was still at the top two on dps, even after changing targets and disarming more traps around when the dogs were killed.

So the benefit from disarming is a huge advantage and shouldnt be even considered not doing because of a slight dpsloss.

Feint does not seem to work for Majordomo Staghelm's Flame scythe

I was using Feint on cooldown for every Flame Scythe I could, and according to our logs for tonite I took significantly less damage from it then the rest of the raid. It could have been coincidence, but I'm almost positive it works.

I can say with great certainty that Feint does in fact work for Flame Scythe, here's a log for comparison. I missed 3 of the attacks but you get a pretty clear indication.

Don't ask me how I managed to find out, but Shadowstepping Ragnaros places you directly behind him, in the magma. I was able to Cloak/Sprint/Rocket Jump out safely, but... lesson learned.

You can Feint/CoS Alysrazor Firestorm and Feint definitively works on Fandral's Flame Scythe. You can also Feint Lord Rhyolith Concussive Stomp.