Posting this in the Exploits section aswell, as i'm not sure if this is defined as a bug, trick, guide or an exploit. Up to the mods!
Huge exploit/trick involving vengeance & mitigation mechanics/abilites.
Any %damage reduction ability will work for this, however, the only actually relevant ones are the monk abilities Diffuse Magic & Zen Medidation. Anything from Barkskin to Guardian of Ancient Kings will also trigger this exploit, but in much smaller proportion. If you didn't figure it out already, this is dependant on the amount of reduction from the ability.
Server lag allows you to use this to gain ridicolous amounts of vengeance, example;
Tank runs away from Sha of Pride & gets Reaching Attack spammed. At the very end of the Reaching Attack cast, tank presses Diffuse Magic. This will (if timed correctly) cause the server to think that you took a full hit of reaching attack with your Diffuse Magic up, which is a 90% magic damage reduction. This will give you 10 times the amount of vengeance that you should normally get.
It's fairly easy to time this after you got the hang of it - It's useable on every boss in diffrent ways, as Zen Meditation also reduces damage from Physical abilities, you can use it for melee attacks aswell as spells.
Some obvious spells this is nice for;
Immersus: Corrosive Blast
Protectors: Calamity (fairly hard to time this sometimes)
Sha of Pride: Reaching Attack And/Or Swelling Pride
Dark Shamans: Froststorm Bolt (Cast by Wavebinder Kadris)
Nazgrim: Execute
Thok: Any melee attack (assuming you're solotanking) at around 5 stacks of the debuff in P1, as this'll cap you.
Siegecrafter: Electrostatic shock will work for this, but it's also quite hard to get right.
Garrosh: Annihilate. More detailed guide on how to do this here; http://www.ownedcore.com/forums/worl...sh-heroic.html (BM Monk Vengeance Cap Exploit - Garrosh Heroic)
Besides this, if you macro Diffuse Magic & Zen Meditation into the same macro like so;
Code:
#showtooltip
/cast Diffuse Magic
/cast Zen Meditation
Timing this correctly will instead give you 100 times the vengeance rather than 10.
Best of luck 
Originally Posted by
Saionara
Wrote this, went to sleep, woke up to 16 comments.. Clearing some things up (will also change the main post):
If you stand in (examples, yay!) Annihilate on Garrosh Hellscream you'll get about 2-300k vengeance. Using this exploit will vengeance cap you. Again, as mentioned in the original post, vengeance gets incorrectly calculated because of the timing of which you use Diffuse Magic or Zen Meditation. It calculates vengeance thinking that you took the same amount of damage but through a 90% reduction, which is why it gives you 10 times the amount of vengeance. If combined with Zen Meditation & timed correctly, it'll calculate your vengeance as taking the original hit with 99% damage reduction, which will in most cases vengeance cap you.
No, rogues cannot use this as Vengeance is only availible to Tank specced characters. All of you clueless people saying this is intended, please go away..
Explanation #2, credit to Nogrim.
Originally Posted by
Norgrim
I will use your example to explain (if I understood it correctly)
Frostbolt does 100k dmg. You pop difuse magic right when frostbolt is about to hit you. It hits for 100k, due to some server lag (no reduction). The game, however, recognizes that you had difuse magic up when the frostbolt hit you, and since you took 100k dmg, it thinks that this is the dmg AFTER the reduction, giving you vengence as if the frostbolt was 1.000k dmg, ten times bigger.
Since zen med works the same way, IF it works (I didnt test it), it would give you 100 times more vengeance from a single attack.
Video of this in action (Thanks to SmallSnowball for posting & Credit to Wannoob79 (Uploader)
Originally Posted by
SmallSnowball
first annihilate, monk executes the exploit, for those who want the video