Stagger is a passive level 10 Brewmaster ability that causes a portion of incoming physical damage to be dealt over 10 seconds rather than instantly.
For each hit taken, the damage that is stored in Stagger is recalculated and the dot refreshed. The key thing here is that Stagger by itself does not mitigate damage, but instead smooths it out. Also, Stagger by itself will not kill a Brewmaster monk. You can be at 1 health with only stagger ticking and not die, but in a raid there are a lot of things that can take that last point.
The Stagger DoT has three "Phases": Light Stagger, Moderate Stagger, and Heavy Stagger. Light Stagger is when the total stagger amount is less than 30% of max health. Moderate Stagger is when the total stagger amount is more than 30% of max health, but less than 60%. Finally, Heavy Stagger is when the total stagger amount is greater than 60% of max health.
A monk has 600k health and has 20% (Stance) + 20% (Shuffle) + 10% (Mastery) = 50% Stagger. They gets hit for 500k physical damage. With 50% stagger, the monk takes 500k * .5 (50%) = 250k, and the other 250k is applied as a dot that will tick for 250k / 10 = 25k per sec for 10 sec. One tick went through, but they manage to use Purifying Brew before the second tick to remove the rest of the staggered damage. Thus the total damage taken is 250k (initial hit) + 25k (first stagger tick) = 275k.
500k - 275k = 225k damage not taken.
Patches and hotfixes
- Patch 7.2.5 (2017-06-13): Staggered damage cannot exceed 1000% of your maximum health.
- Patch 7.1.5 (2017-01-10): Is now 40% more effective against magical attacks.
- Hotfix (2016-10-03): "Stagger now delays 40% of damage taken (was 35%), and now quickly fades after leaving combat."
- Patch 7.0.3 (2016-07-19): Redesigned, replacing .
- Hotfix (2013-03-27): "Tier-15 Brewmaster Monk 2-piece set bonus should now correctly increase Stagger by 12%."
- Patch 5.2.0 (2013-03-05): Tooltip now includes the amount of stagger remaining.
- Patch 5.0.4 (2012-08-28): Added.