Back at the dawn of time, the debuff limit was 8. That means only 8 debuffs could be on a monster at any given time - which lead to severe restrictions when you had 40 players attacking the same thing in a raid environment. (You would either always have important debuffs being bumped off or you would have very strict raid rules which only allowed certain debuffs to be used by certain players.) And warlocks, whose DOT spells actually made up good portion of their damage done, were reduced to shadowbolting machines. The debuff limit was later doubled, and currently sits at 16, which allows for a lot more flexibility. However, recently the CMs dropped what I consider to be quite the bombshell: in the expansion, in addition to smaller raid size, the debuff limit will be increased again - to 40. Combined with 25-player raids, that's a heck of a lot of debuffs...!
Posts with tag debuff limit
There's a limited number of debuffs that can be placed on any target - currently, the maximum is 16. This is enough where it's not usually problematic, but in a raid environment it's not difficult to hit that maximum, and when you do, the oldest debuff on the target is bumped off in favor of the new one. This becomes a bit problematic when, for example, the short-lived "shadow vulnerability" debuff left by a warlock's improved shadow bolt talent starts bumping off more important things. To fix this, Blizzard has long been working on a system that prioritizes debuffs and leaves the most important ones on, while letting the less useful ones get bumped off. However, Tseric informs us that the "basic structure" of this prioritization system will be going live in patch 1.11 - to much rejoicing.