Buff/debuff stacking might make useless debuffs (like lethargy) more useful. By stacking, I don’t mean the same player casting a debuff multiple times, but something like 10 or so people casting the same debuff on the same monster.
Again, using lethargy as an example, the flat reduction is garbage lategame. But at the very least, 20 stacks of lethargy on a boss would at least have some effect. Flat increase/decreases should stack additively, whilst percentage increases/decreases should stack diminishingly. Debuffs that cause stun/sleep should not stack at all.
What do you guys think?