Dungeon Set Bonuses and Mixing Pieces

What changed, and who says so

Blizzard has confirmed only the direction. Its Deep Dive recap says set bonuses “have been improved to feel more useful and exciting” and that unique dungeon boss items are now blue quality. The new piece counts come from beta data: as summarised in Wowdee's tier-set guide, beta trackers agree the Classic Tier 0 and 0.5 dungeon sets moved from bonuses at 2, 4, 6 and 8 pieces to 2, 3, 4, 5 and 6, and the 8-piece bonus is gone.

Blizzard hasn't published those thresholds itself, or what the new bonuses do.

Mixing two sets under the new counts

With a bonus at every count from 2 to 6, splitting slots between sets costs less than it did in Classic. Each set still counts only its own pieces, so under the reported thresholds, and assuming the sets keep their eight Classic slots, an eight-slot split works out like this:

The decision you can make now

Which split suits you depends on what each bonus does, and nobody can answer that from official information yet. The top end is clearer: with nothing reported above six pieces, chasing the last two pieces of an eight-piece set no longer unlocks anything. Those two slots can go to whichever blue dungeon drop suits your character better.

Smaller leveling-dungeon sets

The reported threshold change covers Tier 0 and 0.5 specifically. Classic also had smaller sets from leveling dungeons, and the recap's wording covers set bonuses in general, but no source behind this guide gives their new piece counts or effects. Check each set's tooltip before you build around it.

Dungeon itemization is still moving in the beta, too. Blizzard's October 8 development notes lowered various dungeon quest rewards from Rare to Uncommon and changed their stats to match.