If you’ve never played World of Warcraft, you may be unfamiliar with the concept if not the visuals of tier sets. Tiered armor is the ultimate class-specific reward from each given raid level, so the upcoming Antorus raid awards Tier 21 armor for those lucky enough to get the necessary drops. Wearing several pieces of tier armor also awards set bonuses. But it looks like the time has passed on all of that, as a recent interview stated that tier sets are not planned to return at all in Battle for Azeroth.
Designer Ion Hazzikostas explains that tier pieces tend to “lock down” certain gear slots and feel like more of a hindrance than anything, so the team is experimenting with different ways to award gear and appearances. How that will work remains to be seen, but the suggestion of no more tier sets alone is a major departure from how World of Warcraft has always structured its endgame raids. We’ll hopefully learn more about these changes as the expansion gets closer to testing and release.