Achievement rarity comes to the Xbox One today for preview members. Mike Ybarra teased the new addition via Twitter and it looks like it’s a feature that will tell you how many players have unlocked the achievement. For example, a rare achievement might be one that only 10% of players had earned or something along those lines:
If you’re a Preview member feeling a little unique today, try and find what we hid in today’s update (11am)… #xbox pic.twitter.com/DTRRChplVk
— Mike Ybarra (@Qwik) September 22, 2016