Destiny’s success is based on a simple premise: keep people playing. The gameplay is good, the story is…not so much, but where Bungie Inc’s sci-fi shooter really excels is dangling the carrot of better gear in front of players’ noses in a manner similar to what MMO fans have called “the gear treadmill.”

While some players could grind for weeks or even months to gain certain items, the game has a built-in shortcut that a players can take advantage of to jump a few feet ahead on the gear treadmill. Every Friday, a vendor named Xûr appears somewhere in the game’s hub zone, the Tower. Xûr sells an assortment of rare items for incredibly cheap prices, Destiny power leveling to make upgrades easier and cheaper price, but he may not offer everything players want since his stock is random. Or at least, it is supposed to be.

Over the past month, Japanese-speaking Reddit user Megamanexe4 has accurately predicted not only the location where Xûr will show up each week, but also the specific items the vendor will have in stock. This undermines Bungie’s previous insistence that Xûr’s inventory and location are completely random.

The knowledge of what items will be sold by Xûr does not significantly affect  the game itself, but it does mean fewer players log in on Fridays when they already know that the vendor will not be selling any of the items they need. On the other hand, it also means some players will play more in the week leading up to the new items so that they can afford to by them when Xûr shows up. Apparently, that is enough to spur Bungie into changing the system so that Megamanexe4’s predictions no longer work.

According to his most recent Xûr prediction post on Reddit (with a rough translation by Reddit user balderm), Megamanexe4 is no longer able to query individual items from Xûr’s inventory, meaning that he cannot see what items will be in stock. He believes that Bungie may be stocking Xûr’s inventory manually to prevent the data from being mined and predicted.

Again, this seems to undermine Bungie’s previous stance that it could not affect Xûr’s items, which has some fans criticizing the studio for previously allowing the vendor to sell only items available to people who own the game’s DLC.