Link up top for the math to prove it: https://docs.google.com/spreadsheets/d/1IYhBoebydycePznhbX9LZTihNEjSwdsAsKkj9uQmRG8/edit?usp=sharing
At the start of the season when the list of challenges was datamined I quickly noticed a big difference compared to Season of the Chosen: there was an extra multiplier for XP and BD. Because of that, it was obvious that some tiers would need to grant the same level of Bright Dust, those being x1 and x2. Until Week 5 we didn't see any x4 and x8 to confirm the 150 and 300BD payouts.
With the payouts confirmed, the total sum for the individual challenges came out to 5475 Bright Dust rather than 6000 as it was last season. This week we all reached the point where we could acquire the big payout for 75 Challenges completed, which as expected, was a flat 4000 instead of 4525 to adjust for the reduced BD on the rest of the Challenges.
Now, why is this a problem, you may ask?
Here’s a quick breakdown of how much Bright Dust you should expect to earn over the course of Season 13. Seasonal Challenges Bright Dust (All Players)
Free Seasonal Activities – 6,000
Seasonal Extra – 4,000
Total – 10,000 Bright Dust
For S13 Bungie announced a total 10k BD from Challenges for all players, implying that it would be the standard going forward (seeing as the Season Pass BD is always the same as well). But instead, it saw a small enough reduction that most people wouldn't notice unless they were keeping track of it. And if their intention was not to keep the total the same across seasons, it should have been mentioned back in that TWAB or at the very least with the launch of Season 14.
Edit: I mean, if the Season Pass Bright Dust (which are fixed rewards) didn't see any change, why should the Challenges not also have a predetermined payout guaranteed across seasons?External link →