@YoRHa-2B said in A word of warning about the sale items in the AC shop:
My alliance friends used 400% and other boost, and still couldn't get his/her nemesis. While I manage to get 2 nemesis with only 50% triboost and 250% rdr.
It's worth mentioning how rare drops might be calculated.
As an example let's say 13* Nem or Slave has a 0.5% chance to drop (this number is surely inaccurate but just an example). If you were to use a 400% rare drop booster, you'd instead have a 2% drop chance. While this is obviously an increase, it's not much of one in the grand scheme of things. 2% is still very low and statistically speaking the odds are still very much against you. Also with how probability works universally...a boost is in no way a guarantee to get anything no matter how much your chances increase as long as that chance is lower than 100%.
In my opinion, you shouldn't use boosters for 13* drops because what you're gaining is negligible and your odds of obtaining a 13* is pretty close to someone who's not even using any boosts. Plus with the way probability and luck works, someone without boosts could simply just get more 13* drops compared to someone with heavy boosts. Just the way it works.
I personally believe rare boosts are best used for 10* to 12* farming where the odds are significantly more in your favor where the base drop chances actually see somewhat significant increases. But like before, probability won't guarantee anything. Always keep that in mind. Always.
As far as the 400% boost itself, I've heard very sketchy and conflicting reports. I don't think it's worth investing into simply because of probability and because of what I've heard about them simply not working or in some cases seemingly worsen one's drops.